显示样式:     当前期刊: Talanta    加入关注    导出
我的关注
我的收藏
您暂时未登录!
登录
  • Hsa-miR-1587 G-quadruplex formation and dimerization induced by NH4+, molecular crowding environment and jatrorrhizine derivatives
    Talanta (IF 4.162) Pub Date : 2017-11-20
    Wei Tan, Long Yi, Zhentao Zhu, Lulu Zhang, Jiang Zhou, Gu Yuan

    A guanine-rich human mature microRNA, miR-1587, was discovered to form stable intramolecular G-quadruplexes in the presence of K+, Na+ and low concentration of NH4+ (25 mM) by electrospray ionization mass spectrometry (ESI-MS) combined with circular dichroism (CD) spectroscopy. Furthermore, under high concentration of NH4+ (100 mM) or molecular crowding environments, miR-1587 formed a dimeric G-quadruplex through 3’-to-3’ stacking of two monomeric G-quadruplex subunits with one ammonium ion sandwiched between the interfaces. Specifically, two synthesized jatrorrhizine derivatives with terminal amine groups could also induce the dimerization of miR-1587 G-quadruplex and formed 1:1 and 2:1 complexes with the dimeric G-quadruplex. In contrast, jatrorrhizine could bind with the dimeric miR-1587 G-quadruplex, but could not induce dimerization of miR-1587 G-quadruplex. These results provide a new strategy to regulate the functions of miR-1587 through induction of G-quadruplex formation and dimerization.

    更新日期:2017-11-20
  • Gold Leaf: From Gilding to the Fabrication of Disposable, Wearable and Low-cost Electrodes
    Talanta (IF 4.162) Pub Date : 2017-11-20
    Mauro Sérgio Ferreira Santos, Wilson Akira Ameku, Ivano Gebhardt Rolf Gutz, Thiago Regis Longo Cesar Paixão

    Gold is among the most used materials in electrocatalysis. Despite this, this noble metal is still too expensive to be used in the fabrication of low cost and disposable devices. In the present work, gold-leaf sheets, usually employed in decorative crafts and wedding candies, is introduced as an inexpensive source of gold. Planar-disc and nanoband gold electrodes were simply and easily manufactured by combining gold leaf and polyimide tape. The planar disc electrode exhibited electrochemical behavior similar to that of a commercial gold electrode in 0.2 mol·L−1 H2SO4; cyclic voltammetry of a 1 mmol·L−1 solution of potassium ferricyanide (K3[Fe(CN)6]) in 0.2 mol·L−1 KNO3, using this novel electrode, displayed an 80 mV difference between the oxidation and reduction peak potentials. The electrode also delivers promising prospects for the development of wearable devices. When submitted to severe mechanical deformation, this electrode exhibited neither loss of electrical contact nor significant variation in electrode response, even after fifteen bending and/or folding cycles. The thickness of the gold-leaf sheet facilitates the production of nanoband electrodes with behavior similar to that of ultramicroelectrodes. The electrode surface is easily renewed by cutting a thin slice off its end with a razor blade; this process led to limiting currents that were reproducible, presenting a relative standard deviation (RSD) of 3.8% (n=5).

    更新日期:2017-11-20
  • Bright-green-emissive nitrogen-doped carbon dots as a nanoprobe for bifunctional sensing, its logic gate operationand cellular imaging
    Talanta (IF 4.162) Pub Date : 2017-11-20
    Fangfang Du, Xiaojuan Gong, Wenjing Lu, Yang Liu, Yifang Gao, Shaomin Shuang, Ming Xian, Chuan Dong

    A fluorescent nanoprobe based on nitrogen-doped carbon dots (N-CDs) with green fluorescent emission have been fabricated through a facile one-step hydrothermal treatment using catechol and triethylene tetramine as precursors. The obtained N-CDs with excellent luminescent properties and superior biocompatibility have been applied for the development of a bifunctional sensor for the detection of Fe3+ and ascorbic acid (AA). Fe3+ that are tightly chelating the surface of N-CDs can induce fluorescence (FL) quenching of N-CDs through photo-induced electron transfer (PET). Meanwhile, the addition of AA serves to shelter the CDs effectively from being quenched by Fe3+ due to AA, as an antioxidant, enable easy-conversion of Fe3+ to reduced states (i.e. Fe3+ and Fe2+). The N-CDs are used as a facile and label-free “on-off-on” fluorescent nanoprobe for the determination of Fe3+ and AA with detection limits of 58.82 nM and 0.236 µM with the corresponding linear ranges of 25–200 µM and 25–300 µM, respectively. According to this phenomenon, an “AND” logic gate based on the novel N-CDs has been constructed. As-prepared N-CDs with negligible toxicity and perfect biocompatibility were expanded for cellular imaging and sensing Fe3+ and AA in living cell, which enlarges the application range of the N-CDs. Most importantly, the as-constructed fluorescent sensing system was successfully applied to detection of Fe3+ in tap water and the analyses of AA in fresh fruits with satisfactory results.

    更新日期:2017-11-20
  • Ultrasensitive and high specific detection of non-small-cell lung cancer cells in human serum and clinical pleural effusion by aptamer-based fluorescence spectroscopy
    Talanta (IF 4.162) Pub Date : 2017-11-20
    Yuhang Wu, Hong Zhang, Junfeng Xiang, Zhihua Mao, Gang Shen, Fengmin Yang, Yan Liu, Wei Wang, Ning Du, Jinghua Zhang, Yalin Tang

    Lung cancer is the leading cause of cancer-related deaths worldwide, and approximately 85% are diagnosed as non-small-cell lung cancer (NSCLC). However, efficient detection and diagnosis of NSCLC at early stage is still challenging. In this work, we developed a simple, ultrasensitive and high selective strategy for A549 human NSCLC cells detection based on combining the reorganization property of a novel cyanine dye 3,3′-di(3-sulfopropyl)−4,5,4′,5′-dibenzo-9-methyl-thiacarbocyanine triethylammonium salt (cy-M) to aptamer S6 G-quadruplex structure having specific affinity to NSCLC cells, which induced a dramatic fluorescence enhancement (~ 104 times). Moreover, this strategy was successfully used for detecting of A549 cancer cells in complex media such as human serum and clinical pleural effusion, which strong indicated that the proposed method could be applied for the early diagnosis of lung cancer.

