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  • Gold Nanorod Embedded Novel 3D Graphene Nanocomposite for Selective Bio-capture in Rapid Detection of Mycobacterium tuberculosis
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-25
    Veeradasan Perumal, Mohamed Shuaib Mohamed Saheed, Norani Muti Mohamed, Mohamed Salleh Mohamed Saheed, Satisvar Sundera Murthe, Subash C.B. Gopinath, Jian-Ming Chiu

    Tuberculosis (TB) is a chronic and infectious airborne disease which requires a diagnosing system with high sensitivity and specificity. However, the traditional gold standard method for TB detection remains unreliable with low specificity and sensitivity. Nanostructured composite materials coupled with impedimetric sensing utilised in this study offered a feasible solution. Herein, novel gold (Au) nanorods were synthesised on 3D graphene grown by chemical vapour deposition. The irregularly spaced and rippled morphology of 3D graphene provided a path for Au nanoparticles to self-assemble and form rod-like structures on the surface of the 3D graphene. The formation of Au nanorods were showcased through scanning electron microscopy which revealed the evolution of Au nanoparticle into Au islets. Eventually, it formed nanorods possessing lengths of ~150 nm and diameters of ~30 nm. The X-ray diffractogram displayed appropriate peaks suitable to defect-free and high crystalline graphene with face centred cubic Au. The strong optical interrelation between Au nanorod and 3D graphene was elucidated by Raman spectroscopy analysis. Furthermore, the anchored Au nanorods on 3D graphene nanocomposite enables feasible bio-capturing on the exposed Au surface on defect free graphene. The impedimetric sensing of DNA sequence from TB on 3D graphene/Au nanocomposite revealed a remarkable wide detection linear range from 10 fM to 0.1 µM, displays the capablity of detecting femtomolar DNA concentration. Overall, the novel 3D graphene/Au nanocomposite demonstrated here offers high-performance bio-sensing and opens a new avenue for TB detection.

    更新日期:2018-05-27
  • 更新日期:2018-05-27
  • Nano-biosensor for highly sensitive detection of HER2 positive breast cancer
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-25
    Razieh Salahandish, Ali Ghaffarinejad, Seyed Morteza Naghib, Keivan Majidzadeh-A, Hossein Zargartalebi, Amir Sanati-Nezhad

    Nanocomposite materials have provided a wide range of conductivity, sensitivity, selectivity and linear response for electrochemical biosensors. However, the detection of rare cells at single cell level requires a new class of nanocomposite-coated electrodes with exceptional sensitivity and specificity. We recently developed a construct of gold nanoparticle-grafted functionalized graphene and nanostructured polyaniline (PANI) for high-performance biosensing within a very wide linear response and selective performance. Further, replacing the expensive gold nanoparticles with low-cost silver nanoparticles as well as optimizing the nanocomposite synthesis and functionalization protocols on the electrode surface in this work enabled us to develop ultrasensitive nanocomposites for label-free detection of breast cancer cells. The sensor presented a fast response time of 30 min within a dynamic range of 10 − 5×106 cells.mL−1 and with a detection limit of 2 cells.mL−1 for the detection of SK-BR3 breast cancer cell. The nano-biosensor, for the first time, demonstrated a high efficiency of ˃ 90% for the label-free detection of cancer cells in whole blood sample without any need for sample preparation and cell staining. The results demonstrated that the optimized nanocomposite developed in this work is a promising nanomaterial for electrochemical biosensing and with the potential applications in electro-catalysis and super-capacitances.

    更新日期:2018-05-27
  • Interferometric nanoimmunosensor for label-free and real-time monitoring of Irgarol 1051 in seawater
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-26
    Blanca Chocarro-Ruiz, Sonia Herranz, Adrián Fernández Gavela, Josep Sanchís, Marinella Farré, M. Pilar Marco, Laura M. Lechuga

    An interferometric nanobiosensor for the specific and label-free detection of the pollutant Irgarol 1051 directly in seawater has been settled. Due to the low molecular weight of Irgarol pollutant and its expected low concentration in seawater, the sensor is based on a competitive inhibition immunoassay. Parameters as surface biofunctionalization, concentration of the selective antibody and regeneration conditions have been carefully evaluated. The optimized immunosensor shows a limit of detection of only 3 ng/L, well below the 16 ng/L set by the EU as the maximum allowable concentration in seawater. It can properly operate during 30 assay-regeneration cycles using the same sensor biosurface and with a time-to-result of only 20 min for each cycle. Moreover, the interferometric nanosensor is able to directly detect low concentrations of Irgarol 1051 in seawater without requiring sample pre-treatments and without showing any background signal due to sea matrix effect.

    更新日期:2018-05-27
  • Technological advancement in electrochemical biosensor based detection of Organophosphate pesticide chlorpyrifos in the environment: A review of status and prospects
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-26
    Shivani Uniyal, Rajesh Kumar Sharma

    Chlorpyrifos (CP), an organophosphate insecticide is broadly used in the agricultural and industrial sectors to control a broad-spectrum of insects of economically important crops. CP detection has been gaining prominence due to its widespread contamination in different environmental matrices, high acute toxicity, and potential to cause long-term environmental and ecological damage even at trace levels. Traditional chromatographic methods for CP detection are complex and require sample preparation and highly skilled personnel for their operation. Over the past decades, electrochemical biosensors have emerged as a promising technology for CP detection as these circumvent deficiencies associated with classical chromatographic techniques. The advantageous features such as appreciable detection limit, miniaturization, sensitivity, low-cost and onsite detection potential are the propulsive force towards sustainable growth of electrochemical biosensing platforms. Recent development in enzyme immobilization methods, novel surface modifications, nanotechnology and fabrication techniques signify a foremost possibility for the design of electrochemical biosensing platforms with improved sensitivity and selectivity. The prime objective of this review is to accentuate the recent advances in the design of biosensing platforms based on diverse biomolecules and biomimetic molecules with unique properties, which would potentially fascinate their applicability for detection of CP residues in real samples. The review also covers the sensing principle of the prime biomolecule and biomimetic molecule based electrochemical biosensors along with their analytical performance, advantages and shortcomings. Present challenges and future outlooks in the field of electrochemical biosensors based CP detection are also discussed. This deep analysis of electrochemical biosensors will provide research directions for further approaching towards commercial development of the broad range of organophosphorus compounds.

    更新日期:2018-05-27
  • MNPs@anionic MOFs/ERGO with the size selectivity for the electrochemical determination of H2O2 released from living cells
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-26
    Cong Li, Ruijun Wu, Juncheng Zou, Tingting Zhang, Sufang Zhang, Zhiquan Zhang, Xin Hu, Youqi Yan, Xiaomei Ling

    Herein, the ternary composites, ultrasmall metal nanoparticles encapsulated in the anionic metal-organic frameworks/electrochemically reduced graphene oxide (MNPs@Y-1, 4-NDC-MOF/ERGO, M = Ag, Cu) was constructed by a cationic exchange strategy and an electrochemical reduction process for the electrochemical determination of H2O2. Both AgNPs@Y-1, 4-NDC-MOF/ERGO and CuNPs@Y-1, 4-NDC-MOF/ERGO display excellent electrocatalytic activities toward H2O2, but the former is superior to the latter. Such a difference in electrocatalytic activities can be explained by the characterization measurements, and the results manifest MNPs@Y-1, 4-NDC-MOF/ERGO (M = Ag, Cu) electrocatalysts have subequal MNPs sizes and electrochemical surface areas, but different electron transfer rate constants. The AgNPs@Y-1, 4-NDC-MOF/ERGO sensor shows a linear detection range from 4 to 11000 μM with the detection limit of 0.18 μM. Moreover, MNPs@Y-1, 4-NDC-MOF/ERGO (M = Ag, Cu) exhibit excellent anti-interference performance and can be used for the detection of H2O2 released from living cells. The proposed sensor takes full advantage of the catalytic property of MNPs, the size selectivity of Y-1, 4-NDC-MOF, and the fast electron transport effect of ERGO. Thus, the MNPs@Y-1, 4-NDC-MOF/ERGO/GCE (M = Ag, Cu) can be utilized to detect oxidase activities by monitoring H2O2 produced in the presence of substrate and oxidase, and it is expected that composites with the molecular sieving effect and catalytic activity can be widely applied for catalysis, biomedicine, and biosensing fields.

    更新日期:2018-05-27
  • 更新日期:2018-05-27
  • Electroactive Au@Ag nanoparticles driven electrochemical sensor for endogenous H2S detection
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-26
    Yuan Zhao, Yaxin Yang, Linyan Cui, Fangjie Zheng, Qijun Song

    In this work, a novel and facile electrochemical sensor is reported for the highly selective and sensitive detection of dissolved hydrogen sulfide (H2S), attributing to the redox reaction between Au@Ag core-shell nanoparticles (Au@Ag NPs) and H2S. Electroactive Au@Ag NPs not only possess excellent conductivity, but exhibit great electrochemical reactivity at 0.26 V due to the electrochemical oxidation from Ag° to Ag+. In the presence of H2S, the Ag shell of Au@Ag NPs can be oxidized to Ag2S, resulting in the decrease of differential pulse voltammetry (DPV) peak at 0.26 V. The electrochemical sensor exhibits a wide linear response range from 0.1 nM to 500 nM. The limit of detection (LOD) for H2S is as low as 0.04 nM. The developed sensor shows significant prospects in the study of pathological processes related to the mechanism of H2S production.

    更新日期:2018-05-27
  • Real-time circulating tumor cells detection via highly sensitive needle-like cytosensor-demonstrated by a blood flow simulation
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-24
    Wen-Hui Weng, I-Lin Ho, Chi-Chia Pang, Sow-Neng Pang, Tung-Ming Pan, Wai-Hung Leung

    The concept of rapid detection of circulating tumor cells (CTCs) has always been the focal point of modern and future medicine. However, the dispersity and rarity of CTCs in the bloodstream makes it hard to detect metastasis. Herein, our newly designed needle-like cytosensor demonstrates that the capture and analysis of CTCs are a much less laborious process and have more potential than ever. Our aim is to detect and capture CTCs directly in the bloodstream without altering the genetic information; further benefit of current cytosensor is allows for the whole circulation of blood to run through the cytosensor, giving a much better sensitivity and chance of detecting CTCs. Our functionalized needle-like cytosensor has been modified with 3-aminopropyltriethoxysilane, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, N-hydroxysuccinimide and conjugated streptavidin to allow the binding of the biotinylated-antibody of epithelial cell adhesion molecules, which captures targeted colon cancer CTC. The capability of our needle-like cytosensor to detect CTCs spanned from 102 to 106 cells/mL. Beyond this, the needle-like cytosensor avoids the distortion of the cell information. In addition, we constructed a blood flow simulation that mimics human circulating system about 10 mL/min speed; by using cyclic voltammetry we could detect significant signals from captured cancer CTCs more than 21 cells/mL without delay; the fluorescence dye detection was further performed for data confirmation. The future of biosensors begins with this, by providing early monitoring quality care in cancer therapy.

