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In this work, an efficient and universal streptavidin-functionalized nitrogen-doped graphene (NG) was for the first time proposed and used to develop a highly sensitive electrochemical immunosensor for the detection of tumor markers. Transmission electron microscopy, electrochemical impedance spectrum, static water contact measurement, and cyclic voltammetry were used to characterize the streptavidin-functionalized NG platform and immunosensor. The biofunctionalized NG showed excellent hydrophilicity, larger specific surface area, and high electrochemical activity. These properties of the platform enhanced the loading capacity of proteins, and retained the bioactivity of the immobilized proteins, and thus remarkably improved the sensitivity of the immunosensor. Using carcinoembryonic antigen (CEA) as model analyte, the proposed immunosensor demonstrated a wide linear range of 0.02–12 ng mL −1 with a low detection limit of 0.01 ng mL −1 . The CEA immunosensor could be applied to detect human serum samples with satisfactory results. The streptavidin-functionalized NG material provided an universal and promising platform for the electrochemical immunosensing applications. [ABSTRACT FROM AUTHOR]

Chicken interleukin-4 (ChIL-4), which is released by activated type 2 helper (Th2) cells following their stimulation in vitro, is an important indicator for the study of cell-mediated immunity in chickens after infection or vaccination. In this work, the first ChIL-4 chemiluminescent (CL) immunosensor was developed via the immobilization of monoclonal ChIL-4 antibodies on a nitrogen-doped graphene (NG)-chitosan nanocomposite matrix. NG nanosheets were used for the first time in the CL immunoassay to provide a biocompatible microenvironment for the immobilized capture antibody. The ChIL-4 immunosensor was characterized systematically. The proposed immunosensor displayed a wide linear range from 0.05 to 70 ng mL −1 and a low detection limit of 0.02 ng mL −1 at a signal-to-noise ratio of 3. Compared to traditional assay methods, this system was more flexible, simple, rapid, and sensitive. Moreover, this CL immunoassay system had an excellent detection and fabrication reproducibility, a high specificity, an acceptable accuracy, and a high stability. This work enables the specific detection of ChIL-4 and the further study of its role in the immune responses of poultry. [ABSTRACT FROM AUTHOR]

A new label-free chemiluminescence (CL) immunoassay method is proposed for the cheap, convenient and sensitive detection of proteins through the co-immobilization of a capture antibody and horseradish peroxidase on a sensing interface. The specific immunoreaction on the interface effectively inhibits the enzymatic CL reaction, thus causing a decrease in CL signals. [ABSTRACT FROM AUTHOR]

We describe a highly sensitive electrochemical enzymatic glucose biosensor. A glassy carbon electrode was modified with cylinder-shaped titanium dioxide nanorods (TiO-NRs) for the immobilization of glucose oxidase. The modified nanorods and the enzyme biosensor were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry. The glucose oxidase on the TiO-NRs displays a high activity and undergoes fast surface-controlled electron transfer. A pair of well-defined quasi-reversible redox peaks was observed at −0.394 and −0.450 V. The TiO-NRs provide a good microenvironment to facilitate the direct electron transfer between enzyme and electrode surface. The biosensor has two linear response ranges, viz. from 2.0 to 52 μM, and 0.052 to 2.3 mM. The lower detection limit is 0.5 μM, and the sensitivity is 68.58 mA M cm. The glucose biosensor is selective, well reproducible, and stable. In our perception, the cylindrically shaped TiO-NRs provide a promising support for the immobilization of proteins and pave the way to the development of high-performance biosensors. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In this work, we reported an efficient platinum nanoparticles functionalized nitrogen doped graphene (PtNPs@NG) nanocomposite for devising novel electrochemical glucose biosensor for the first time. The fabricated PtNPs@NG and biosensor were characterized using transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, static water contact angle, UV–vis spectroscopy, electrochemical impedance spectra and cyclic voltammetry, respectively. PtNPs@NG showed large surface area and excellent biocompatibility, and enhanced the direct electron transfer between enzyme molecules and electrode surface. The glucose oxidase (GOx) immobilized on PtNPs@NG nanocomposite retained its bioactivity, and exhibited a surface controlled, quasi-reversible and fast electron transfer process. The constructed glucose biosensor showed wide linear range from 0.005 to 1.1 mM with high sensitivity of 20.31 mA M −1 cm −2 . The detection limit was calculated to be 0.002 mM at signal-to-noise of 3, which showed 20-fold decrease in comparison with single NG-based electrochemical biosensor for glucose. The proposed glucose biosensor also demonstrated excellent selectivity, good reproducibility, acceptable stability, and could be successfully applied in the detection of glucose in serum samples at the applied potential of −0.33 V. This research provided a promising biosensing platform for the development of excellent electrochemical biosensors. [ABSTRACT FROM AUTHOR]