    更新日期:2017-11-20
  • Novel approach in k0-NAA for highly concentrated REE Samples
    Talanta (IF 4.162) Pub Date : 2017-11-20
    M. Abdollahi Neisiani, M. Latifi, J. Chaouki, C. Chilian

    The present paper presents a new approach for k0-NAA for accurate quantification with short turnaround analysis times for rare earth elements (REEs) in high content mineral matrices. REE k0 and Q0 values, spectral interferences and nuclear interferences were experimentally evaluated and improved with Alfa Aesar Specpure Plasma Standard 1000 mg kg-1 mono-rare earth solutions. The new iterative gamma-ray self-attenuation and neutron self-shielding methods were investigated with powder standards prepared from 100 mg of 99.9% Alfa Aesar mono rare earth oxide diluted with silica oxide. The overall performance of the new k0-NAA method for REEs was validated using a certified reference material (CRM) from Canadian Certified Reference Materials Project (REE-2) with REE content ranging from 7.2 mg kg-1 for Yb to 9610 mg kg-1 for Ce. The REE concentration was determined with uncertainty below 7% (at 95% confidence level) and proved good consistency with the CRM certified concentrations.

    更新日期:2017-11-20
  • Carbon nanotubes magnetic hybrid nanocomposites for a rapid and selective preconcentration and clean-up of mercury species in water samples
    Talanta (IF 4.162) Pub Date : 2017-11-20
    Ana I. Corps Ricardo, Armando Sánchez-Cachero, María Jiménez-Moreno, Francisco J. Guzmán Bernardo, Rosa C. Rodríguez Martín-Doimeadios, Ángel Ríos

    Hybrid nanocomposites based on Fe3O4 magnetic nanoparticles (MNPs) coated with different types of carbon nanotubes (CNTs) have been studied for the first time as sorbent materials for magnetic solid phase extraction (MSPE) for mercury speciation analysis. Monomethylmercury (MMHg) was the target mercury species in water samples and the adsorption and desorption processes were optimized based on this species. Single-walled CNT-MNP showed higher adsorption capacity than double-walled or multi-walled CNTs. Then, the magnetic sorbent was retrieved with an external magnet and MMHg was selectively desorbed from it with dichloromethane (DCM) in two steps with vortex agitation. Inorganic mercury was removed during the desorption stage. The rapid adsorption and desorption equilibrium, the magnetic separation of the sorbent, and the simple and fast synthesis of CNT-MNPs without any additional modification of the CNTs simplified and shortened the extraction procedure. The extract was submitted to derivatization of the mercury species by ethylation (with an optional nitrogen stream evaporation of the organic phase) and injection into a gas chromatograph coupled to an atomic fluorescence detector (GC-pyro-AFS). The overall procedure provides the preconcentration of MMHg up to 150 times and the removal of inorganic mercury at the same time. The procedural limits of detection (LOD) and quantification (LOQ) were 5.4 and 17.9 pg mL−1, respectively. Moreover, magnetic nanocomposites can be reused at least 7 times without losing their efficiency. The methodology was validated in tap, dam and river water samples to evaluate the performance under real conditions with recoveries from 86 to 97% of spiked MMHg.

    更新日期:2017-11-20
  • An electrochemical aptasensor for the highly sensitive detection of 8-hydroxy-2′-deoxyguanosine based on the hybridization chain reaction
    Talanta (IF 4.162) Pub Date : 2017-11-20
    Li-Ping Jia, Li-Juan Wang, Rong-Na Ma, Lei Shang, Wei Zhang, Qing-Wang Xue, Huai-Sheng Wang

    In the present work a highly sensitive and selective aptasensor was developed for the determination of 8-hydroxy-2′-deoxyguanosine (8-OH-dG) based on the hybridization chain reaction (HCR) signal amplification. It was observed that the aptamer of 8-OH-dG could hybridize with the capture DNA immobilized on the gold electrode with a sticky tail left, which initiated the HCR and led to the formation of extended dsDNA structure on the electrode surface. Then the electroactive species ([Ru(NH3)6]3+, RuHex) intercalated into the dsDNA grooves to generate the amplified signal. However, in the presence of 8-OH-dG, the aptamer containing G-rich nucleic acid sequences would be induced to form a G-quadruplex structure, which made it impossible to continue the HCR. So the detection signal will significantly decrease. Under the optimal conditions, the peak current of RuHex was linear with the logarithm of 8-OH-dG concentration in the range from 10 pM to 100 μM with the detection limit of 2.5 pM. By integrating the merits of enzyme-free amplification power of the HCR and the inherent high sensitivity of the electrochemical technique, the prepared aptasensor not only showed high sensitivity for the detection of 8-OH-dG, but also exhibited good selectivity against to the uric acid, an important interferent in the urine sample. Particularly, the aptasensor was applied to detect 8-OH-dG in urine samples with satisfactory results.

    更新日期:2017-11-20
  • Novel synthesis of glucose functionalized magnetic graphene hydrophilic nanocomposites via facile thiolation for high-efficient enrichment of glycopeptides
    Talanta (IF 4.162) Pub Date : 2017-11-20
    Xiaoyan Feng, Chunhui Deng, Mingxia Gao, Guoquan Yan, Xiangmin Zhang

    High-efficient enrichment of glycopeptides prior to mass spectrometry is essential for glycoproteomics analysis. Hydrophilic interaction chromatography (HILIC) approach is a prominent strategy for glycopeptides identification. In this work, glucose functionalized magnetic graphene hydrophilic nanocomposite (MagG/Au/Glu) was synthesized as a novel HILIC material via a facile surface modification strategy. Different from previous click synthesis of saccharides-functionalized materials, glucose was easily thiolated via Traut's reagent and then immobilized on the materials via efficient Au-S coupling, greatly simplifying the synthesis process. Combining the rapid magnetic response, huge surface area from graphene and excellent hydrophilicity from glucose, MagG/Au/Glu nanocomposites afforded convenience of the operation and affinity for glycopeptides. Thus, the nanocomposites exhibited superior performance of high sensitivity, selectivity and reusability in glycopeptide enrichment from tryptic digests of standard glycoprotein HRP. Encouragingly, with the usage of MagG/Au/Glu nanocomposites, a total of 305 glycopeptides assigned to 108 glycoproteins were identified from complex real sample human serum, indicating a great potential for the application of glycoproteomics research.