    更新日期:2018-05-25
  • Recent trends in electrochemical biosensors of superoxide dismutases
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-24
    Murugesan Balamurugan, Paulraj Santharaman, Thangamuthu Madasamy, Seenivasan Rajesh, Niroj Kumar Sethy, Kalpana Bhargava, Srigiridhar Kotamraju, Chandran Karunakaran

    Superoxide dismutases (SODs), a family of ubiquitous enzymes, provide essential protection to biological systems against uncontrolled reactions with oxygen- and nitrogen- based radical species. We review first the role of SODs in oxidative stress and the other biological functions such as peroxidase, nitrite oxidase, thiol oxidase activities etc., implicating its role in neurodegenerative, cardiovascular diseases, and ageing. Also, this review focuses on the development of electrochemical label-free immunosensor for SOD1 and the recent advances in biosensing assay methods based on their catalytic and biological functions with various substrates including reactive oxygen species (superoxide anion radical, hydrogen peroxide), nitric oxide metabolites (nitrite, nitrate) and thiols using thiol oxidase activity. Furthermore, we emphasize the progress made in improving the detection performance through incorporation of the SOD into conducting polymers and nanocomposite matrices. In addition, we address the potential opportunities, challenges, advances in electrochemical-sensing platforms and development of portable analyzer for point-of-care applications.

    更新日期:2018-05-25
  • Wearable humidity sensor based on porous graphene network for respiration monitoring
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-25
    Yu Pang, Jinming Jian, Tao Tu, Zhen Yang, Jiang Ling, Yuxing Li, Xuefeng Wang, Yancong Qiao, He Tian, Yi Yang, Tian-Ling Ren

    Respiration is as one of the most essential physiological signals, which can be used to monitor human healthcare and activities. Herein, we report a flexible, lightweight and highly conductive porous graphene network as the humidity sensor for respiration monitoring. To enhance the sensing performance, the graphene oxide (GO), poly (3, 4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT: PSS) and Ag colloids (AC) were used to modify the porous graphene. The humidity properties of porous based graphene networks have been investigated at different relative humidity (RH). The porous based graphene sensors exhibit excellent capability of monitoring different breathing patterns including mouse and nose respiration, normal and deep respiration. Besides, the signal variations before and after water intake was recorded by the sensor, which demonstrates the ability to monitor water loss during breathing period. Furthermore, the humidity sensor shows the ability to detect physiological activities including skin moisture, speaking and whistle rhythm, which could be a promising electronic for clinical respiration monitoring.

    更新日期:2018-05-25
  • Ultrasensitive photoelectrochemical immunosensor of cardiac troponin I detection based on dual inhibition effect of Ag@Cu2O core-shell submicron-particles on CdS QDs sensitized TiO2 nanosheets
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-24
    Jie Chen, Ling Kong, Xiaokai Sun, Jinhui Feng, Zhiwei Chen, Dawei Fan, Qin Wei

    Rapidity and high sensitivity are the critical factors for the diagnoses of heart attacks and cardiac troponin I (cTnI) is used as a gold standard marker for its diagnosis. To realize the accurate detection of cTnI, a novel ultrasensitive photoelectrochemical (PEC) immunosensor for cTnI determination was developed upon dual inhibition effect of Ag@Cu2O core-shell submicron-particles(SPs) toward CdS sensitized the (001) facets of anatase titanium dioxide nanosheets (TiO2/CdS). In this study, the TiO2/CdS composite not only indicated stable and excellent photoelectric signal but also provided abundant functional group to immobilized cTnI antibodies (Ab1). To obtain the high sensitivity, Ag@Cu2O core-shell SPs were used as labels of the secondary antibodies (Ab2), owning to competitive absorption of light and consumption of electron donor, less light energy and electron donors arrived at the TiO2/CdS sensitization structure. Besides, the remarkable steric hindrance effect of Ag@Cu2O core-shell SPs labeled secondary antibodies (Ab2) conjugates obstructed the transfer of electrons and diffusion of the electron donors to the photoelectrode surface, leading to further decrease of photocurrent. Therefore, the constructed immunosensor has an ultrasensitive response to cTnI in a liner range of 0.02 pg/mL to 50 ng/mL with a low detection limit of 6.7 fg/mL, and exhibits good sensitivity and admirable stability. Moreover, the strategy provided an efficient and novel approach for dual inhibition effect in PEC immunoassay development.

    更新日期:2018-05-24
  • Enhanced Photoelectrochemical DNA Sensor Based on TiO2/Au Hybrid Structure
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-23
    Xing-Pei Liu, Jing-Shuai Chen, Chang-jie Mao, He-Lin Niu, Ji-Ming Song, Bao-Kang Jin

    A novel enhanced photoelectrochemical DNA sensor, based on a TiO2/Au hybrid electrode structure, was developed to detect target DNA. The sensor was developed by successively modifying fluorine-tin oxide (FTO) electrodes with TiO2 nanoparticles, gold (Au) nanoparticles, hairpin DNA (DNA1), and CdSe-COOH quantum dots (QDs), which acted as signal amplification factors. In the absence of target DNA, the incubated DNA1 hairpin and the CdSe-COOH QDs were in close contact with the TiO2/Au electrode surface, leading to an enhanced photocurrent intensity due to the sensitization effect. After incubation of the modified electrode with the target DNA, the hairpin DNA changed into a double helix structure, and the CdSe QDs moved away from the TiO2/Au electrode surface, leading to a decreased sensitization effect and photoelectrochemical signal intensity. This novel DNA sensor exhibited stable, sensitive and reproducible detection of DNA from 0.1 μM to 10 fM, with a lower detection limit of 3 fM. It provided good specificity, reproducibility, stability and is a promising strategy for the detection of a variety of other DNA targets, for early clinical diagnosis of various diseases.

    更新日期:2018-05-24
  • Nanotechnology-based Electrochemical Detection Strategies for Hypertension Markers
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-23
    Madhurantakam Sasya, Jayanth Babu K, John Bosco Balaguru Rayappan, Uma Maheswari Krishnan

    Hypertension results due to dysfunction of different metabolic pathways leading to the increased risk of cerebral ischemia, atherosclerosis, cardiovascular and inflammatory disorders. Hypertension has been considered a one of the major contributors to metabolic syndrome and is often referred to as a ‘silent killer’. Its incidence is on the rise across the globe owing to the drastic life style changes. The diagnosis of hypertension had been traditionally carried out through measurement of systolic and diastolic blood pressure but in most cases, this form of diagnosis is too late and the disease has already caused organ damage. Therefore, early detection of hypertension by monitoring subtle changes in specific biochemical markers from body fluids can minimize the risk of organ damage. However, a single marker may be insufficient for accurate diagnosis of hypertension thereby necessitating quantification of multiple markers. Concerted efforts to identify key markers for hypertension and their quantification, especially using chemical and biosensors, are underway in different parts of the world. Constant evolution of the sensing elements and transduction strategies have contributed to significant improvements in the diagnosis field, especially in the context of sensitivity, response time and selectivity and this when applied to the detection of hypertension markers may prove beneficial. This review summarizes advances in the field of sensor technology towards the detection of biologically relevant entities, arrays and the next generation ‘lab-on-a-chip’ systems for hypertension.

    更新日期:2018-05-24
  • Interferon gamma transcript detection on T cells based on magnetic actuation and multiplex double-tagging electrochemical genosensing
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-22
    Soledad Carinelli, Cristina Xufré, Mercè Martí, María Isabel Pividori

    Interferon-γ is a proinflammatory cytokine, and its production is related with effective host defense against intracellular pathogens. Therefore, the level of interferon-γ is considered a good biomarker for intracellular infections. It is also useful for the assessment, treatment progression and follow-up of non-communicable diseases, including cancer and autoimmune disorders, among others. This work addresses the development of a novel Interferon-γ release assay (IGRA) to evaluate the expression of interferon-γ transcripts as biomarker, produced by isolated T cells as a main advantage. The method sequentially combined three different types of magnetic separation, including the immunomagnetic separation of the T cells performed on antiCD3 modified magnetic particles, the retrotranscription and multiplex double-tagging PCR on polydT-modified magnetic particles and, finally, the electrochemical genosensing on streptavidin magnetic particles as a support. This approach is able to quantify the levels of cellular interferon-γ produced by as low as 150 T cells with outstanding analytical features. The detection of interferon-γ transcripts is performed from only 100 μL of whole blood which can be potentially obtained by fingerprick, demonstrating a further clear advantage to be considered as a promising strategy for the quantification of this important biomarker in several clinical applications.

    更新日期:2018-05-23
  • Highly Sensitive Electrochemiluminescence Immunosensor based on ABEI/H2O2 System with PFO Dots as Enhancer for Detection of Kidney Injury Molecule-1
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-22
    Huiyun Yang, Haijun Wang, Chengyi Xiong, Yaqin Chai, Ruo Yuan

    In this work, poly[9,9-dioctylfluorenyl-2,7-diyl] (PFO) dots is discovered to display an appealing dual enhancement effect for the electrochemiluminescence (ECL) system of N-(aminobutyl)-N-(ethylisoluminol)/hydrogen peroxide (ABEI/H2O2), which not only enhances the ECL intensity of ABEI but also catalyzes decomposition of H2O2 to further amplify the ECL signal of ABEI. Owing to the electronegative property of PFO dots, electropositive ABEI-PEI as ECL reagent could be adsorbed on their surface and thus form a novel luminescence emitter (ABEI-PEI-PFO dots) with high ECL efficiency based on electrostatic attraction. Meanwhile, the water solubility and stability of this emitter are improved in virtue of the amine-rich property of ECL reagent (ABEI-PEI), which could increase the luminous efficiency of ECL reaction in aqueous solution. To increase the electron transfer efficiency, Pt nanoparticles (PtNPs) supported on reduced graphene oxide nanosheets (RGOs) via a onepot synthetic strategy are chosen as immobilizing platform for the ECL emitter (ABEI-PEI-PFO dots). Herein, the obtained dual-amplifed ABEI-PEI-PFO dots-RGOs/PtNPs complex is served as an ideal nanocarrier to capture detection antibody (Ab2). According to sandwiched immunoreaction, a highly sensitive ECL immunosensor is constructed for the detection of kidney injury molecule-1 (KIM-1) with a linearity from 50 fg mL−1 to 1 ng mL−1 and a detection limit of 16.7 fg mL−1. The developed ECL emitter combining dual amplified property for signal enhancement purpose would provide new thought and potential for sensitive bioanalysis and clinical application.

