In recent years, it is urgent and challenging to prepare highly sensitive and stable formaldehyde metal oxide gas sensing materials, as to in-situ detecting the indoor air pollutant. Here, stoichiometric InOCl mesoporous nanomaterial was synthesized by a facile sol-gel and successive calcination method. The dosage of HCl was found to be the key parameter for the stoichiometry of the InOCl, which was

The aptamer recognition mechanisms have been well developed based on equilibration between aptamer conformations modulated by ligand, and can be compatible with almost all kinds of readout techniques for aptamer-based biosensors (i.e., aptasensors). A novel and robust aptasensing strategy named “kinetic competition” has also been investigated in which the blocker kinetically competes the aptamer and

The electronic nose system is widely used to detect tea aroma, and the sensor array plays a fundamental role in detecting results. In this paper, we propose a sensor array optimization method based on correlation coefficient and cluster analysis. First, redundant sensors are assessed according to the correlation coefficient calculated between two sensors. The discriminating performance value (DPV)

Bisphenol compounds (BPs), as a group of endocrine disrupted compounds, have been posing serious risk on ecological environment and human health. The sensing of BPs is quite significant, but still in challenge. Here, we report, for the first time, a metal-organic framework (MOF) directly and alone, enables the selective and sensitive detection of BPs on its unique fluorescent change. This MOF is based

Since exosomes carry the genetic information of their parental cells, there is an increasing need for new technologies capable of detecting exosomes with high sensitivity and accuracy. In this study, we propose a dual antibody-modified nanochannel biosensor for rapid, sensitive analysis of exosomes. Two antibodies (anti-CD63 and anti-EpCAM) were simultaneously immobilized on the surface of the porous

A flexible and selective CO gas sensor was fabricated from Au-functionalized two-dimensional (2D) WS2 nanoflakes on polyamide substrate. Au-functionalized 2D WS2 nanoflakes gas sensors fabricated on polyamide can be operated under self-heating mode (1-5 V) with good selectivity to CO gas. Gas sensors fabricated on polyamide not only showed flexibility, but also demonstrated good stability and repeatability

In the present study, we fabricated a foldable all-in-one microdevice for the nucleic acid test (NAT) performing DNA extraction, polymerase chain reaction (PCR), and on-site colorimetric detection for point‐of‐care (POC) molecular diagnosis of multiple pathogens. The microdevice is composed of three layers. The top layer contains six filter paper discs pre-stored with PCR reagent. The middle layer

The Rb2CO3-decorated In2O3 sensor is prepared for detection of NO2 at room temperature under light irradiation. Physical and chemical properties of the materials and structures are thoroughly investigated by various analytical tools of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy, thereby confirming the formation

Nanocomposites of Zn1-xFexO/reduced graphene oxide (Zn1-xFexO/rGO, x = 0∼0.15) with carpet-like mesoporous structures have been simply synthesized via a low temperature hydrothermal method. FESEM and TEM results show that the hetero-assembly trend of Zn1-xFexO and rGO is much more striking than that of Zn1-xFexO self-assembly at 100 °C hydrothermal condition. The specific surface area and pore size

This work explores the potential of Fourier transform infrared (FTIR) spectroscopic imaging at the single-cell level combined with partial least squares (PLS) regression to investigate the cell’s response to drug/gold nanoparticles (AuNPs) conjugates. In a broader context, this study provides not only the effective differentiation between non-tumorigenic, mildly malignant and malignant cells, but above

One of the prerequisites for accurate measurements of relative humidity using thin-film humidity sensors is to obtain a single calibration equation that can be effectively applicable to individual sensors even at different temperatures. Here, we report on a normalization methodology in order to reduce difference among sensor units and also temperature dependency of humidity sensors based on quartz

In this study, a novel modification-free electrochemical sensing approach for thrombin that utilizes both electrically assisted bond and bisferrocene to enhance the signal output in a homogeneous solution was reported. First, the selected aptamer probe with a stem–loop structure was labeled with bisferrocene and thiol at the 3′ and 5′ terminals, respectively, and the closed–loop structure of the probe

Pure SnO2, SnO2/NiO, and Au-loaded SnO2/NiO hollow spheres with different Au content were synthesized through a 1-step hydrothermal synthesis. The surface morphology and structural as well as chemical composition of the synthesized Au-loaded SnO2/NiO hollow spheres were carefully investigated. The performance of the pure SnO2, SnO2/NiO, and Au-loaded SnO2/NiO gas sensors in the detection of low concentrations

Mucin 1 (MUC1) is abnormally expressed in tumor tissues, and quantitative analysis of MUC1 is thus beneficial to the prevention and early diagnosis of cancer. In this work, by intergrating DNAzyme with strand displacement reaction (SDR), we have fabricated a highly sensitive MUC1 colorimetric assay based on a multiple signal amplification strategy. Specifically, the presence of MUC1 can induce the

DNA methyltransferase catalyzes the methylation process of DNA. As a potential biomarker, methyltransferase activity assay has attracted more and more attention. Herein, we present a new biosensor based on cascade invasive reactions for DNA methyltransferase activity analysis. The sensing probes on the biosensor were first methylated by the Dam MTase and then cleaved by the DpnI endonuclease. The cleaved