    更新日期:2017-11-20
  • A dual-targeting DNA tetrahedron nanocarrier for breast cancer cell imaging and drug delivery
    Talanta (IF 4.162) Pub Date : 2017-11-20
    Xiaoting Liu, Lina Wu, Lei Wang, Wei Jiang

    To enhance efficacy of chemotherapy and achieve real-time imaging of cancer cells, it is crucial to develop nanocarriers with targeted drug delivery capacity and fluorescence property for cancer theranostics. Herein, a dual-targeting DNA tetrahedron nanocarrier (MUC1-Td-AS1411) was constructed for breast cancer cell imaging and targeted drug delivery. This nanocarrier consisted of three components: (i) DNA tetrahedron core for multivalent conjugation of function ligands and loading doxorubicin (Dox); (ii) activatable MUC1 aptamer probe (MUC1-probe), formed by the hybridization of MUC1 aptamer sequence with fluorophore extended from one vertex and complementary sequence with quencher, for targeting and imaging MUC1 protein on cytomembrane; (iii) AS1411 aptamer, which was hybridized to the overhang on three vertexes via prolonged sequence, for binding to nucleolin. Firstly, MUC1-probe of this nanocarrier targeted MUC1 protein of MUC1-positive cells, causing a conformational reorganization of MUC1 aptamer, releasing complementary sequence with quencher and leading to fluorescence recovery. Subsequently, after internalizing into cells, AS1411 aptamer moiety of nanocarrier bound to nucleolin selectively, then the whole nanocarrier targeted nucleus and released Dox into nucleus. MUC1-positive cells and MUC1-negative cells could be differentiated by means of fluorescence imaging. Versus free Dox, Dox-loaded MUC1-Td-AS1411 showed lower cytotoxicity to MUC1-negative HL-7702 cells (P < 0.01), approximately equal lethality to sensitive MCF-7 cells (P > 0.05) whereas more effective to doxorubicin-resistant MCF-7 cells (P < 0.01). Therefore, this nanocarrier could be used as a promising candidate for cancer theranostics.

    更新日期:2017-11-20
  • Calibration transfer of a Raman spectroscopic quantification method for the assessment of liquid detergent compositions from at-line laboratory to in-line industrial scale
    Talanta (IF 4.162) Pub Date : 2017-11-20
    D. Brouckaert, J.-S. Uyttersprot, W. Broeckx, T. De Beer

    Calibration transfer or standardisation aims at creating a uniform spectral response on different spectroscopic instruments or under varying conditions, without requiring a full recalibration for each situation. In the current study, this strategy is applied to construct at-line multivariate calibration models and consequently employ them in-line in a continuous industrial production line, using the same spectrometer. Firstly, quantitative multivariate models are constructed at-line at laboratory scale for predicting the concentration of two main ingredients in hard surface cleaners. By regressing the Raman spectra of a set of small-scale calibration samples against their reference concentration values, partial least squares (PLS) models are developed to quantify the surfactant levels in the liquid detergent compositions under investigation. After evaluating the models performance with a set of independent validation samples, a univariate slope/bias correction is applied in view of transporting these at-line calibration models to an in-line manufacturing set-up. This standardisation technique allows a fast and easy transfer of the PLS regression models, by simply correcting the model predictions on the in-line set-up, without adjusting anything to the original multivariate calibration models. An extensive statistical analysis is performed in order to assess the predictive quality of the transferred regression models. Before and after transfer, the R2 and RMSEP of both models is compared for evaluating if their magnitude is similar. T-tests are then performed to investigate whether the slope and intercept of the transferred regression line are not statistically different from 1 and 0, respectively. Furthermore, it is inspected whether no significant bias can be noted. F-tests are executed as well, for assessing the linearity of the transfer regression line and for investigating the statistical coincidence of the transfer and validation regression line. Finally, a paired t-test is performed to compare the original at-line model to the slope/bias corrected in-line model, using interval hypotheses. It is shown that the calibration models of Surfactant 1 and Surfactant 2 yield satisfactory in-line predictions after slope/bias correction. While Surfactant 1 passes seven out of eight statistical tests, the recommended validation parameters are 100% successful for Surfactant 2. It is hence concluded that the proposed strategy for transferring at-line calibration models to an in-line industrial environment via a univariate slope/bias correction of the predicted values offers a successful standardisation approach.

    更新日期:2017-11-20
  • Raman Spectra of Thiolated Arsenicals with Biological Importance
    Talanta (IF 4.162) Pub Date : 2017-11-17
    Mingwei Yang, Yuzhen Sun, Xiaobin Zhang, Bruce McCord, Anthony J. McGoron, Alexander Mebel, Yong Cai

    Surface enhanced Raman scattering (SERS) has great potential as an alternative tool for arsenic speciation in biological matrices. SERS measurements have advantages over other techniques due to its ability to maintain the integrity of arsenic species and its minimal requirements for sample preparation. Up to now, very few Raman spectra of arsenic compounds have been reported. This is particularly true for thiolated arsenicals, which have recently been found to be widely present in humans. The lack of data for Raman spectra in arsenic speciation hampers the development of new tools using SERS. Herein, we report the results of a study combining the analysis of experimental Raman spectra with that obtained from density functional calculations for some important arsenic metabolites. The results were obtained with a hybrid functional B3LYP approach using different basis sets to calculate Raman spectra of the selected arsenicals. By comparing experimental and calculated spectra of dimethylarsinic acid (DMAV), the basis set 6–311++G⁎⁎ was found to provide computational efficiency and precision in vibrational frequency prediction. The Raman frequencies for the rest of organoarsenicals were studied using this basis set, including monomethylarsonous acid (MMAIII), dimethylarsinous acid (DMAIII), dimethylmonothioarinic acid (DMMTAV), dimethyldithioarsinic acid (DMDTAV), S-(Dimethylarsenic) cysteine (DMAIII(Cys)) and dimethylarsinous glutathione (DMAIIIGS). The results were compared with fingerprint Raman frequencies from As─O, As─C, and As─S obtained under different chemical environments. These fingerprint vibrational frequencies should prove useful in future measurements of different species of arsenic using SERS.