    更新日期:2018-05-23
  • Scalable Long-term Extraction of Photosynthetic Electrons by Simple Sandwiching of Nanoelectrode Array with Densely-packed Algal Cell Film
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-22
    Yong Jae Kim, JaeHyoung Yun, SeonIl Kim, Hyeonaug Hong, Jun-Hee Park, Jae-Chul Pyun, WonHyoung Ryu

    Direct extraction of photosynthetic electrons from the whole photosynthetic cells such as plant cells or algal cells can be highly efficient and sustainable compared to other approaches based on isolated photosynthetic apparatus such as photosystems I, II, and thylakoid membranes. However, insertion of nanoelectrodes (NEs) into individual cells are time-consuming and unsuitable for scale-up processes. We propose simple and efficient insertion of massively-populated NEs into cell films in which algal cells are densely packed in a monolayer. After stacking the cell film over an NE array, gentle pressing of the stack allows a large number of NEs to be inserted into the cells in the cell film. The NE array was fabricated by metal-assisted chemical etching (MAC-etching) followed by additional steps of wet oxidation and oxide etching. The cell film was prepared by mixing highly concentrated algal cells with alginate hydrogel. Up to photosynthetic currents of 106 nA/cm2 was achieved without aid of mediators, and the photosynthetic function was maintained for 6 days after NE array insertion into algal cells.

    更新日期:2018-05-23
  • Highly Selective Aptamer based Organic Electrochemical Biosensor with Pico-Level Detection ☆
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-22
    Nileshi Saraf, Eric R. Woods, Madison Peppler, Sudipta Seal

    An organic aptamer functionalized electrochemical transistor has been developed to detect the presence of epinephrine molecule which acts as an excitatory neurotransmitter. The abnormalities in the level of epinephrine are the direct symptoms of some diseases such as Takotsubo cardiomyopathy, myocardial infarction, arrhythmias and other heart related diseases. The present approach is based on immobilization of aptamers on the gate electrode which selectively binds to epinephrine with high affinity. The introduction of epinephrine in the system causes screening of negative charge of aptamers as well as the production of Faradaic current due to oxidation of epinephrine. The synergistic effect of these two events decreases the overall channel current which was seen in both transfer characteristics and current-time curve. Additional experiments against common interfering agents (dopamine, ascorbic acid, DOPAC etc) showed no decrease in the current which indicates high specificity of the sensor. Overall, the incorporation of aptamers in the transistor has allowed us to obtain a sensor exhibiting the lowest limit of detection for epinephrine (90 pM) till date which is comparable to normal physiological level. This approach provides a real-time detection of a large range of biomolecules and viral proteins in a time and cost-effective manner and has applications in point-of-care testing tool for several diagnostic applications.

    更新日期:2018-05-23
  • Sample-to-answer palm-sized nucleic acid testing device towards low-cost malaria mass screening
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-19
    Gihoon Choi, Theodore Prince, Jun Miao, Liwang Cui, Weihua Guan

    The effectiveness of malaria screening and treatment highly depends on the low-cost access to the highly sensitive and specific malaria test. We report a real-time fluorescence nucleic acid testing device for malaria field detection with automated and scalable sample preparation capability. The device consists a compact analyzer and a disposable microfluidic reagent compact disc. The parasite DNA sample preparation and subsequent real-time LAMP detection were seamlessly integrated on a single microfluidic compact disc, driven by energy efficient non-centrifuge based magnetic field interactions. Each disc contains four parallel testing units which could be configured either as four identical tests or as four species-specific tests. When configured as species-specific tests, it could identify two of the most life-threatening malaria species (P. falciparum and P. vivax). The NAT device is capable of processing four samples simultaneously within 50 min turnaround time. It achieves a detection limit of ~0.5 parasites/µl for whole blood, sufficient for detecting asymptomatic parasite carriers. The combination of the sensitivity, specificity, cost, and scalable sample preparation suggests the real-time fluorescence LAMP device could be particularly useful for malaria screening in the field settings.

    更新日期:2018-05-19
  • Film Bulk Acoustic Resonators (FBARs) as Biosensors: A Review
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-18
    Yi Zhang, Jikui Luo, Andrew J. Flewitt, Zhiqiang Cai, Xiubo Zhao

    Biosensors play important roles in different applications such as medical diagnostics, environmental monitoring, food safety, and the study of biomolecular interactions. Highly sensitive, label-free and disposable biosensors are particularly desired for many clinical applications. In the past decade, film bulk acoustic resonators (FBARs) have been developed as biosensors because of their high resonant frequency and small base mass (hence greater sensitivity), lower cost, label-free capability and small size. This paper reviews the piezoelectric materials used for FBARs, the optimisation of device structures, and their applications as biosensors in a wide range of biological applications such as the detection of antigens, DNAs and small biomolecules. Their integration with microfluidic devices and high-throughput detection are also discussed.

    更新日期:2018-05-18
  • Cascading reaction of arginase and urease on a graphene-based FET for ultrasensitive, real-time detection of arginine
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-16
    Teresa Berninger, Christina Bliem, Esteban Piccinini, Omar Azzaroni, Wolfgang Knoll
    更新日期:2018-05-16
  • pH responsive label-assisted click chemistry triggered sensitivity amplification for ultrasensitive electrochemical detection of carbohydrate antigen 24-2
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-15
    Yun Zheng, Lihua Zhao, Zhanfang Ma

    Sensitivity amplification strategy by implementing click chemistry in the construction of biosensing interface can efficiently improve the performance of immunosensor. Herein, we developed a sandwich-type amperometric immunosensor for ultrasensitive detection of carbohydrate antigen 24-2 (CA 242) based on pH responsive label-assisted click chemistry triggered sensitivity amplification strategy. The sensitivity of amperometric immunosensor relies on the current response differences (ΔI) caused by per unit concentration target analyte. The pH responsive Cu2+-loaded polydopamine (CuPDA) particles conjugated with detection antibodies were employed as labels, which can release Cu(II) ions by regulating pH. In the presence of ascorbic acid (reductant), Cu(II) ions were reduced to Cu(I) ions. Azide-functionalized double-stranded DNA (dsDNA) as signal enhancer was immobilized on the substrate through Cu+-catalyzed azide/alkyne cycloaddition reaction. With the help of the click reaction, the ΔI caused by target was elevated prominently, resulting in sensitivity amplification of the immunosensor. Under optimal condition, the proposed immunosensor exhibited excellent performance with linear range from 0.0001 to 100 U mL−1 and ultralow detection limit of 20.74 μU mL−1. This work successfully combines click chemistry with pH-responsive labels in sandwich-type amperometric immunosensor, providing a promising sensitivity amplification strategy to construct immunosensing platform for analysis of other tumor marker.

    更新日期:2018-05-16
  • Probing the Specific Binding of Folic Acid to Folate Receptor using Amino-functionalized Mesoporous Silica Nanoparticles for Differentiation of MCF 7 Tumoral Cells from MCF 10A
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-15
    Jafar Soleymani, Mohammad Hasanzadeh, Mohammad Hossein Somi, Nasrin Shadjou, Abolghasem Jouyban

    Folate receptor (FR) is overexpressed in various cancer cells while its expression in normal cells is restricted. The present study provides a new folic acid/folate (FA) functionalized nanomaterials to sense and the differentiation of the cancer cells from normal ones. The reported nanoprobe is based on the mesoporous materials that are functionalized with FA to specify the FR overexpressed cancerous cells. MCF 7 cell lines were used as a model to show the ability of the developed probe for cancer cell detection. The selective binding of FA to FR-positive cells causes the endocytosis of the mesoporous materials into the cells where it can be observed by fluorescence microscopy images. The specific nature of the binding of the FA functionalized mesoporous silica prevents the false detection of normal cells from cancerous cells even in the presence of each other. The cytotoxity of the n-Pr-NH2-MCM 41-FA on the MCF 7 cells was investigated using MTT assay. The reported method can detect the MCF 7 cells from 100 to 1000 cells/mL. This method provides a selective and nontoxic approach towards detection of breast cancer cell lines while it can be developed as a point of care (POC) devices for early detection of cancer. Finally, the MCF 7 cancer cells were treated with doxorubicin anti-cancer drug and our device detect the trace amount of MCF 7 based on their electrochemical activity.

    更新日期:2018-05-15
  • Multiplexed antibody detection from blood sera by immobilization of in vitro expressed antigens and label-free readout via imaging reflectometric interferometry (iRIf)
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-12
    Julian Bender, Sabine Bognar, Maurizio Camagna, Julia A.M. Donauer, Julian W. Eble, Ramona Emig, Sabrina Fischer, Rabea Jesser, Luisa Keilholz, Daniel M.U. Kokotek, Julika Neumann, Simon Nicklaus, Ricardo R.Q.P.T. Oude Weernink, Lara G. Stühn, Nathalie Wössner, Stefan D. Krämer, Philipp Schwenk, Nicole Gensch, Günter Roth, Maximilian H. Ulbrich

    The detection of antibodies from blood sera is crucial for diagnostic purposes. Miniaturized protein assays in combination with microfluidic setups hold great potential by enabling automated handling and multiplexed analyses. Yet, the separate expression, purification, and storage of many individual proteins are time consuming and limit applicability. In vitro cell-free expression has been proposed as an alternative procedure for the generation of protein assays. We report the successful in vitro expression of different model proteins from DNA templates with an optimized expression mix. His10-tagged proteins were specifically captured and immobilized on a Ni-NTA coated sensor surface directly from the in vitro expression mix. Finally, the specific binding of antibodies from rabbit-derived blood sera to the immobilized proteins was monitored by imaging reflectometric interferometry (iRIf). Antibodies in the blood sera could be identified by binding to the respective epitopes with minimal cross reactivity. The results show the potential of in vitro expression and label-free detection for binding assays in general and diagnostic purposes in specific.