Bovine interferon gamma (BoIFN-γ) released by T cells plays very important roles in early diagnosis of Mycobacterium tuberculosis (MTB) infections and control of bovine tuberculosis. In this work, a label-free electrochemical impedance immunosensor is for the first time developed for highly sensitive determination of BoIFN-γ. Cylinder-shaped TiO 2 nanorods are synthesized by a facile hydrothermal method, and show high surface area and good hydrophicility. The immunosensor is fabricated by the immobilization of BoIFN-γ monoclonal antibody on the TiO 2 nanorods modified glassy carbon electrode. The prepared TiO 2 and immunosensor are characterized using transmission electron microscopy, scanning electron microscopy, X-ray diffraction, contact angle measurement, cyclic voltammetry, and electrochemical impedance spectra. The BoIFN-γ concentration is measured through the relative increase of impedance values in corresponding specific binding of BoIFN-γ antigen and BoIFN-γ antibody. The relative increased impedance values are proportional to the logarithmic value of BoIFN-γ concentrations in a wide range of 0.0001 to 0.1 ng/mL with a low detection limit of 0.1 pg/mL. The developed BoIFN-γ immunosensor shows a 249-fold decrease in detection limit in comparison with current enzyme-linked immunosorbent assay. This study provides a new, simple, and highly sensitive approach for very potential application in early diagnosis of MTB infections and control of bovine tuberculosis. [ABSTRACT FROM AUTHOR]

A tetragonal columnar-shaped TiO2 (TCS-TiO2) nanorods are synthesized via a facile route for the immobilization of glucose oxidase (GOx). A novel electrochemical glucose biosensor is constructed based on the direct electrochemistry of GOx at TCS-TiO2 modified glassy carbon electrode. The fabricated biosensor is characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, electrochemical impedance spectra and cyclic voltammetry. The immobilized enzyme molecules on TCS-TiO2 nanorods retain its native structure and bioactivity and show a surface controlled, quasi-reversible and fast electron transfer process. The TCS-TiO2 nanorods have large surface area and provide a favorable microenvironment for enhancing the electron transfer between enzyme and electrode surface. The constructed glucose biosensor shows wide linear range from 5.0×10−6 to 1.32×10−3 M with a high sensitivity of 23.2mAM−1 cm−2. The detection limit is calculated to be 2.0×10−6 M at signal-to-noise of 3. The proposed glucose biosensor also exhibits excellent selectivity, good reproducibility, and acceptable operational stability. Furthermore, the biosensor can be successfully applied in the detection of glucose in serum sample at the applied potential of −0.50V. The TCS-TiO2 nanorods provide an efficient and promising platform for the immobilization of proteins and development of excellent biosensors. [ABSTRACT FROM AUTHOR]

Abstract: The quantitative detection of chicken interferon-γ (ChIFN-γ) released by T cells after in vitro stimulation is a good evaluation of cell-mediated immunity in chickens after infection or vaccination. This work reports a new flow-through the chemiluminescent (CL) immunoassay method for rapid and specific determination of ChIFN-γ at a level of sub-picogram per milliliter. The biocompatible graphene oxide nanosheet is introduced into CL immunoassay for highly efficient immobilization of capture antibody. The detection limit of the proposed method at a signal to noise ratio of 3 is 0.36pgml−1, which is 138-fold lower than the current lowest value of 50pgml−1 for ChIFN-γ. Coupling with a flow-through system, the whole immunoassay process can be completed within 25min. The resulting ChIFN-γ immunosensor shows excellent detection and fabrication reproducibility, good specificity and stability. The assay results of nature ChIFN-γ samples with the proposed method are in an acceptable agreement with the reference values. Compared to the present assay methods, this method is more flexible, simple, rapid and sensitive. The aim of this work is to demonstrate that the ultrasensitive, specific and rapid CL immunoassay format can become a very potential application for quantifying ChIFN-γ and further studying its role in immune response in poultry. [Copyright &y& Elsevier]