    更新日期:2017-11-20
  • Identification and classification of cathinone unknowns by statistical analysis processing of direct analysis in real time-high resolution mass spectrometry-derived “neutral loss” spectra
    Talanta (IF 4.162) Pub Date : 2017-11-16
    Kristen L. Fowble, Jason R.E. Shepard, Rabi A. Musah

    An approach to the rapid determination of the structures of novel synthetic cathinone designer drugs, also known as bath salts, is reported. While cathinones fragment so extensively by electron impact mass spectrometry that their mass spectra often cannot be used to identify the structure, collision-induced dissociation (CID) direct analysis in real time-high resolution mass spectrometry (DART-HRMS) experiments furnished spectra that provided diagnostic fragmentation patterns for the analyzed cathinones. From this data, neutral loss spectra, which reflect the presence of specific chemical moieties, could be acquired. These spectra showed striking similarities between cathinones sharing structural features such as pyrrolidine rings and methylenedioxy moieties. Principle component analysis (PCA) of the neutral loss spectra of nine synthetic cathinones of various types including ethcathinones, those containing a methylenedioxy moiety appended to the benzene ring, and pyrrolidine-containing structures, illustrated that cathinones falling within the same class clustered together and could be distinguished from those of other classes. Furthermore, hierarchical clustering analysis of the neutral loss data of a model set derived from 44 synthetic cathinones, furnished a dendrogram in which structurally similar cathinones clustered together. The ability of this model system to facilitate structure determination was tested using 4-fluoroethcathinone, 3,4-methylenedioxy-α-pyrrolidinohexanophenone (MDPHP), and ethylone, which fall into the ethcathinone, pyrrolidine-containing, and methylenedioxy-containing subclasses respectively. The results showed that their neutral loss spectra correctly fell within the ethcathinone, pyrrolidine-containing and methylenedioxy-containing cathinone clades of the dendrogram, and that the neutral loss information could be used to infer the structures of these compounds. The analysis and data processing steps are rapid and samples can be analyzed in their native form without any sample processing steps. The robustness of the dendrogram dataset can be readily increased by continued addition of newly discovered structures. The approach can be broadly applied to structure determination of unknowns, and would be particularly useful for analyses where sample amounts are limited.

    更新日期:2017-11-20
  • Biospecific isolation and characterization of angiogenesis-promoting ingredients in Buyang Huanwu decoction using affinity chromatography on rat brain microvascular endothelial cells, solid-phase extraction, and HPLC-MS/MS
    Talanta (IF 4.162) Pub Date : 2017-11-15
    Fengyun Liao, Yingjiao Meng, Huazhu Zheng, Dongmei He, Xiao Shen, Jianye Yu, Yingai Wu, Lisheng Wang

    Buyang Huanwu decoction (BHD) was reported to exert angiogenesis-promoting effects, but its active ingredients remain unknown. In this study, we developed a method to screen potential angiogenesis-promoting compounds in BHD, which involved biospecific isolation using live rat brain microvascular endothelial cells (rBMECs) and characterization using solid-phase extraction (SPE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Six compounds showed binding affinity to rBMECs and were further identified as 6-hydroxykaempferol-di-O-glucoside, paeoniflorin, calycosin-7-O-β-D-glucoside, galloylpaeoniflorin, formononetin-7-O-β-D-glucoside, and (3 R)−7,2’-hydroxy-3’,4’-dimethoxy-isoflavan. The results indicated that five of them except 6-hydroxykaempferol-di-O-glucoside showed a protective effect against oxygen glucose deprivation/reperfusion injury in rBMECs and upregulated the secretion of vascular endothelial growth factor and basic fibroblast growth factor, suggesting a mechanism underlying their angiogenic activity. Our findings suggest that biospecific live cell-based isolation combined with SPE and HPLC-MS/MS is an effective method for screening potential bioactive components in traditional Chinese medicines.

    更新日期:2017-11-16
  • Highly sensitive and simple liquid chromatography assay with ion-pairing extraction and visible detection for quantification of gold from nanoparticles
    Talanta (IF 4.162) Pub Date : 2017-11-14
    Arnaud Pallotta, Valentin Philippe, Ariane Boudier, Pierre Leroy, Igor Clarot

    A simple isocratic HPLC method using visible detection was developed and validated for the quantification of gold in nanoparticles (AuNP). After a first step of oxidation of nanoparticles, an ion-pair between tetrachloroaurate anion and the cationic dye Rhodamine B was formed and extracted from the aqueous media with the help of an organic solvent. The corresponding Rhodamine B was finally quantified by reversed phase liquid chromatography using a Nucleosil C18 (150 mm × 4.6 mm, 3 µm) column and with a mobile phase containing acetonitrile and 0.1% trifluoroacetic acid aqueous solution (25/75, V/V) at 1.0 mL.min-1.and at a wavelength of 555 nm. The method was validated using methodology described by the International Conference on Harmonization and was shown to be specific, precise (RSD < 11%), accurate and linear in the range of 0.1 – 30.0 µM with a lower limit of quantification (LLOQ) of 0.1 µM. This method was in a first time applied to AuNP quality control after their synthesis. In a second time, the absence of gold leakage (either as AuNP or gold salt form) from nanostructured multilayered polyelectrolyte films under shear stress was assessed.

    更新日期:2017-11-15
  • Luminescent quantum dots for miRNA detection
    Talanta (IF 4.162) Pub Date : 2017-11-12
    O.A. Goryacheva, P.K. Mishra, Yu I. Goryacheva

    MicroRNAs (miRNAs) are a class of small non-coding RNAs that are involved in nearly all developmental processes and human pathologies. MiRNAs are considered to be promising biomarkers, since their dysregulation correlates with the development and progress of many diseases. Short length, sequence homology among family members, susceptibility to degradation, and low abundance in total RNA samples make miRNA analysis a challenging task. Photoluminescent semiconductor nanoparticles (quantum dots, QDs) possess unique properties such as bright photoluminescence, photostability and narrow emission peaks, wide possibilities for surface modification and bioconjugation, which serve as the basis for the development of different analytical methods for variety of analytes. Relatively small size of QDs’ and their narrow distribution are especially important for miRNA assay. The combination of QD-based biosensors with amplification techniques makes it possible to identify the target miRNA at a single-particle level with the detection limit at the attomolar scale. This review describes the principles of signal generation: direct intensity measurements, different “signal on” and “signal off” mechanisms as well as electro-chemiluminescence. Special attention is paid to the FRET-based techniques. According to our knowledge this is the first review related to QDs application for miRNA detection.