    更新日期:2018-05-12
  • Recent Technological Advancements in Tuberculosis Diagnostics- A Review
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-11
    Shagun Gupta, Vipan Kakkar

    Early diagnosis and on-time effective treatment are indispensable for Tuberculosis (TB) control - a life threatening infectious communicable disease. The conventional techniques for diagnosing TB normally take two to three weeks. This delay in diagnosis and further increase in detection complexity due to the emerging risks of XDR-TB (Extensively drug Resistant-TB) and MDR-TB (Multidrug Resistant-TB) are evoking interest of researchers in the field of developing rapid TB detection techniques such as biosensing and other point-of-care (POC) techniques. Biosensing technologies along with the collaboration with nanotechnology have enormous potential to boost the MTB detection and for overall management in clinical diagnosis. A diverse range of portable, sensitive and rapid biosensors based on different signal transducer principles and with different biomarkers detection capabilities have been developed for TB detection in the early stages. Further, a lot of progress has been achieved over the years in developing various point-of-care diagnostic tools including non-molecular methods and molecular techniques. The objective of this study is to present a succinct review of the available TB detection techniques that are either in use or under development. The focus of this review is on the current developments occurred in nano-biosensing technologies. A synopsis of ameliorations in different non-molecular diagnostic tools and progress in the field of molecular techniques along with the role of emerging Lab-on-Chip technology for diagnosing and mitigating the TB consequences have also been presented.

    更新日期:2018-05-11
  • Detection of plasma MMP-9 within minutes. Unveiling some of the clues to develop fast and simple electrochemical magneto-immunosensors
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-11
    Gisela Ruiz-Vega, Alicia García-Robaina, Manel Ben Ismail, Helena Passamar, Teresa Garcia-Berrocoso, Joan Montaner, Mohammed Zourob, Ali Othmane, F. Javier del Campo, Eva Baldrich

    Magnetic beads (MB) have been extensively used to produce sensitive and efficient electrochemical magneto-immunosensors. However, MB effective handling requires training, and MB washing after each incubation step is time consuming and contributes to raise result variability. Consequently, most of the electrochemical magneto-immunosensors reported to date, which entailed relatively long and complex multi-step procedures, would be difficult to carry out at point-of-care (POC) settings or by laypersons. For this reason, here we targeted the development of a simplified detection path, which is fast and simple enough to be operated at a POC setting, sufficiently efficient to provide analyte quantitation comparable to classical diagnostic methods, and dependant on minimal technical requirements to facilitate method global exploitation. As a proof-of-concept, we optimized an extremely simple, fast and efficient electrochemical magneto-immunosensor for detection of matrix metalloproteinase 9 (MMP-9). To accomplish this, we optimized MB immunomodification, produced an immunomodified Poly-HRP signal amplifier, developed a single-step magneto-immunoassay, and optimized electrochemical detection using a multiplexed magnetic holder and a ready-to-use commercial substrate solution. The sensor was finally calibrated by detecting MMP-9 in clinical samples. This electrochemical magneto-immunosensor detected MMP-9 in just 12–15 min, displaying linear response between 0.03 and 2 ng·mL−1 of MMP-9, limits of detection (LOD) and quantification (LOQ) of 13 pg·mL−1 and 70 pg·mL−1, respectively, %CV<6%, and accurate quantification of MMP-9 in patient plasma samples. These results were comparable to those afforded by a 5-h reference ELISA that used the same antibodies, confirming the applicability of our simplified method.

    更新日期:2018-05-11
  • A Direct Isothermal Amplification System Adapted for Rapid SNP Genotyping of Multifarious Sample Types
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-11
    Xiaonan Liu, Chao Zhang, Mengye Zhao, Kewu Liu, Hang Li, Ningning Li, Linlin Gao, Xuemin Yang, Ting Ma, Juanli Zhu, Wenli Hui, Kai Hua, Yali Cui
    更新日期:2018-05-11
  • Patchy Gold Coated Fe3O4 Nanospheres with Enhanced Catalytic Activity Applied for Paper-based Bipolar Electrode-Electrochemiluminescence Aptasensors
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-10
    Xin Zhang, Ning Bao, Xiliang Luo, Shou-Nian Ding

    In this work, novel multifunctional patchy gold coated Fe3O4 hybrid nanoparticles (PG-Fe3O4 NPs) have been successfully synthesized in aqueous medium via a facile adsorption-reduction method. A rational formation mechanism has been proposed by monitoring the morphological evolution. The PG-Fe3O4 NPs retained the good magnetic property and exhibited excellent catalytical effeciency towards the electrochemical reduction of hydrogen peroxide. Chronoamperometric and amperometric experiments indicated a relatively high catalytic rate constant of 3.13×105 M−1s−1, a high sensitivity of 578.87 µA·mM−1·cm−2 and a low Michaelis-Menten constant of 462 µM. Meanwhile, the introduction of patchy gold could help biofunctionalization via Au-S bond for different biodetection and biosensing purposes. Here, as an example, thiol-terminated aptamers were immobilized onto the patchy gold part as a signal probe to detect carcinoembryonic antigen (CEA). A related paper-based bipolar electrode-electrochemiluminescence (pBPE-ECL) aptasensor was fabricated as the low-cost, disposable and miniature platform. To improve the sensitivity, Au nanodendrites were electrodeposited at the BPE cathode as the matrix for Apt1 immobilization. This aptasensor showed a wide linear range of 0.1 pg mL−1–15 ng mL−1 with a low detection limit of 0.03 pg mL−1, remaining competitive against other ones, and also demonstrating the PG-Fe3O4 NPs have promising potential for catalysis and bioassays.

    更新日期:2018-05-10
  • Biomimetic Magnetoelectric Nanocrystals Synthesized by Polymerization of Heme as Advanced Nanomaterials for Biosensing Application
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-10
    Jeong Eun Hyeon, Da Woon Jeong, Young Jin Ko, Seung Wook Kim, Chulhwan Park, Sung Ok Han
    更新日期:2018-05-10
  • 更新日期:2018-05-10
  • Dual-core all-fiber integrated immunosensor for detection of protein antigens
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-09
    Karol Wysokiński, Dawid Budnicki, Janusz Fidelus, Łukasz Szostkiewicz, Łukasz Ostrowski, Micha Murawski, Marcin Staniszewski, Magdalena Staniszewska, Marek Napierała, Tomasz Nasiłowski

    An optical fiber interferometric microprobe for detection of specific proteins is presented in this paper. The microprobe is an all-fiber device, which is based on Michelson interferometer configuration, which allows for detection of protein antigens in an analyzed solution thanks to antibodies immobilized on the sensor surface. The interferometer is made of dual core fiber and has a precisely formed arm length difference, achieved by splicing a fragment of polarization maintaining fiber to one of the cores. An all-fiber configuration of the sensor decreases substantially cross-sensitivities to temperature and deformation in comparison to other optical fiber interferometers. Reported sensor has a sensing region on the tip of the interferometer and therefore may be used for point measurements in medicine. The immunosensor and optical measuring system are designed to utilize the most common broadband light sources that operate at a central wavelength of 1.55 μm. The results show that it is possible to detect a protein antigen present in a solution by using an all-fiber interferometer coated with specific antibodies. The resulting peak shift can reaches 0.6 nm, which is sufficient to be measured by an optical spectrum analyzer or a spectrometer. A model allowing for estimation of the value of lower limit of detection for such sensors has been elaborated. The elaborated detection system may act as a framework for detection of various antigens and thus it can find future applications in medical diagnostics.

    更新日期:2018-05-09
  • An ultrasensitive and selective electrochemical aptasensor based on rGO-MWCNTs/Chitosan/carbon quantum dot for the detection of lysozyme
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-09
    Behzad Rezaei, Hamid Reza Jamei, Ali Asghar Ensafi

    An aptamer-based method is described for the electrochemical determination of lysozyme. A glassy carbon electrode was modified with a nanocomposite composed of reduced graphene oxide (rGO), multi-walled carbon nanotubes (MWCNTs), chitosan (CS), and a synthesized carbon quantum dot (CQD) from CS. The composition of the nanocomposite (rGO-MWCNT/CS/CQD) warrants a high surface-to-volume ratio, high conductivity, high stability, and great electrocatalytic activity. This nanocomposite provides a suitable site for better immobilization of aptamers due to the existence of many amino and carboxyl functional groups, and remaining oxygen-related defects properties in rGO. In addition, this nanocomposite allows considerable enhancement of the electrochemical signal and contributes to improving sensitivity. The amino-linked lysozyme aptamers were immobilized on the nanocomposite through covalent coupling between the amino groups of the aptamer and the amino groups of the nanocomposite using glutaraldehyde (GLA) linker. The modified electrode was characterized by electrochemical methods including differential pulse voltammetry (DPV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). In the presence of lysozyme, the immobilized aptamer selectively caught the target lysozyme on the electrode interface that leads to a decrease in the DPV peak current and an increase in Charge Transfer Resistance (Rct) in EIS as an analytical signal. Using the obtained data from DPV and EIS techniques, two calibration curves were drawn. The anti-lysozyme aptasensor proposed has two very low LODs. These measures are 3.7 and 1.9 fmol L−1 within the wide detection ranges of 20 fmol L−1 to 10 nmol L−1, and 10 fmol L−1 to 100 nmol L−1 for DPV and EIS calibration curves, respectively. The GCE/rGO-MWCNT/CS/CQD showed sensitivity, high reproducibility, specificity and rapid response for lysozyme which can be used in biomedical fields.