Highlights: [•] An ultrasensitive chemiluminescent (CL) immunoassay strategy was developed. [•] This assay was preformed based on a streptavidin-functionalized MWCNTs platform. [•] The sensitivity displays 7.9-fold increase compared to that without MWCNTs. [•] This method provides a promising approach for ultrasensitive CL immunoassay. [Copyright &y& Elsevier]

Abstract: Multi-walled carbon nanotubes (MWCNTs)–nanoflake-like SnS2 nanocomposite were designed for immobilization of glucose oxidase (GOx). The direct electrochemistry of GOx and glucose sensing at MWCNTs–SnS2 modified glassy carbon electrode were studied. Compared with single MWCNTs or SnS2, the MWCNTs–SnS2 film has larger surface area and provides a more favorable microenvironment for facilitating the electron transfer between enzyme and electrode surface. The properties of GOx/MWCNTs–SnS2 were examined by scanning electron microscopy, UV–vis spectroscopy, Fourier transform infrared spectroscopy and cyclic voltammetry. The immobilized enzyme on MWCNTs–SnS2 composite film retained its native structure and bioactivity and showed a surface controlled, reversible two-proton and two-electron transfer reaction with a apparent electron transfer rate constant of 3.96s−1. The constructed glucose biosensor exhibits wider linear range from 2.0×10−5 M to 1.95×10−3 M, much lower detection limit of 4.0×10−6 M at signal-to-noise of 3 and higher sensitivity of 21.65mAM−1 cm−2 than our previous nanoflake-like SnS2-based glucose sensor. The proposed biosensor has excellent selectivity, good reproducibility, and acceptable operational stability and can be successfully applied in the reagentless glucose sensing at −0.43V. This MWCNTs–SnS2 composite provides a new avenue for immobilizing proteins and fabricating excellent biosensors. [Copyright &y& Elsevier]

Urchin-like InS nanostructures were functionalized with multi-walled carbon nanotubes (MWCNTs) and deposited on a glassy carbon electrode (GCE) to obtain a new kind of sensor for dopamine (DA). The new electrode was characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, cyclic voltammetry and differential pulse voltammetry. It is found that the current response toward DA is significantly enhanced compared to that of a bare GCE or a GCE modified with MWCNTs. The peak separation between DA and ascorbic acid (AA) is up to 225 mV. The new electrode also has improved selectivity for DA over AA compared to the bare electrode. The new DA sensor has a wide linear range (0.5-300 μM), high sensitivity (594.9 μA mM cm) and low detection limit (0.1 μM). CNTs wrapped on urchin-like nanostructures remarkable improve its electrocatalytic activity and thus provide a promising strategy to develop excellent composite materials for electrochemical sensing. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: A novel urchin-like In2O3–chitosan modified glassy carbon electrode (GCE) is for the first time prepared. The direct electrochemistry of glucose oxidase (GOD) immobilized on the surface of modified GCE and biosensing are studied. The urchin-like In2O3 nanostructure-based matrix has large specific surface area and provides a favorable and biocompatible microenvironment for promoting the direct electron transfer between proteins and electrode surface. The properties of different modified electrode are characterized by scanning electron microscopy (SEM), electrochemical impedance spectra (EIS), UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry, respectively. The constructed glucose biosensor shows wide linear range (5.0×10−6 to 1.3×10−3 M), low detection limit (1.9×10−6 M), a Michaelis–Menten constant of 0.37mM. The proposed biosensor has good sensitivity, excellent selectivity, good reproducibility and stability. This urchin-like In2O3–chitosan matrix provides a new approach and efficient matrix for the direct electrochemistry of proteins and developing novel types of biosensors. [Copyright &y& Elsevier]

Abstract: A streptavidin functionalized capillary immune microreactor was designed for highly efficient flow-through chemiluminescent (CL) immunoassay. The functionalized capillary could be used as both a support for highly efficient immobilization of antibody and a flow cell for flow-through immunoassay. The functionalized inner wall and the capture process were characterized using scanning electron microscopy. Compared to conventional packed tube or thin-layer cell immunoreactor, the proposed microreactor showed remarkable properties such as lower cost, simpler fabrication, better practicality and wider dynamic range for fast CL immunoassay with good reproducibility and stability. Using α-fetoprotein as model analyte, the highly efficient CL flow-through immunoassay system showed a linear range of 3 orders of magnitude from 0.5 to 200ngmL−1 and a low detection limit of 0.1ngmL−1. The capillary immune microreactor could make up the shortcoming of conventional CL immunoreactors and provided a promising alternative for highly efficient flow-injection immunoassay. [Copyright &y& Elsevier]