    更新日期:2017-11-13
  • Determination of Pb in environmental samples after cloud point extraction using crown ether
    Talanta (IF 4.162) Pub Date : 2017-11-11
    Guillaume Blanchet-Chouinard, Dominic Larivière

    In the present study, a new cloud point extraction methodology based on the selective preconcentration and the extraction of stable lead in acidic conditions with 4',4''(5'')-di-tert-butyldicyclohexano-18-crown-6 as a chelating agent was developed, optimized and validated. A mixture of Triton X-114 as non-ionic surfactant and CTAB as cationic surfactant was used to produce micellar structures that incorporate the chelating agent. Phase separation, induced by coacervation, was achieved by increasing the temperature of the system above the cloud point temperature. Pb extraction efficiency was maximized through an optimization process where the effect of each parameter (i.e. non-ionic and ionic surfactant concentrations, pH, chelating agent concentration and cloud point temperature) on the chemical recoveries of Pb was assessed. Under optimum experimental conditions, the method reaches recoveries greater than 67% for Pb in a variety of complex matrices. In order to facilitate the quantification of Pb by plasma based instrumentations, a back-extraction procedure using aqueous solution of ammonium citrate were performed on the surfactant rich phase in order to reduce the effects on sample introduction and non-spectral interferences. LOD and LOQ of 0.8 µg L−1 and 2.6 µg L−1, respectively, were determined by ICP-OES for the complete procedure. Using the back-extraction approach, a preconcentration factor of 39 was achieved for an initial sample volume of 195 mL. The ruggedness of the methodology was validated by determining Pb concentration in various environmental and biological samples.

    更新日期:2017-11-13
  • Real-time monitoring of a coffee roasting process with near infrared spectroscopy using multivariate statistical analysis: a feasibility study
    Talanta (IF 4.162) Pub Date : 2017-11-11
    Tiago A. Catelani, João Rodrigo Santos, Ricardo N.M.J. Páscoa, Leonardo Pezza, Helena R. Pezza, João A. Lopes

    This work proposes the use of near infrared (NIR) spectroscopy in diffuse reflectance mode and multivariate statistical process control (MSPC) based on principal component analysis (PCA) for real-time monitoring of the coffee roasting process. The main objective was the development of a MSPC methodology able to early detect disturbances to the roasting process resourcing to real-time acquisition of NIR spectra. A total of fifteen roasting batches were defined according to an experimental design to develop the MSPC models. This methodology was tested on a set of five batches where disturbances of different nature were imposed to simulate real faulty situations. Some of these batches were used to optimize the model while the remaining was used to test the methodology. A modelling strategy based on a time sliding window provided the best results in terms of distinguishing batches with and without disturbances, resourcing to typical MSPC charts: Hotelling's T2 and squared predicted error statistics. A PCA model encompassing a time window of four minutes with three principal components was able to efficiently detect all disturbances assayed. NIR spectroscopy combined with the MSPC approach proved to be an adequate auxiliary tool for coffee roasters to detect faults in a conventional roasting process in real-time.

    更新日期:2017-11-11
  • Chip-based magnetic solid phase microextraction coupled with ICP-MS for the determination of Cd and Se in HepG2 cells incubated with CdSe quantum dots
    Talanta (IF 4.162) Pub Date : 2017-11-10
    Xiaoxiao Yu, Beibei Chen, Man He, Han Wang, Bin Hu

    The quantification of trace Cd and Se in cells incubated with CdSe quantum dots (QDs) is critical to investigate the cytotoxicity of CdSe QDs. In this work, a miniaturized platform, namely chip-based magnetic solid phase microextraction (MSPME) packing with sulfhydryl group functionalized magnetic nanoparticles, was fabricated and combined with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of trace Cd and Se in cells. Under the optimized conditions, the limits of detection (LOD) of the developed chip-based MSPME-ICP-MS system are 2.2 and 21 ng L−1 for Cd and Se, respectively. The proposed method is applied successfully to the analysis of total and released small molecular fraction of Cd and Se in Human hepatocellular carcinoma cells (HepG2 cells) incubated with CdSe QDs, and the recoveries for the spiked samples are in the range of 86.0–109%. This method shows great promise to analyze cell samples and the obtained results are instructive to explore the cytotoxicity mechanism of CdSe QDs in cells.

    更新日期:2017-11-11
  • Flow analysis with chemiluminescence detection: recent advances and applications
    Talanta (IF 4.162) Pub Date : 2017-11-10
    Irina I. Timofeeva, Christina S. Vakh, Andrey V. Bulatov, Paul J. Worsfold

    This article highlights the most important developments in flow analysis with chemiluminescence (CL) detection, describing different flow systems that are compatible with CL detection, detector designs, commonly applied CL reactions and approaches to sample treatment. Recent applications of flow analysis with CL detection (focusing on outputs published since 2010) are also presented. Applications are classified by sample matrix, covering foods and beverages, environmental matrices, pharmaceuticals and biological fluids. Comprehensive tables are provided for each area, listing the specific sample matrix, CL reaction used, linear range, limit of detection and sample treatment for each analyte. Finally, recent and emerging trends in the field are also discussed.

    更新日期:2017-11-11
  • Label-free photoluminescence assay for nitrofurantoin detection in lake water samples using adenosine-stabilized copper nanoclusters as nanoprobes
    Talanta (IF 4.162) Pub Date : 2017-11-10
    Yong Wang, Tianxia Chen, Qianfen Zhuang, Yongnian Ni

    In this paper, we constructed a novel label-free analytical strategy for highly sensitive and selective detection of nitrofurantoin (NFT) based on adenosine-stabilized copper nanoclusters (CuNCs) as nanoprobes. It was found that NFT caused a rapid decrease in the photoluminescence intensity of CuNCs. The photoluminescence quenching was likely attributed to the inner filter effect between NFT and CuNCs. The CuNCs exhibited a wide linear range of 0.05–4.0 μM with the detection limit of 30 nM (7.1 ng mL−1) for detection of NFT. And it was successfully applied for NFT detection in lake water samples.