    更新日期:2018-05-09
  • Plasmonic Colorimetric Sensors Based on Etching and Growth of Noble Metal Nanoparticles: Strategies and Applications
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-09
    Zhiyang Zhang, Han Wang, Zhaopeng Chen, Xiaoyan Wang, Jaebum Choo, Lingxin Chen
    更新日期:2018-05-09
  • A signal-decreased electrochemical immunosensor for the sensitive detection of LAG-3 protein based on a hollow nanobox-MOFs/AuPt alloy
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-08
    Wei Xu, Zhen Qin, Yutong Hao, Qiang He, Shuai Chen, Zhongshuang Zhang, Dan Peng, Haiyan Wen, Jun Chen, Jingfu Qiu, Chaorui Li
    更新日期:2018-05-09
  • A simple ultrasensitive electrochemical sensor for simultaneous determination of gallic acid and uric acid in human urine and fruit juices based on zirconia-Choline chloride-gold nanoparticles-modified carbon paste electrode
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-08
    Seyed Alireza Shahamirifard, Mehrorang Ghaedi, Zahra Razmi, Shaaker Hajati

    The determination of gallic acid (GA) and uric acid (UA) is essential due to their biological properties. Numerous methods have been reported for the analysis of GA and UA in various real samples. However, the development of a simple, rapid and practical sensor still remains a great challenge. Here, a carbon paste electrode (CPE) was modified by nanocomposite containing zirconia nanoparticles (ZrO2NPs), Choline chloride (ChCl) and gold nanoparticles (AuNPs) to construct ZrO2-ChCl-AuNPs/CPE as electrochemical sensor for the simultaneous electro-oxidation of GA and UA. Characterization was performed by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The modified electrode was investigated by different methods including electrochemical impedance spectroscopy and cyclic voltammetry. Kinetic parameters such as charge transfer coefficient, standard heterogeneous electron transfer rate constant and other parameters were calculated via voltammetry techniques. Differential pulse voltammetry was used for simultaneous determination of GA and UA applying the ZrO2-ChCl-AuNPs/CPE electrode. At the optimum conditions, this sensor showed a linear response in the ranges 0.22– 55 and 0.12–55 µM for GA and UA, respectively. In addition, low detection limits of 25 and 15 nM were obtained for GA and UA, respectively. Furthermore, ZrO2-ChCl-AuNPs/CPE was successfully applied for the independent determination of GA in green tea and fruit juice as well as the simultaneous determination of GA and UA in human urine samples.

    更新日期:2018-05-09
  • An Ultrasensitive Electrochemiluminescence Biosensor for Detection of MicroRNA by in-situ Electrochemically Generated Copper Nanoclusters as Luminophore and TiO2 as Coreaction Accelerator
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-08
    Hongxia Liao, Ying Zhou, Yaqin Chai, Ruo Yuan

    Herin, we constructed an ultrasensitive electrochemiluminescence (ECL) biosensor for detecting microRNA-21 (miR-21) based on in-situ generation of copper nanoclusters (Cu NCs) as luminophore and titanium dioxide (TiO2) as coreaction accelerator. First, numerous AT-rich double-stranded DNA (dsDNA) was produced from the conversion of a small amount of target miR-21 via the combination of exonuclease III (Exo III)-assisted amplification and hybridization chain reaction (HCR), which could reduce the aggregation-caused self-etching effect of Cu NCs and improve the emitting of Cu NCs. Simultaneously, the introduction of TiO2 in the sensing interface not just acted as the immobilizer of dsDNA-stabilized Cu NCs, more than acted as the coreaction accelerator to accelerate the reduction of the coreaction reagent (S2O82−) for significantly enhancing the ECL efficiency of Cu NCs. The biosensor showed an excellent linear relationship in the concentration range from 100 aM to 100 pM with the detection limit of 19.05 aM. Impressively, the strategy not only opened up a novel and efficient preparation method for the Cu NCs, but expanded the application of Cu NCs in ultrasensitive biodetection owing to the addition of coreaction accelerator.

    更新日期:2018-05-09
  • A wavelength-modulated localized surface plasmon resonance (LSPR) optical fiber sensor for sensitive detection of mercury(II) ion by gold nanoparticles-DNA conjugates
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-08
    Shuo Jia, Chao Bian, Jizhou Sun, Jianhua Tong, Shanhong Xia

    The study presented herein invesetigated an easy preparation, high performance, wavelength-modulated LSPR optical fiber chemosensor coated by gold nanospheres(AuNS) for Hg2+ detection based on thymine-Hg2+-thymine base pair mismatches and the coupled plasmonic resonance effect.Utilizing electrostatic self-assembly method, the high density and despersivity monolayer AuNS coated LSPR fiber sensor had the near field refractive index sensitivity up to 2016 nm/RIU. The single-strand probe DNA served as a binding element for free AuNS labelled-target DNA conjugates was attached to the monolayer AuNS by Au-S bond. In the present of Hg2+, the coupled plasmonic resonance band between monolayer AuNS and free AuNS was produced by thymine-Hg2+-thymine structure and leaded to red-shift of LSPR peak. Under the optimal conditions, the enlarged red-shift in peak of LSPR spectroscopy was linearly with the concentration of Hg2+ in the range from 1.0×10−9 to 5.0×10−8 M with the coefficient of 0.976. The limit of detection was 0.7 nM(S/N=3). The specificity of the sensor was proved high by evaluating the response to other heavy metal ions. The proposed fiber sensor provided a label-free, miniature, low-cost approach for the Hg2+ detection and had potential in real environmental evaluations.

    更新日期:2018-05-08
  • Dual-wavebands-resolved electrochemiluminescence multiplexing immunoassay with dichroic mirror assistant photomultiplier-tubes as detectors
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-05
    Fang Zhang, Yupeng He, Kena Fu, Li Fu, Bin Zhang, Huaisheng Wang, Guizheng Zou

    A dual-wavebands-resolved electrochemiluminescence (ECL) multiplexing immunoassay (MIA) was developed for simultaneously detecting alpha fetoprotein antigen (AFP) in greenish waveband with CdSe550 (λmax = 550 nm) nanocrystals (NCs) and cancer antigen 125 (CA125) in near-infrared waveband with CdTe790 (λmax = 790 nm) NCs via one-pot ECL reaction, in which dichroic mirror works as a key part to reflect ECL from CdSe550 to one photomultiplier-tube (PMT) and transmit ECL from CdTe790 to the other PMT for dual-wavebands-resolved assay. The proposed ECL-MIA strategy was capable of simultaneously determining AFP with linearly response from 5 pg/mL to 5 ng/mL and limit of detection at 1 pg/mL, and CA125 with linearly response from 5 mU/mL to 1 U/mL and limit of detection at 1 mU/mL, with desired specificity and without obvious energy-transfer between ECL tags. The dichroic mirror assistant ECL setup is easy-to-assemble and convenient for the popularization of color-resolved multiplexing ECL assay.

    更新日期:2018-05-05
  • Mannosyl Electrochemical Impedance Cytosensor for Label-Free MDA-MB-231 Cancer Cell Detection
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-05
    Yi-Hsuan Tang, Han-Chen Lin, Chiao-Ling Lai, Po-Yu Chen, Chian-Hui Lai

    A label-free and ultrasensitive electrochemical impedance cytosensor was developed to specifically detect the breast cancer cells MDA-MB-231 via the interaction between the mannosyl glassy carbon electrode (GCE) and the overexpressed mannose receptors on the target cell surface. The mannosyl GCE was prepared through electrografting of the amino-functionalized mannose derivatives on GCE surface in which a covalent bond was formed between carbon of the electrode and the amino group of the mannose derivative. The fluorescent microscopy indicated that the electrode is specific for MDA-MB-231 cells, with good biocompatibility for viable captured cells. The derivative with a shorter alkyl linker, mannose-C2NH2, showed a better sensitivity than that with a longer linker, mannose-C6NH2. GCE modified with amino-functionalized galactose derivative, galactose-C2NH2, shows no function to the detection of MDA-MB-231 cells. The specific interaction between the mannosyl GCE and Con A (a mannose-binding lectin) or MDA-MB-231 breast cancer cells with overexpressed mannose receptors was determined through the change of peak separation in the cyclic voltammogram or the change of charge transfer resistance in the electrochemical impedance spectra (Nyquist plot) in the electrolytes containing a reversible redox couple [Fe(CN)6]3−/[Fe(CN)6]4−. The charge transfer resistance in the Nyquist plots linearly depended on the concentration of MDA-MB-231 cells (1.0 × 10 to 1.0 × 105 cells mL−1, with 10 cells mL−1 being the lower detection limit). Introducing 0.1% polyethylene glycol-200 (PEG-200) was able to prevent the interference caused by 1.0 × 103 HEK-293T cells mL−1, a non-cancer cell line (control).

    更新日期:2018-05-05
  • Detection of PARP-1 Activity based on Hyperbranched-Poly (ADP-ribose) Polymers Responsive Current in Artificial Nanochannels
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-04
    Yong Liu, Jiahui Fan, Haitang Yang, Ensheng Xu, Wei Wei, Yuanjian Zhang, Songqin Liu

    The cellular enzyme poly ADP (ADP: adenosine diphosphate)-ribose polymerase-1 (PARP-1) plays key roles in DNA repair. Its activity is closely related to various cancer developments. Detection of PARP-1 activity is significant, however, it is relatively difficult since it lacks superiority property that can be used to detect conveniently. PARP-1 lead to the synthesis of hyperbranched poly (ADP-ribose) polymers (PAR) using nicotinamide adenine dinucleotide (NAD+) as substrate during DNA damage repairing. In this paper, we found that hyper-branched PAR increased the steric hindrance and reduced the flux of probe ions effectively in anodic aluminum oxide (AAO) nanochannels. To the best of our knowledge, few papers have been reported that hyper-branched polymer has the similar effects in nanochannels as G-quadruplex DNA. Thus, a novel and simple strategy for PARP-1 detection has been proposed due to its great impacts on the diffusion flux of ferricyanide in AAO. It is also proved that electrostatic repulsion is another important factor to influence the current. The method is label-free, simple and sensitive. Quantitative detection of PARP-1 activity was achieved with the detection limit of 0.006 U, which is lower or comparable to the most reported methods. The method has good accuracy and reproducibility. The strategy has been used to detect PARP-1 activity in real breast cancer cells and to evaluate PARP-1 inhibitors with satisfactory results, indicating that it is a potential powerful tool for clinical diagnosis and drug development in the future.