Abstract: A novel biosensor is developed based on immobilization of proteins on nanoflake-like SnS2 modified glass carbon electrode (GCE). With glucose oxidase (GOD) as a model, direct electrochemistry of the GOD/nanoflake-like SnS2 is studied. The prepared SnS2 has large surface area and can offer favorable microenvironment for facilitating the electron transfer between protein and electrode surface. The properties of GOD/SnS2 are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry (CV), respectively. The immobilized enzyme on nanoflake-like SnS2 retains its native structure and bioactivity and exhibits a surface-controlled, reversible two-proton and two-electron transfer reaction with the apparent electron transfer rate constant (k s) of 3.68s−1. The proposed biosensor shows fast amperometric response (8s) to glucose with a wide linear range from 2.5×10−5 M to 1.1×10−3 M, a low detection limit of 1.0×10−5 M at signal-to-noise of 3 and good sensitivity (7.6±0.5mAM−1 cm−2). The resulting biosensor has acceptable operational stability, good reproducibility and excellent selectivity and can be successfully applied in the reagentless glucose sensing at −0.45V. It should be worthwhile noting that it opens a new avenue for fabricating excellent electrochemical biosensor. [Copyright &y& Elsevier]

Abstract: A novel system of series-wound immunosensing channels (SWIC) was proposed for automated chemiluminescent (CL) dual-analyte immunoassay by immobilizing respectively different capture antibodies on the inner walls of series-wound glass channels. This system could use a single enzyme as label to perform multiplex immunoassay in one fluid way. Using α-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as model analytes, the mixture including AFP, horseradish peroxidase (HRP)-labeled anti-AFP antibody, CEA and HRP-labeled anti-CEA antibody was introduced into the SWIC for carrying out the on-line incubation. Upon injection of CL substrate the CL signals from the two immunosensing channels were conveniently resolved and near-simultaneously collected with the aid of optical shutter. AFP and CEA could be rapidly assayed in the ranges of 1.0–100 and 1.0–80ng/ml with detection limits of 0.41 and 0.39ng/ml, respectively. The assay results of clinical serum samples were in an acceptable agreement with the reference values. This designed flow-through immunosensing system based on SWIC provided an automated, reusable, simple, sensitive and low-cost approach for multianalyte immunoassay. [ABSTRACT FROM AUTHOR]

Abstract: A novel immunoaffinity column used as an immunosensor for flow-injection chemiluminescent (CL) immunoassay was prepared by immobilizing antibody on carboxylic resin beads. The immunosensor could fast recognize and trap the immunocomplex of horseradish peroxidase (HRP)-labeled antibody and antigen, which was firstly formed with a micro-bubble accelerated pre-incubation process, to produce a sandwich immunocomplex. The HRP introduced in the immunoaffinity column could catalyze the CL reaction to produce enzyme-enhanced emission. With α-fetoprotein (AFP) as a mode, a flow-injection CL immunoassay was proposed. The whole assay for one sample, including the pre-incubation and the regeneration of immunoaffinity column, could be performed within 16min. The linear range was 1.0–80ng/ml with a correlation coefficient of 0.998 and a detection limit of 0.1ng/ml at a signal/noise ratio of 3. The intra- and inter-assay coefficients of variation at 20ng/ml AFP were 1.2% and 8.5%, respectively. The storage stability of the immunoaffinity column and the accuracy for sample detection were acceptable. This flexible, sensitive, low-cost, and rapid method is valuable for clinical immunoassay. [Copyright &y& Elsevier]

A simple and sensitive spectrophotometric method is described for determination of amoxicillin. The method is based on a nucleophilic substitution reaction to measure the pink compound produced by the reaction of amoxicillin with sodium 1,2-naphthoquinone-4-sulfonate in pH 9.00 buffer solution. The stoichiometric ratio of the compound is 1:1, and its maximum absorption wavelength is at 468 nm, e=3.91×10 3 L · mol -1 · cm -1 . The Beer's law is obeyed in the range of 0.8–120 µg · mL -1 of amoxicillin. The linear regression equation is A =0.041239+0.22128 C , with 0.9994 of a linear regression correlation coefficient. The detection limit is 2.0 µg · mL -1 , and average recovery is over 98.5%. This paper further optimizes the determination of amoxcillin compared to the previous methods, and the kinetic property and reaction mechanism are studied intensively. This proposed method has been successfully applied to the determination of amoxicillin in tablets and capsules. The results obtained by this method agreed well with those by the official method high pressure liquid chromatography (HPLC). [ABSTRACT FROM AUTHOR]