    更新日期:2017-11-10
  • Effect of salinity and pH on the calibration of the extraction of pharmaceuticals from water by PASSIL
    Talanta (IF 4.162) Pub Date : 2017-11-09
    Hanna Męczykowska, Piotr Stepnowski, Magda Caban

    High salinity and a relatively high pH are two factors characterizing the marine water environment, which is one of the main final reservoirs receiving pharmaceutical residues. The same factors have an undeniable impact on the extraction efficiency and kinetics of uptakes of polar analytes from water by sorbent-based passive sampling techniques. Recently, we presented a novel passive sampling technique, in which ionic liquids are applied as receiving phases for pharmaceutical monitoring in water (the Passive Sampling with Ionic Liquids technique). In this paper we test the impact of salinity and pH on the PASSIL calibration (sampling rate determination) and the extraction efficiencies of sulfonamides, beta-blockers and nonsteroidal anti-inflammatory drugs selected as model contaminants. Trihexyl(tetradecyl)phosphonium dicyanamide ([P666-14][N(CN)2]) was taken as the stable liquid receiving phase. It selectively extracted neutral and negatively charged analytes from donor solutions of different pH (1, 3, 7 and 9). The presence of salt (7, 20 and 35 PSU) decreased the efficiency (by 5% to 65%) and Rs (by 0.017 L day−1 to 0.574 L day−1) of PASSIL for all target compounds. The general conclusion is that salinity and pH have a significant impact on the calibration of passive dosimeters for ionizable compounds, both for the new PASSIL technique and standard POCIS techniques.

    更新日期:2017-11-10
  • Electro-driven extraction of polar compounds using agarose gel as a new membrane: Determination of amino acids in fruit juice and human plasma samples
    Talanta (IF 4.162) Pub Date : 2017-11-07
    Samira Sedehi, Hadi Tabani, Saeed Nojavan

    In this work, polypropylene hollow fiber was replaced by agarose gel in conventional electro membrane extraction (EME) to develop a novel approach. The proposed EME method was then employed to extract two amino acids (tyrosine and phenylalanine) as model polar analytes, followed by HPLC-UV. The method showed acceptable results under optimized conditions. This green methodology outperformed conventional EME, and required neither organic solvents nor carriers. The effective parameters such as the pH values of the acceptor and the donor solutions, the thickness and pH of the gel, the extraction voltage, the stirring rate, and the extraction time were optimized. Under the optimized conditions (acceptor solution pH: 1.5; donor solution pH: 2.5; agarose gel thickness: 7 mm; agarose gel pH: 1.5; stirring rate of the sample solution: 1000 rpm; extraction potential: 40 V; and extraction time: 15 min), the limits of detection and quantification were 7.5 ng mL−1 and 25 ng mL−1, respectively. The extraction recoveries were between 56.6 and 85.0%, and the calibration curves were linear with correlation coefficients above 0.996 over a concentration range of 25.0–1000.0 ng mL−1 for both amino acids. The intra- and inter-day precisions were in the range of 5.5–12.5%, and relative errors were smaller than 12.0%. Finally, the optimized method was successfully applied to preconcentrate, clean up, and quantify amino acids in watermelon and grapefruit juices as well as a plasma sample, and acceptable relative recoveries in the range of 53.9–84.0% were obtained.

    更新日期:2017-11-10
  • Development of Liquid Chromatography High Resolution Mass Spectrometry Strategies for the Screening of Complex Organic Matter: Application to Astrophysical Simulated Materials
    Talanta (IF 4.162) Pub Date : 2017-11-07
    Balkis Eddhif, Audrey Allavena, Sylvie Liu, Thomas Ribette, Ninette Abou Mrad, Thierry Chiavassa, Louis Le Sergeant d’Hendecourt, Robert Sternberg, Gregoire Danger, Claude Geffroy-Rodier, Pauline Poinot

    The present work aims at developing two LC-HRMS setups for the screening of organic matter in astrophysical samples. Their analytical development has been demonstrated on a 100-microgram residue coming from the photo-thermo chemical processing of a cometary ice analog produced in laboratory.The first 1D-LC-HRMS setup combines a serially coupled columns configuration with HRMS detection. It has allowed to discriminate among different chemical families (amino acids, sugars, nucleobases and oligopeptides) in only one chromatographic run without neither a priori acid hydrolysis nor chemical derivatisation. The second setup is a dual-LC configuration which connects a series of trapping columns with analytical reverse-phase columns. By coupling on-line these two distinct LC units with a HRMS detection, high mass compounds (350 < m/z < 600) have been efficiently preconcentrated, separated and detected.Our strategies demonstrate a real interest for the analysis of astrophysical samples coming in minute quantities and allowing only few analytical runs. Besides its relevance for astrobiological studies, this work points out the suitability of these two novel LC-HRMS strategies for untargeted analysis of complex environmental samples.

    更新日期:2017-11-10
  • Specific chemiluminescent protocol for dual-site recognition of Streptococcus mutans utilizing strong affinity between teicoplanin and Gram-positive bacteria
    Talanta (IF 4.162) Pub Date : 2017-11-06
    Xiaoxiao Su, Mengyao Wang, Yue Wu, Yong He, Zhifeng Fu

    A novel dual-site recognition protocol was developed for chemiluminescent (CL) detection of Streptococcus mutans (S. mutans) based on a designed antibiotic-affinity strategy. Teicoplanin, a broad-spectrum antibiotic against Gram-positive bacteria, was adopted to functionalize magnetic particles and recognize S. mutans utilizing the strong affinity between this agent and D-Alanyl-D-Alanine peptide moieties in the bacterial cell wall. To achieve ideal specificity for S. mutans detection, rat immunoglobulin G2a (rat IgG2a) tagged with horseradish peroxidase (HRP) was used as the second recognition agent and signal tracer since Fab region of rat IgG2a could bind with streptococcal protein G highly expressed in the cell wall of S. mutans. Thus HRP-tagged sandwich complex of teicoplanin/S. mutans/rat IgG2a was formed on the magnetic particles, followed by a CL quantification of S. mutans based on a HRP-catalyzed luminol-H2O2-p-iodophenol CL reaction. This dual-site recognition protocol showed a linear range of 1.0 × 102 − 1.0 × 106 CFU mL−1 and a detection limit of 33 CFU mL−1 for S. mutans detection. The whole detection process could be completed within 70 min. The recovery tests for food, environmental, pharmaceutical and biological samples showed acceptable recovery values between 83.0% and 110.0%, demonstrating its application potential for detection of bacteria in various sample matrixes.