    更新日期:2018-05-04
  • Novel Electrochemical Sensing Platform for Ultrasensitive Detection of Cardiac Troponin I Based on Aptamer-MoS2 Nanoconjugates
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-04
    Xiujuan Qiao, Kunxia Li, Jinqiong Xu, Ni Cheng, Qinglin Sheng, Wei Cao, Tianli Yue, Jianbin Zheng

    Cardiac troponin I (cTnI) is a specific and sensitive biomarker for the early diagnosis of acute myocardial infarction and for the subsequent clinical treatments. In this work, novel electrochemical sensing platform for sensing of cTnI based on aptamer-MoS2 nanoconjugates was proposed. For comparison, core-shell Au@SiO2@Au nanoparticles were also used for sensing of cTnI. The sensing schemes and electrochemical responses of the proposed sensors were investigated by electrochemical impedance spectroscopy (EIS) in 5.0 mM K3[Fe(CN)6]/K4[Fe(CN)6] (1:1) solution containing 0.1 M KCl, respectively. Results showed that the aptamer-Au@SiO2@Au based aptasensor shows a linear rage of 10 pM-10.0 μM with the detection limits of 1.23 pM. For the aptamer-MoS2 nanosheets based aptasensor, the linear range for cTnI detection was from 10 pM to 1.0 μM with a lower detection limit of 0.95 pM. Meanwhile, both the sensors were successfully applied for detection of cTnI in human blood samples. The two kinds of aptsensors have been successfully used for detecting of cTnI in human blood serums. Moreover, no negligible signal changes could be observed in the presence of non-targets of CK-MB and Myo, suggesting the good potential for clinic diagnosis.

    更新日期:2018-05-04
  • Improved sensitivity and limit-of-detection of lateral flow devices using spatial constrictions of the flow-path
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-03
    Ioannis N. Katis, Peijun J.W. He, Robert W. Eason, Collin L. Sones

    We report on the use of a laser-direct write (LDW) technique that allows the fabrication of lateral flow devices with enhanced sensitivity and limit of detection. This manufacturing technique comprises the dispensing of a liquid photopolymer at specific regions of a nitrocellulose membrane and its subsequent photopolymerisation to create impermeable walls inside the volume of the membrane. These polymerised structures are intentionally designed to create fluidic channels which are constricted over a specific length that spans the test zone within which the sample interacts with pre-deposited reagents. Experiments were conducted to show how these constrictions alter the fluid flow rate and the test zone area within the constricted channel geometries. The slower flow rate and smaller test zone area result in the increased sensitivity and lowered limit of detection for these devices. We have quantified these via the improved performance of a C-Reactive Protein (CRP) sandwich assay on our lateral flow devices with constricted flow paths which demonstrate an improvement in its sensitivity by 62× and in its limit of detection by 30× when compared to a standard lateral flow CRP device.

    更新日期:2018-05-03
  • Sensitive and Label-free Electrochemical Lead Ion Biosensor based on a DNAzyme triggered G-quadruplex/hemin conformation
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-02
    LeLe Wang, Yanli Wen, Lanying Li, Xue Yang, Nengqin Jia, Wen Li, Jiaoran Meng, Manlei Duan, Xiaoguang Sun, Gang Liu

    Lead ion (Pb2+) is a common environmental contaminant, which causes serious bioaccumulation and toxicity in human body. In this work, we developed a novel Pb2+ electrochemical biosensor using the specific DNAzyme on a DNA tetrahedron probe, in the presence of Pb2+, the substrate strand was cleaved into two parts and released a “G-rich” oligo which subsequently formed a G-quadruplex/hemin complex, generating a detectable catalysis current signal with the assistant of H2O2. The 3-D DNA tetrahedron regulated the density and orientation of the probe and thus improved the DNAzyme reaction, and facilitated the complex DNA conformational change in the confined space of the interface on the electrode surface, Finally, the LOD of our biosensor was proved to be 0.008 nM (3σ), which is 9000 times lower than the safety limit of EPA (15 μg/L or 72 nM), and 6000 times lower than IARC (10 μg/L or 48.26 nM), and more importantly, the specificity and reproducibility of the proposed biosensor was well demonstrated.

    更新日期:2018-05-03
  • Monitoring of early diagnosis of Alzheimer's disease using the cellular prion protein and poly(pyrrole-2-carboxylic acid) modified electrode
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-01
    Jieling Qin, Dong Gyu Jo, Misuk Cho, Youngkwan Lee

    Amyloid-beta oligomers (AβΟ) are considered to be reliable biomarkers for the diagnosis of Alzheimer’ disease (AD), and the cellular prion protein (PrPC) is identified as a receptor for AβO. We demonstrated a label and antibody-free electrochemical biosensor for the selective detection of AβO using an electrically conductive poly(pyrrole-2-carboxylic acid) (PPyCOOH) linking agent and PrPC receptor. In the fabrication of the biosensor, each step was characterized by electrochemical impedance spectroscopy and cyclic voltammetry. The developed PrPc/PPyCOOH biosensor exhibited extremely low detection limit of 10−4 pM with high sensitivity which is desirable for the early diagnosis of AD. The sensing performance was further confirmed by the mice infected with AD. The proposed sensor emerged as a promising tool for the early detection of AβO.

    更新日期:2018-05-02
  • Double Determination of Long Noncoding RNAs from Lung Cancer via Multi-amplified Electrochemical Genosensor at Sub-femtomole Level
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-02
    Xiaoyan Li, Gang Peng, Feng Cui, Qianying Qiu, Xiaojun Chen, He Huang

    An ultrasensitive electrochemical genosensor has been fabricated for the double determination of two different specific sequences deduced from the maternally expressed gene3 (MEG3) lncRNA (long noncoding RNA), which was demonstrated by coupling RNase A-aided target recycling with DNA supersandwich-induced signal enhancement, based on a composite interface of graphene-like tungsten disulfide/dendritic gold nanostructures (WS2/DGN). Firstly, duple target sequences of T1 and T2 were captured by the primer probes of P1/P2 functionalized Fe3O4@C magnetic nanoparticles, via the DNA/RNA hybridization between T1/T2 and P1/P2. In the presence of RNase A, T1 and T2 were released to trigger the target recycling, accompanied by the generation of numerous intermediate DNAs designated as IT1 and IT2, respectively. After the magnetic separation, the IT1 and IT2 were liberated and hybridized with the capture probes of CP1/CP2 loaded DGN/WS2 modified electrode. Subsequently, the stepwise DNA hybridization chain reactions (HCR) labeled with ferrocene (Fc) and methyleneblue (MB) were processed, respectively. The DPV current values of Fc and MB were recorded, which were proportional with the concentration of T1 and T2, respectively. Using the multiple amplification strategy, this newly designed genosensor provided a wide linear range from 1 fM to 100 pM with a low detection limit of 0.25 fM for T1 and 0.3 fM for T2. The application of the genosensor in real serum sample has also been studied, confirming the excellent selectivity and sensitivity for the application in bioanalysis and clinical diagnostics.

    更新日期:2018-05-02
  • Label-free nano-biosensing on the road to tuberculosis detection
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-01
    Behrouz Golichenari, Kelly Velonia, Rahim Nosrati, Alireza Nezami, Aref Farokhi-Fard, Khalil Abnous, Javad Behravan, Aristidis M. Tsatsakis

    Tuberculosis, an ailment caused by the bacterium Mycobacterium tuberculosis (Mtb) complex, is one of the catastrophic transmittable diseases that affect human. Reports published by WHO indicate that in 2017 about 6.3 million people progressed to TB and 53 million TB patients died from 2000 to 2016. Therefore, early diagnosis of the disease is of great importance for global health care programs. Common diagnostics like the traditional PPD test and antibody-assisted assays suffer the lack of sensitivity, long processing time and cumbersome post-test proceedings. These shortcomings restrict their use and encourage innovations in TB diagnostics. In recent years, the biosensor concept opened up new horizons in sensitive and fast detection of the disease, reducing the interval time between sampling and diagnostic result. Among new diagnostics, label-free nano-biosensors are highly promising for sensitive and accessible detection of tuberculosis. Various specific label-free nano-biosensors have been recently reported detecting the whole cell of M. tuberculosis, mycobacterial proteins and IFN-γ as crucial markers in early diagnosis of TB. This article provides a focused overview on nanomaterial-based label-free biosensors for tuberculosis detection.

    更新日期:2018-05-01
  • Biosensor-based selective detection of Zika virus specific antibodies in infected individuals
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-01
    Gustavo Cabral-Miranda, Ana R. Cardoso, Luis CS. Ferreira, M.Goreti F. Sales, Martin F. Bachmann

    Zika virus (ZIKV) recently emerged as a global threat subsequent to its global spread because it induces microencephaly and other brain damages in infants born to infected mothers. Epidemiological monitoring of infection has been hampered by the absence of reliable serological tests capable to distinguish between ZIKV and other Flavivirus infections, in particular Dengue virus (DENV). As both viruses are transmitted by the same mosquitoe-species, their distributions largely overlap and reliable serological distinction between the viruses is essential. Here we develop a novel biosensor which is based on recombinant forms of ZIKV non-structural protein 1 (NS1) and the domain III of the envelope protein (EDIII). Using electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV), we demonstrate that in addition to extremely sensitive detection of ZIKV-specific antibodies in serum and saliva, the biosensor promptly distinguished ZIKV and DENV-specific antibodies. Hence, this novel biosensor allows assessing ZIKV antibodies in blood and saliva and results are unaffected by presence of DENV virus-specific antibodies.

    更新日期:2018-05-01
  • Versatile Graphene Biosensors for Enhancing Human Cell Therapy
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-05-01
    George M. Vlăsceanu, Roxana-Maria Amărandi, Mariana Ioniță, Teddy Tite, Horia Iovu, Luisa Pilan, Jorge S. Burns

    Technological advances in engineering and cell biology stimulate novel approaches for medical treatment, in particular cell-based therapy. The first cell-based gene therapy against cancer was recently approved by the US Food and Drug Administration. Progress in cancer diagnosis includes a blood test detecting five cancer types. Numerous stem cell phase I/II clinical trials showing safety and efficacy will soon pursue qualifying criteria for advanced therapy medicinal products (ATMP), aspiring to join the first stem-cell therapy approved by the European Medicines Agency. Cell based therapy requires extensive preclinical characterisation of biomarkers indicating mechanisms of action crucial to the desired therapeutic effect. Quantitative assays monitoring critical functions for the manufacture of optimal cell and tissue-based clinical products, include successful potency assays for implementation. The challenge to achieve high quality measurement is increasingly met by progress in biosensor design. We adopt a cell therapy perspective to highlight recent examples of graphene-enhanced biointerfaces for measurement of biomarkers relevant to cancer treatment, diagnosis and tissue regeneration. Graphene based biosensor design problems can thwart their use for health care transformative point of care testing and real-time applications. We discuss concerns to be addressed and emerging solutions for establishing clinical grade biosensors to accelerate human cell therapy.