In situ capacitance sensing is shown to be capable of monitoring critical morphological changes in industrial cultures by analyzing the sensor’s frequency spectrum. Scanning the frequency of an alternating current between the electrodes of a capacitance sensor, placed in a cell culture, allowed detection of the size change of microbial cells from shifts in the spectra. The frequency was scanned between

In this study, a novel potential-resolved ratiometric electrochemiluminescence (ECL) sensor, using Ru(bpy)32+ doped TiO2 nanoparticles (TiO2-Ru(bpy)32+ NPs) with polyethyleneimine (PEI) capped CdS quantum dots (PEI-CdS QDs) as new ECL emitter unit and molecularly imprinted polymer (MIP) as recognition element, was proposed for the first time. Owing to the large specific surface area and porosity of

Thyroglobulin (Tg) is an important index for the surveillance of differentiated thyroid carcinoma, and yet sensitive and specific protein detection still faces challenges in both biomedical research and clinical diagnosis. We described a novel approach to synthesize molecular imprinting polymers (MIPs)/hemin-graphene nanosheets (H-GNs) composites on the paper, using Tg and 3,3′,5,5′-tetramethylbenzidine

A novel electrochemical microfluidic separation and sensing (EMSS) device was fabricated for monitoring neurotransmitters (NTs) in human blood plasma. Initially, the neurotransmitter separation was achieved with the AC field perturbation in a microfluidic channel followed by the successive detection using a sensor at the end of channel. The sensor performances using some of electron transfer mediators

A novel electrochemical aptasensor was developed for multiple signal amplification based on [email protected]/MIL-101(Cr) as mimetic enzyme and RecJf Exo-assisted target recycling. For the detection of ochratoxin A (OTA), the catalytic ability of [email protected]/MIL-101(Cr) was better than that of [email protected] toward hydroquinone oxidation in the presence of H2O2, and the peak current increased

miRNAs have attracted increased attention as biomarkers, which have strong associations with diseases like cancers. Herein, we have constructed DNA four-way junction architecture on the surface of electrode for ultrasensitive electrochemical detection of miRNA. Isothermal duplex-specific nuclease catalyzed reaction and nicking endonuclease catalyzed reaction are performed on the synthesized novel magnetic

Hepatitis B virus (HBV) infection remains a global public health problem, which is directly associated with a very high risk of evolving into liver cirrhosis and hepatocellular carcinoma (HCC). So far, enzyme-linked immunosorbent assay (ELISA) is still a main detection method for HBV infection in hospital, by which it enables to identify HBV infection in vitro through detection of circulating hepatitis

Sulfur dioxide (SO2) is a toxic gas which poses a great threat on environmental protection and human health even at low concentration. Hence, considerable attention has been devoted to achieve accurate SO2 monitoring at ppb level. In this work, we report on a ppb-level SO2 detection system via deep ultraviolet differential optical absorption spectroscopy (DUV-DOAS). A novel concentration-retrieval

MEMS gas sensor arrays and specially designed pattern recognition systems are the main research directions in the field of modern sensing technology in the engineering, especially in the smart sensing and monitoring of faults in large power equipment such as oil-immersed transformers.In this paper, the MEMS sensor array composed by eight SWCNTs-based (pure, -OH functionalized, -COOH functionalized

A hydrodynamic snare and well array were developed to accomplish single-cell trapping and stem-cell perfusion culture. Directed streamline distribution is induced using unique V-shaped weir to load single bone marrow stem cell into U-shaped dwelling weir. The voids decrease flow speed in the dwelling area and enable a stable perfusion culture. The hydrodynamic snaring array was integrated with an on-line

Movement is essential to our quality of life, and regulates cell behavior via mechanical stimulation. Here, we report a monolithic microfluidic platform, in which engineered tissues composed of cells in a hydrogel are exposed to gradients of mechanical compression. Mechanical stimulation is applied through the deflection of a thin polydimethylsiloxane (PDMS) vertical membrane. The device design and

Depending on the contact line motion, evaporation of colloid-rich droplets can leave a ring-like or a spot-like residue. Herein, we determine this outcome by dynamically controlling the contact line motion using coplanar direct-current electrowetting-on-dielectrics (DC-EWOD). Thanks to the additional control over the contact angle, the contact line of evaporating droplets can be maintained in a pinned

Conventional affinity assays used for carbohydrate antigen (CA125) detection are still problematic due to the heterogeneity in the structure and molecular nature of CA125. This makes the conventional antibody based immunoassay difficult to detect CA125 levels accurately in clinical samples which demands the need for the development of new affinity-based detection without compromising specificity and

Human NAD(P)H: Quinone oxidoreductase 1 (NQO1) is over-expressed in many cancer cells. Thus, it is significant to establish a selective and sensitive method with high signal-to-background ratio for NQO1 detection and cancer diagnosis. Herein, an activatable biosensor based on water-soluble conjugated oligomer (OPFV-TLQ) was designed for highly sensitive detection of NQO1 and visualization imaging of

An ultrasensitive label-free electrochemical immunosensor using MoS2/NiCo heterostructures as an efficient signal enhancer was proposed for sensitive detection of procalcitonin. The MoS2/NiCo heterostructures were synthesized by thermally depositing MoS2 on NiCo MOFs nanocubes, which were then functionalized with in situ grown palladium nanoparticles (Pd NPs) for electrochemically catalyze the reduction