    更新日期:2017-11-10
  • A single-state fluorescent with bright white-light emission in the solid station and aggregation-induced emission enhancement compound for Pd° detection
    Talanta (IF 4.162) Pub Date : 2017-11-04
    Yan Zhang, Yexin Li, Xiaofeng Yang, Yiming Ding, Zongshi Zhao, Xiaolei Liu, Zhen Yang, Yu Cui
    更新日期:2017-11-05
  • 更新日期:2017-11-05
  • Quantitative analysis of drug distribution by ambient mass spectrometry imaging method with signal extinction normalization strategy and inkjet-printing technology
    Talanta (IF 4.162) Pub Date : 2017-11-04
    Zhigang Luo, Jingjing He, Jiuming He, Lan Huang, Xiaowei Song, Xin Li, Zeper Abliz
    更新日期:2017-11-05
  • Portable vibration-assisted filtration device for on-site isolation of blood cells or pathogenic bacteria from whole human blood
    Talanta (IF 4.162) Pub Date : 2017-11-04
    Yong Tae Kim, Kyun Joo Park, Seyl Kim, Soon Ae Kim, Seok Jae Lee, Do Hyun Kim, Tae Jae Lee, Kyoung G. Lee
    更新日期:2017-11-05
  • Glucose-Bridged Silver Nanoparticle Assemblies for Highly Sensitive Molecular Recognition of Sialic Acid on Cancer Cells via Surface-Enhanced Raman Scattering Spectroscopy
    Talanta (IF 4.162) Pub Date : 2017-11-04
    Rong Deng, Jing Yue, Huixin Qu, Lijia Liang, Dan Sun, Jing Zhang, Chongyang Liang, Weiqing Xu, Shuping Xu
    更新日期:2017-11-05
  • An On-line Solid-phase Extraction Disc Packed with a Phytic Acid Induced 3D Graphene-Based Foam for the Sensitive HPLC-PDA Determination of Bisphenol A Migration in Disposable Syringes
    Talanta (IF 4.162) Pub Date : 2017-11-04
    Qiuhong Yao, Yufeng Feng, Connieal Tan, Shujun Xia, Li Zhao, Shuya Wang, Yiru Wang, Xi Chen
    更新日期:2017-11-05
  • Fabrication of novel superoxide anion biosensor based on 3D interface of mussel-inspired Fe3O4-Mn3(PO3)2@Ni foam
    Talanta (IF 4.162) Pub Date : 2017-11-02
    Qi Wang, Qian Zhou, Qicheng Zhang, Rongjia Shi, Shangshang Ma, Wenbo Zhao, Min Zhou
    更新日期:2017-11-03
  • 更新日期:2017-11-01
  • An electrochemical immunosensor for brain natriuretic peptide prepared with screen-printed carbon electrodes nanostructured with goldnanoparticles grafted through aryl diazonium salt chemistry
    Talanta (IF 4.162) Pub Date : 2017-10-31
    V. Serafín, R.M. Torrente-Rodríguez, A. González-Cortés, P. García de Frutos, M. Sabaté, S. Campuzano, P. Yáñez-Sedeño, J.M. Pingarrón
    更新日期:2017-11-01
  • Highly Fluorescent Sensing of Nitroaromatic Explosives in Aqueous Media using Pyrene-Linked PBEMA Microspheres
    Talanta (IF 4.162) Pub Date : 2017-10-31
    Hamza Turhan, Ece Tukenmez, Bunyamin Karagoz, Niyazi Bicak
    更新日期:2017-11-01
  • Raman hyperspectral imaging as an effective and highly informative tool to study the diagenetic alteration of fossil bones
    Talanta (IF 4.162) Pub Date : 2017-10-31
    Gregorio Dal Sasso, Ivana Angelini, Lara Maritan, Gilberto Artioli
    更新日期:2017-11-01
  • A VISCOUS FILM SAMPLE CHAMBER FOR LASER ABLATION INDUCTIVELY COUPLED PLASMA – MASS SPECTROMETRY
    Talanta (IF 4.162) Pub Date : 2017-10-31
    Damiano Monticelli, Davide Civati, Barbara Giussani, Carlo Dossi, Davide Spanu, Sandro Recchia
    更新日期:2017-11-01
  • UHPLC-MS/MS and MALDI-MS study of aluminum phthalocyanine chloride and development of a bioanalytical method for its quantification in nanoemulsions and biological matrices
    Talanta (IF 4.162) Pub Date : 2017-10-28
    Karen R. Py-Daniel, Javier Calvo, Carlos M. Infante C., Osmindo R. Pires Junior, Sergio H. Moya, Ricardo B. Azevedo
    更新日期:2017-10-28
  • Determination of the structure and composition of Au-Ag bimetallic spherical nanoparticles using single particle ICP-MS measurements performed with normal and high temporal resolution
    Talanta (IF 4.162) Pub Date : 2017-10-27
    Albert Kéri, Ildikó Kálomista, Ditta Ungor, Ádám Bélteki, Edit Csapó, Imre Dékány, Thomas Prohaska, Gábor Galbács
    更新日期:2017-10-28
  • Simultaneous determination of V, Ni and Fe in fuel fly ash using solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry
    Talanta (IF 4.162) Pub Date : 2017-10-27
    A. Cárdenas Valdivia, E. Vereda Alonso, M.M. López Guerrero, J. Gonzalez-Rodriguez, J.M. Cano Pavón, A. García de Torres
    更新日期:2017-10-27
  • SERS strategy based on the modified Au nanoparticles for highly sensitive detection of bisphenol A residues in milk
    Talanta (IF 4.162) Pub Date : 2017-10-26
    Libin Yang, Yongliang Chen, Yu Shen, Ming Yang, Xiuling Li, Xiaoxia Han, Xin Jiang, Bing Zhao
    更新日期:2017-10-27
  • 更新日期:2017-10-25
  • 更新日期:2017-10-25
  • 更新日期:2017-10-24