    更新日期:2018-05-01
  • MAGNETIC MULTIWALLED CARBON NANOTUBES AS NANOCARRIER TAGS FOR SENSITIVE DETERMINATION OF FETUIN IN SALIVA
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-30
    Esther Sánchez-Tirado, Araceli González-Cortés, Paloma Yáñez-Sedeño, José M. Pingarrón

    This paper reports the development and performance of an electrochemical immunosensor using magnetic multiwalled carbon nanotubes (m-MWCNTs) as nanocarrier tags for the determination of human fetuin A (HFA), a relevant biomarker of obesity, insulin resistance, and type-2 diabetes as well as for pancreatic and liver cancers and inflammatory processes. Screen-printed carbon electrodes were grafted with p-aminobezoic acid and streptavidin was covalently immobilized on the electrode surface. A biotinylated capture antibody was immobilized through streptavidin-biotin interaction and a sandwich assay configuration was implemented using m-MWCNTs conjugated with HRP and anti-HFA antibodies as the detection label. The determination of HFA was accomplished by measuring the current produced by the electrochemical reduction of benzoquinone at –200 mV upon addition of H2O2 as HRP substrate. The prepared m-MWCNTs were characterized by SEM, TEM, XRD and EDS. All the steps involved in the immunosensor preparation were monitored by electrochemical impedance spectroscopy and cyclic voltammetry. A linear calibration plot for HFA was found between 20 and 2000 pg/mL with a LOD value of 16 pg/mL. This performance is notably better than that reported for an ELISA kit and a chronoimpedimetric immunosensor. The favorable contribution of m-MWCNTs in comparison with MWCNTs without incorporated magnetic particles to this excellent analytical performance is also highlighted. The immunosensor selectivity against other proteins and potentially interfering compounds was excellent. In addition, the usefulness of the immunosensor was demonstrated by the analysis of HFA in saliva with minimal sample treatment.

    更新日期:2018-04-30
  • Triggering the Electrolyte-Gated Organic Field-Effect Transistor output characteristics through gate functionalization using diazonium chemistry: Application to biodetection of 2,4-dichlorophenoxyacetic acid
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-26
    T.T.K. Nguyen, T.N. Nguyen, G. Anquetin, S. Reisberg, V. Noël, G. Mattana, J. Touzeau, F. Barbault, M.C. Pham, B. Piro

    We investigated an Electrolyte-Gated Organic Field-Effect transistor based on poly(N-alkyldiketopyrrolo-pyrrole dithienylthieno[3,2-b]thiophene) as organic semiconductor whose gate electrode was functionalized by electrografting a functional diazonium salt capable to bind an antibody specific to 2,4-dichlorophenoxyacetic acid (2,4-D), an herbicide well-known to be a soil and water pollutant. Molecular docking computations were performed to design the functional diazonium salt to rationalize the antibody capture on the gate surface. Sensing of 2,4-D was performed through a displacement immunoassay. The limit of detection was estimated at around 2.5 fM.

    更新日期:2018-04-27
  • Ubiquinone modified printed carbon electrodes for cell culture pH monitoring
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-26
    Craig McBeth, Rajaa Al Dughaishi, Andrew Paterson, Duncan Sharp

    The measurement of pH is important throughout many biological systems, but there are limited available technologies to enable its periodical monitoring in the complex, small volume, media often used in cell culture experiments across a range of disciplines. Herein, pad printed electrodes are developed and characterised through modification with: a commercially available fullerene multiwall carbon nanotube composite applied in Nafion, casting of hydrophobic ubiquinone as a pH probe to provide the electrochemical signal, and coated in Polyethylene glycol to reduce fouling and potentially enhance biocompatibility, which together are proven to enable the determination of pH in cell culture media containing serum. The ubiquinone oxidation peak position (Epa) provided an indirect marker of pH across the applicable range of pH 6 – 9 (R2=0.9985, n=15) in complete DMEM. The electrochemical behaviour of these sensors was also proven to be robust; retaining their ability to measure pH in cell culture media supplemented with serum up to 20% (v/v) [encompassing the range commonly employed in cell culture], cycled >100 times in 10% serum containing media and maintain >60% functionality after 5 day incubation in a 10% serum containing medium. Overall, this proof of concept research highlights the potential applicability of this, or similar, electrochemical approaches to enable to detection or monitoring of pH in complex cell culture media.

    更新日期:2018-04-26
  • Construction Of Conducting Polymer/Cytochrome C/Thylakoid Membrane Based Photo-bioelectrochemical Fuel Cells Generating High Photocurrent Via Photosynthesis
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-26
    Emre Cevik, Buket Bezgin Carbas, Mehmet Senel, Huseyin Bekir Yildiz

    In this study, a photo-bioelectrochemical fuel cell was constructed for photocurrent generation by illuminating the electrodes within an aqueous solution. In this purpose, gold electrode was coated with poly 4-(4H-Dithieno [3,2-b:2’,3’-d]pyrol-4-yl) aniline, P(DTP-Ph-NH2) conductive polymer film by using electrochemical polymerization. Then, P(DTP-Ph-NH2) conductive polymer film coated surface was electrochemically modified with cytochrome C which covalently linked onto the surface via bis-aniline functionality of the polymer film and formed crosslinked-structure.The thylakoid membrane was attached on the surface of this electrode by using bissulfosaxinimidyl suberate (BS3) and used as photo-anode in photo-bioelectrochemical fuel cell. The photo-cathode of the photo-bioelectrochemical fuel cell fabrication was followed by the modification of conductive polymer poly[5-(4H-dithieno [3,2-b:2’,3’-d]pyrol-4-yl) naphtalene-1-amine] film coating, glutaraldehyde activation, and bilirubin oxidase enzyme immobilization. During the photosynthesis occurring in thylakoid membrane under the light, water was oxidized and separated; while oxygen was released in anode side, the cathode side was reduced the oxygen gas into the water via a bio-electro-catalytic method. The cytochrome C was used for binding of thylakoid membrane to the electrode surface and play an important role for transferring of electrons released as a result of photosynthesis.

    更新日期:2018-04-26
  • Bimetallic NiFe oxide structures derived from hollow NiFe Prussian blue nanobox for label-free electrochemical biosensing adenosine triphosphate
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-24
    Minghua Wang, Longyu Yang, Bin Hu, Jiameng Liu, Linghao He, Qiaojuan Jia, Yingpan Song, Zhihong Zhang

    We designed and constructed a novel aptasensor based on the porous nanostructured bimetallic NiFe-oxides embedded with the mesoporous carbon (represented by NiOxFeOy@mC) for sensitively detecting adenosine triphosphate (ATP), of which the porous NiOxFeOy@mC was derived from the hollow NiFe Prussian blue analogue (hollow NiFe PBA) by calcinating under high temperature. Owning to the excellent electrochemical activity originated from the metal oxides and mesoporous carbon and the strong binding interaction between the aptamer strands and the nanostructure hybrid, the formed porous NiOxFeOy@mC composite calcinated at 900 °C exhibited superior sensitivity toward ATP determination in comparison with other porous nanocubes obtained at 500 and 700 °C. The proposed aptasensor not only revealed a wide linear range from 5.0 fg·mL−1 to 5.0 ng·mL−1 with a extremely low detection limit of 0.98 fg·mL−1 (1.62 fM) (S/N=3), but also displayed high selectivity towards other interferences, good stability and reproducibility, and acceptable applicability. Therefore, this proposed approach provides a promising platform for ultra-sensitive detection of ATP, further having the potential applications on diagnosis of ATP-related diseases.

    更新日期:2018-04-25
  • A cascade autocatalytic strand displacement amplification and hybridization chain reaction event for label-free and ultrasensitive electrochemical nucleic acid biosensing
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-23
    Zhiqiang Chen, Ying Liu, Chen Xin, Jikuan Zhao, Shufeng Liu

    Herein, an autocatalytic strand displacement amplification (ASDA) strategy was proposed for the first time, which was further ingeniously coupled with hybridization chain reaction (HCR) event for the isothermal, label-free and multiple amplification toward nucleic acid detection. During the ASDA module, the target recognition opens the immobilized hairpin probe (IP) and initiates the annealing of the auxiliary DNA strand (AS) with the opened IP for the successive polymerization and nicking reaction in the presence of DNA polymerase and nicking endonuclease. This induces the target recycling and generation of a large amount of intermediate DNA sequences, which can be used as target analogy to execute the autocatalytic strand displacement amplification. Simultaneously, the introduced AS strand can propagate the HCR between two hairpins (H1 and H2) to form a linear DNA concatamer with cytosine (C)-rich loop region, which can facilitate the in-situ synthesis of silver nanoclusters (AgNCs) as electrochemical tags for further amplification toward target responses. With current cascade ASDA and HCR strategy, the detection of target DNA could be achieved with a low detection limit of about 0.16 fM and a good selectivity. The developed biosensor also exhibits the distinct advantages of flexibility and simplicity in probe design and biosensor fabrication, and label-free electrochemical detection, thus opens a promising avenue for the detection of nucleic acid with low abundance in bioanalysis and clinical biomedicine.