Abstract: Treatment of halides 5 with electrophilic alkenes 2 afforded the corresponding dihydrofurans 3 and 4 in the presence of 1, 4-diazabicyclo[2.2.2]octane (DABCO) with good to excellent yields and in a stereoselective manner in most cases. Moreover, the stereoisomers 3 and 4 could be easily transformed each other in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). [Copyright &y& Elsevier]

In this study, a new type of gold nano-bipyramids@CuZn bimetallic organic framework (AuNBPs@CuZn MOF) nanozyme with high peroxidase (POD)-like activity and surface enhanced Raman scattering (SERS) activity was constructed with a special core–shell structure, which can catalyze the oxidation of TMB (colourless and Raman-inactive) into ox-TMB (blue and Raman-active). An AuNBPs@CuZn MOF-enabling universal SERS and colorimetric dual-model bioassay was thus developed for biomolecules with excellent performance, and has promising application prospects in the biosensing fields. [ABSTRACT FROM AUTHOR]

Interferon gamma (IFN‐γ) released by T lymphocytes, plays an important role in immune regulation and is also an important biomarker for the early diagnosis of bovine tuberculosis. In this work, an electrochemical immunosensor based on gold nanoparticles (AuNPs)/chitosan composite was developed for highly sensitive determination of bovine IFN‐γ. AuNPs/chitosan composite shows high surface area and good hydrophilicity. The bovine IFN‐γ immunosensor was prepared by immobilizing IFN‐γ antibody on AuNPs/chitosan composite‐modified glassy carbon electrode. The immunosensors were characterized by scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry (CV). Using horseradish peroxidase (HRP)‐labeled IFN‐γ antibody as amplification probe, the concentration of bovine IFN‐γ can be monitored via the increasing current signal, which can be attributed to the specific immune binding between bovine IFN‐γ antigen and HRP‐labeled IFN‐γ antibody, as well as the efficient catalysis reaction between thionine and HRP with the presence of H2O2. The developed electrochemical immunosensor exhibited a wide linear range of 0.01 to 30 ng/mL, and low detection limit of 0.003 ng/mL with good specificity and stability. This study provides a simple and promising method for diagnosis of bovine tuberculosis, which can be expanded to determine other biomarkers. [ABSTRACT FROM AUTHOR]

The failure mechanism of TP347H austenitic heat-resistant steel tube serviced in boiler superheater in a 600 MW subcritical thermal power unit is presented in this paper. Through microstructure observation, energy-dispersive spectrometry analysis, and selected electron diffraction, the mechanism of TP347H superheater bend tube failure is found to be attributed to intergranular corrosion cracking, more M23C6 and primary NbC(N) phase precipitating and coarsening along the grain boundary and formation of high content of slip lines and α′-martensite structure. The α′-martensite kept the Kurdjumov–Sachs (K-S) orientation relationships with parent austenite phase (γ-parent), which generated in TP347H bend tube may be related to the deformation-induced martensite (DIM) during rolling and cold working. The α′-martensite nucleated mainly at the grain boundary intersection between the twin crystal and γ-parent and grew inwards along the twin band. The dislocation density at the intersection is larger, and the secondary NbC(N) phase inhibited the nucleation of α'-martensite. [ABSTRACT FROM AUTHOR]

Although some simple and rapid colorimetric methods have been developed to detect organophosphorus pesticides (OPs), the difficult extraction and easy denaturation of acetylcholinesterase (AChE) are still drawbacks needing to be overcome. Here, we propose a MOF nanozyme-mediated AChE-free colorimetric strategy for the direct detection of OPs. In the presence of OPs (pirimiphos-methyl as a model), the intense blue of oxidized 3,3′,5,5′-tetramethylbenzidine (TMB) becomes light due to the quenching effect of OPs towards hydroxyl radicals (˙OH) that are generated by the decomposition of H2O2 catalyzed by the Cu4Co6 ZIF nanozyme with excellent peroxidase (POD)-like activity. The developed colorimetric sensor exhibits assay performance and offers a universal and promising analysis strategy for detecting OPs in practical samples. [ABSTRACT FROM AUTHOR]