  • Exploiting multivariate calibration for compensation of iron interference in the spectrophotometric flow-based catalytic determination of molybdenum
    Talanta (IF 4.162) Pub Date : 2017-10-24
    Eliezer Oliveira, Camelia Henriquez, Lidiane C. Nunes, Elias A.G. Zagatto
    更新日期:2017-10-24
  • Voltammetric Detection of Antimony in Natural Water on Cathodically Pretreated Microcrystalline Boron Doped Diamond Electrode: A Possibility How to Eliminate Interference of Arsenic without Surface Modification
    Talanta (IF 4.162) Pub Date : 2017-10-24
    Zuzana Lukáčová-Chomisteková, Eva Culková, Renata Bellová, Danica Melicherčíková, Jaroslav Durdiak, Ernest Beinrohr, Miroslav Rievaj, Peter Tomčík
    更新日期:2017-10-24
  • One-step direct immunoassay with horseradish peroxidase as antigen for studying the functionality of antibody surfaces
    Talanta (IF 4.162) Pub Date : 2017-10-23
    G. Coussot, C. Faye, A. Le Postollec, M. Dobrijevic
    更新日期:2017-10-24
  • A quantum dot-based lateral flow immunoassay for the sensitive detection of human heart fatty acid binding protein (hFABP) in human serum
    Talanta (IF 4.162) Pub Date : 2017-10-23
    Mihaela Savin, Carmen-Marinela Mihailescu, Iulia Matei, Dana Stan, Carmen Aura Moldovan, Marian Ion, Ion Baciu
    更新日期:2017-10-24
  • Flow-batch analysis of clenbuterol based on analyte extraction on molecularly imprinted polymers coupled to an in-system chromogenic reaction. Application to human urine and milk substitute samples
    Talanta (IF 4.162) Pub Date : 2017-10-23
    Natalia González, Marcos Grünhut, Ivana Šrámková, Adriana G. Lista, Burkhard Horstkotte, Petr Solich, Hana Sklenářová, Carolina C. Acebal
    更新日期:2017-10-23
  • A new procedure for high precision isotope ratio determinations of U, Cu and Zn at nanogram levels in cultured human cells: what are the limiting factors?
    Talanta (IF 4.162) Pub Date : 2017-10-23
    Eduardo Paredes, Emilie Avazeri, Véronique Malard, Claude Vidaud, Richard Ortega, Anthony Nonell, Hélène Isnard, Frédéric Chartier, Carole Bresson
    更新日期:2017-10-23
  • Simultaneous grouping and ranking with combination of SOM and TOPSIS for selection of preferable analytical procedure for furan determination in food
    Talanta (IF 4.162) Pub Date : 2017-10-23
    Renata Jędrkiewicz, Stefan Tsakovski, Aurore Lavenu, Jacek Namieśnik, Marek Tobiszewski
    更新日期:2017-10-23
  • Copper sulfide nanoplates as nanosensors for fast, sensitive and selective detection of DNA
    Talanta (IF 4.162) Pub Date : 2017-10-23
    Dewen Wang, Qun Li, Zhicai Xing, Xiurong Yang
    更新日期:2017-10-23
  • 更新日期:2017-10-23
  • Immunosensing system for rapid multiplex detection of mastitis-causing pathogens in milk
    Talanta (IF 4.162) Pub Date : 2017-10-22
    Delia Juronen, Ave Kuusk, Kairi Kivirand, Ago Rinken, Toonika Rinken
    更新日期:2017-10-23
  • 更新日期:2017-10-23
  • Low-cost and Reagent-free Paper-based Device to Detect Chloride Ions in Serum and Sweat
    Talanta (IF 4.162) Pub Date : 2017-10-21
    Stefano Cinti, Luca Fiore, Renato Massoud, Claudio Cortese, Danila Moscone, Giuseppe Palleschi, Fabiana Arduini
    更新日期:2017-10-23
  • A High Sensitivity Biosensor to detect the presence of perfluorinated compounds in environment
    Talanta (IF 4.162) Pub Date : 2017-10-21
    Nunzio Cennamo, Luigi Zeni, Paolo Tortora, Maria Elena Regonesi, Alessandro Giusti, Maria Staiano, Sabato D'Auria, Antonio Varriale
    更新日期:2017-10-23
  • Simple and selective determination of 6-thioguanine by using polyethylenimine(PEI) functionalized carbon dots
    Talanta (IF 4.162) Pub Date : 2017-10-20
    Hongyan Zeng, Li Li, Yaping Ding, Qi Zhuang
    更新日期:2017-10-21
  • Detection of yeast Saccharomyces cerevisiae with ionic liquid mediated carbon dots
    Talanta (IF 4.162) Pub Date : 2017-10-18
    Jia-Li Wang, Ji-Yuan Teng, Te Jia, Yang Shu
    更新日期:2017-10-19
  • Chiral recognition of tryptophan enantiomers using chitosan-capped silver nanoparticles: scanometry and spectrophotometry approaches
    Talanta (IF 4.162) Pub Date : 2017-10-18
    Marzieh Jafari, Javad Tashkhourian, Ghodratollah Absalan
    更新日期:2017-10-18
  • Comparison of Common Components Analysis with Principal Components Analysis and Independent Components Analysis: Application to SPME-GC-MS Volatolomic Signatures
    Talanta (IF 4.162) Pub Date : 2017-10-18
    Jihéne Bouhlel, Delphine Jouan-Rimbaud Bouveresse, Said Abouelkaram, Elisabeth Baéza, Catherine Jondreville, Angélique Travel, Jérémy Ratel, Erwan Engel, Douglas N. Rutledge
    更新日期:2017-10-18
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.
化学 · 材料 期刊列表