    更新日期:2018-04-25
  • Electrochemical immunosensor for differential diagnostic of Wuchereria Bancrofti using a synthetic peptide
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-22
    Isis C. Prado, Verônica G. Mendes, André L.A. Souza, Rosa. F. Dutra, Salvatore G. De-Simone

    Lymphatic filariasis (LF) is a neglected tropical disease transmitted by mosquitoes and the second cause of permanent disability leading to a significant morbidity and mortality rate. Previously, we have identified epitopes of the filarial abundant larval transcript-2 (ALT-2) protein using a microarray mapping. In this study, one of the epitopes (Wb/ALT2-A5) was used to construct an electrochemical immunosensor. Electrochemical technique of cyclic voltammetry was performed for detecting the signal generated by the interaction between the (Wb/ALT2-A5) peptide and circulating antibodies of serum human samples. (Wb/ALT2-A5) epitope antigens were successfully immobilized on the working electrode of a screen-printed carbon electrode (SPCE) by their amine groups via chitosan film by coupling with glutaraldehyde as crosslinker. After the sensor ready, a pool of human sera infected with Wuchereria bancrofti was added to its surface. Electrochemical responses were generated by applying a potential of −0.6 to 0.6 V, scan rate of 0.025 V/s. A detection limit of 5.0 µg mL−1 for the synthetic peptides (Wb/ALT2-A5) and 0.002 µg mL−1 for human serum, with a sensitivity of 1.86 µA. The performance of this assay was successfully tested in human serum samples from infected and healthy patients. Thus, this proposed immunosensor, which is able to identify circulating antibodies, can be applied to the diagnosis of the W. bancrofti parasitic disease.

    更新日期:2018-04-25
  • Rapid and background-free detection of avian influenza virus in opaque sample using NIR-to-NIR upconversion nanoparticle-based lateral flow immunoassay platform
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-22
    Jaeyoung Kim, Jung Hoon Kwon, Jinyoung Jang, Hyojin Lee, Seungki Kim, Young Ki Hahn, Sang Kyung Kim, Kwan Hyi Lee, Seok Lee, Heesoo Pyo, Chang-Seon Song, Joonseok Lee

    Rapid and sensitive on-site detection of avian influenza virus (AIV) is the key for achieving near real-time surveillance of AIV and reducing the risk of dissemination. However, unlike the laboratory-prepared transparent buffer solutions containing a single type of influenza virus, distinction between real- and false- positive outputs and detection of low concentrations of AIV in stool specimens or cloacal swabs are difficult. Here, we developed a rapid and background-free lateral flow immunoassay (LFA) platform that utilizes near-infrared (NIR)-to-NIR upconversion nanoparticles (UCNPs) to yield a sensor that detects AIV nucleoproteins (NPs) from clinical samples within 20 minutes. Ca2+ as a heterogeneous dopant ion in the shell enhanced the NIR-to-NIR upconversion photoluminescence (PL) emission without inducing significant changes in the morphology of the UCNPs. In a mixture of opaque stool samples and gold nanoparticles (GNPs), which are components of commercial AIV LFA, the background signal of the stool samples masked the absorption peak of GNPs. However, UCNPs dispersed in the stool samples still show strong emission centered at 800 nm when excited at 980 nm, which enables the NIR-to-NIR upconversion nanoparticle-based lateral flow immunoassay (NNLFA) platform to detect 10-times lower viral load than a commercial GNP-based AIV LFA. The detection limit of NNLFA for LPAI H5N2 and HPAI H5N6 viruses was 102 and 103.5 EID50/mL, respectively. Moreover, the viruses were successfully detected within dark brown-colored samples using the NNLFA but not the commercial AIV LFA. Therefore, the rapid and background-free NNLFA platform can be used for sensitive on-site detection of AIV.

    更新日期:2018-04-25
  • Recent advances on aptamer-based biosensors to detection of platelet-derived growth factor
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-22
    Nasrin Razmi, Behzad Baradaran, Maryam Hejazi, Mohammad Hasanzadeh, Jafar Mosafer, Ahad Mokhtarzadeh, Miguel de la Guardia

    Platelet-derived growth factor (PDGF-BB), a significant serum cytokine, is an important protein biomarker in diagnosis and recognition of cancer, which straightly rolled in proceeding of various cell transformations, including tumor growth and its development. Fibrosis, atherosclerosis are certain appalling diseases, which PDGF-BB is near to them. Generally, the expression amount of PDGF-BB increases in human life-threatening tumors serving as an indicator for tumor angiogenesis. Thus, identification and quantification of PDGF-BB in biomedical fields are particularly important. Affinity chromatography, immunohistochemical methods and enzyme-linked immunosorbent assay (ELISA), conventional methods for PDGF-BB detection, requiring high-cost and complicated instrumentation, take too much time and offer deficient sensitivity and selectivity, which restrict their usage in real applications. Hence, it is essential to design and build enhanced systems and platforms for the recognition and quantification of protein biomarkers. In the past few years, biosensors especially aptasensors have been received noticeable attention for the detection of PDGF-BB owing to their high sensitivity, selectivity, accuracy, fast response, and low cost. Since the role and importance of developing aptasensors in cancer diagnosis is undeniable. In this review, optical and electrochemical aptasensors, which have been applied by many researchers for PDGF-BB cancer biomarker detection, have been mentioned and merits and demerits of them have been explained and compared. Efforts related to design and development of aptamer-based biosensors using nanoparticles for sensitive and selective detection of PDGF-BB have been reviewed considering: Aptamer importance as recognition elements, principal, application and the recent improvements and developments of aptamer based optical and electrochemical methods. In addition, commercial biosensors and future perspectives for rapid and on-site detection of PDGF-BB have been summarized.

    更新日期:2018-04-25
  • Discrimination of single nucleotide mismatches using a scalable, flexible, and transparent three-dimensional nanostructure-based plasmonic miRNA sensor with high sensitivity
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-22
    Hee-Kyung Na, Jung-Sub Wi, Hye Young Son, Jong G. Ok, Yong-Min Huh, Tae Geol Lee

    Localized surface plasmon resonance (LSPR) biosensors have attracted much interest due to their capacity for multiplexing, miniaturization, and high performance, which offers the potential for their integration into lab-on-a-chip platforms for point-of-care (POC) diagnostics. The need for microRNA (miRNA)-sensing platforms is particularly urgent because miRNAs are key regulators and biomarkers in numerous pathological processes and diseases. Unfortunately, however, development of such miRNA-sensing platforms has not yet been achieved. In order to realize the detection of these important biomarkers, there has been an increasing demand for POC-sensing platforms that enable label-free quantification with low sample consumption, good sensitivity, real-time responsiveness, and high throughput. Here, we developed a highly specific, sensitive LSPR miRNA-sensing platform on a flexible, scalable plasmonic nanostructure to enable single-base mismatch discrimination and attomole detection of miRNAs in clinically relevant samples. The hairpin probe contained a locked nucleic acid (LNA) that enabled the discrimination of single base mismatches based on differences in melting temperatures of perfectly matched or single base mismatched miRNAs when they formed base pairs with probes. In addition, through hybridization induced signal amplification based on precipitate formation on the gold surface through the enzyme reaction, we observed a dramatic LSPR peak shift, which enabled attomole detection. Additionally, our LSPR miRNA sensor enabled the detection of miR-200a-3p in total RNA extracts from primary cancer cell lines without purification or labeling of the miRNA. This label-free and highly specific miRNA sensing platform may have applications in POC cancer diagnostics without the need for gene amplification.

    更新日期:2018-04-25
  • In situ detection of microbial c-type cytochrome based on intrinsic peroxidase-like activity using screen-printed carbon electrode
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-22
    Junlin Wen, Daigui He, Zhen Yu, Shungui Zhou

    C-type cytochromes (c-cyts) facilitate microbial extracellular electron transfer and play critical roles in biogeochemical cycling, bioelectricity generation and bioremediation. In this study, a simple and effective method has been developed to detect microbial c-type cytochrome (c-cyts) by means of peroxidase mimetic reaction on screen-printed carbon electrode (SPCE). To this end, bacteria cells were immobilized onto the working electrode surface of SPCE by a simple drop casting. After introducing 3,3’,5,5’-tetramethylbenzidine (TMB) solution, microbial c-cyts with peroxidase-like activity catalyze the oxidation of TMB in the presence of hydrogen peroxide. The oxidized TMB was electrochemically determined and the current signal was employed to calculate the c-cyts content. This electrochemical method is highly sensitive for microbial c-cyts with a low detection limit of 40.78 fmol and a wide detection range between 51.70 fmol and 6.64 pmol. Moreover, the proposed technique can be universally expanded to detect c-cyts in other bacteria species such as Fontibacter ferrireducens, Pseudomonas aeruginosa, Comamonas guangdongensis and Escherichia coli. Furthermore, the proposed method confers an in situ facile and quantitative c-cyts detection without any destructive sample preparations, complex electrode modifications and expensive enzyme- or metal particle- based signal amplification. The suggested method advances an intelligent strategy for in situ quantification of microbial c-cyts and consequently holds promising application potential in microbiology and environmental science.

    更新日期:2018-04-25
  • Detection of Bisphenol A in aqueous medium by screen printed carbon electrodes incorporating electrochemical molecularly imprinted polymers
    Biosens. Bioelectron. (IF 7.780) Pub Date : 2018-04-21
    Vitalys Mba Ekomo, Catherine Branger, Raphaël Bikanga, Ana-Mihaela Florea, Georges Istamboulie, Carole Calas-Blanchard, Thierry Noguer, Andrei Sarbu, Hugues Brisset

    Electrochemical molecularly imprinted polymers (e-MIPs) were for the first time introduced in screen-printed carbon electrodes (SPCE) as the sensing element for the detection of an organic pollutant. To play this sensing role, a redox tracer was incorporated inside the binding cavities of a cross-linked MIP, as a functional monomer during the synthesis step. Ferrocenylmethyl methacrylate was used for this purpose. It was associated with 4-vinylpyridine as a co-functional monomer and ethylene glycol dimethacrylate as cross-linker for the recognition of the endocrine disruptor, Bisphenol A (BPA), as a target. Microbeads of e-MIP and e-NIP (corresponding non-imprinted polymer) were obtained via precipitation polymerization in acetonitrile. The presence of ferrocene inside the polymers was assessed via FTIR and elemental analysis and the polymers microstructure was characterized by SEM and nitrogen adsorption/desorption experiments. Binding isotherms and batch selectivity experiments evidenced the presence of binding cavities inside the e-MIP and its high affinity for BPA compared to carbamazepine and ketoprofen. e-MIP (and e-NIP) microbeads were then incorporated in a graphite-hydroxyethylcellulose composite paste to prepare SPCE. Electrochemical properties of e-MIP-SPCE revealed a high sensitivity in the presence of BPA in aqueous medium compared to e-NIP-SPCE with a limit of detection (LOD) of 0.06 nM. Selectivity towards carbamazepine and ketoprofen was also observed with the e-MIP-SPCE.

    更新日期:2018-04-25
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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