Herein, a "two-in-one" Ag@Au core–shell nanozyme probe inducing double-signal amplification has been developed to significantly elevate the sensitivity of SPR sensors via sandwich immunoassay. The Ag@Au core–shell nanozyme with intrinsic peroxide-like activity was demonstrated to catalyze a polymerization reaction leading to formation of polyaniline, allowing further improvement of detection performance of SPR immunosensor. The method demonstrated here offers a universal strategy for enhanced SPR detection and further expands the application of nanozymes. [ABSTRACT FROM AUTHOR]

Bio-activity conservation of biomolecules after immobilizing in nanomaterials has been a tough challenge, especially in biomedical applications. Herein, we developed a novel freezing-assisted reverse microemulsion method to encapsulate water-soluble enzymes in hollow mesoporous silica nanospheres (HMSNs) for maximumly maintaining enzyme bio-activity. Firstly, a low-temperature and ethanol-free synthesis was carried out, and glucose oxidase (GOx) as a model enzyme was encapsulated into HMSNs to obtain GOx@HMSNs. The TEM and SEM images showed a uniform sphere morphology of GOx@HMSNs with a large hollow cavity for GOx loading. The element mapping, FTIR spectrum and TGA curve further confirmed the effective physical encapsulation of GOx in HMSNs, which can maintain stable bio-activity as verified by the enzyme activity assay. In addition to the facile synthesis for avoiding enzyme-denaturation, the N2 adsorption–desorption curves further demonstrated that small mesopores on HMSNs for blocking enzyme leakage may be another important factor for conserving GOx activity. Finally, GOx@HMSNs as a biosensor significantly possessed a wider linear range of 0.06 mM to 2.61 mM with a low detection limit of 0.01 mM, indicating high sensitivity. Therefore, our synthesis method provides a promising approach for biomolecule immobilization with potent bio-activity and biosensor applications with superior sensitivity. [ABSTRACT FROM AUTHOR]

This work reports the development of a new efficient visible-light-driven composite photocatalyst comprising SnS 2 nanoflakes and conjugated polymer (CPVC) from the dehydrochlorination of polyvinyl chloride (PVC). The optimum synthesis conditions were explored to obtain the most efficient SnS 2 /CPVC composite photocatalyst. The formation of SnS 2 /CPVC nanocomposites was confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, high-resolution transmission electron microscopy, and elemental mapping characterization. The photocatalytic tests demonstrated that SnS 2 /CPVC nanocomposites exhibited not only far higher visible-light-driven photocatalytic activity than SnS 2 nanoflakes, but also good photocatalytic stability and reusability in the reduction of aqueous Cr(VI) under visible-light ( λ > 420 nm) irradiation. The mechanism underlying the improved photocatalytic efficiency of SnS 2 /CPVC nanocomposites was elucidated, based on comparison between the optical, photoelectric, and electrochemical properties of SnS 2 /CPVC nanocomposites and SnS 2 nanoflakes, as well as the matched electronic band structures between SnS 2 and CPVC. [ABSTRACT FROM AUTHOR]

An ultrasensitive multiplex surface-enhanced Raman scattering (SERS) immunoassay was developed using porous Au–Ag alloy nanoparticles (p-AuAg NPs) as Raman signal amplification probe coupling with encoded photonic crystal microsphere. p-AuAg NPs were synthesized and modified with the second antibody (Ab2) and Raman tag (mercaptobenzoic acid, MBA) to prepare a Raman signal–amplified probe. The high porosity of the p-AuAg NPs enables significant coupling of the localized surface plasmon resonance and thus abundant inherent hotspots for Raman signal enhancement. 3D-ordered silver nanoparticles–coated silica photonic crystal beads (Ag/SPCBs) were prepared as encoded SERS substrate for multiplex detection using their reflection peaks. The signal-amplified probe was used for multiplex detection of tumor markers carcinoembryonic antigen (CEA) and alpha fetoprotein (AFP). The wide linear ranges of 10−7–103 ng/mL for CEA and 10−4–103 ng/mL for AFP with detection limits of 1.22 × 10−8 ng/mL and 2.47 × 10−5 ng/mL for CEA and AFP at a signal-to-noise ratio of 3 were obtained. The proposed multiplex SERS immunoassay method displays ultrahigh sensitivity, wide linear range, and excellent specificity, which can be successfully applied to measure clinical serum samples with satisfactory results. The research provides a novel SERS signal enhancement strategy for the multiplex bioassay. [ABSTRACT FROM AUTHOR]

In this research, dual-strategy biosensing of glucose was proposed based on multifunctional CuWO4 nanoparticles (CuWO4 NPs), which were prepared for the application of electrochemical and colorimetric sensing of glucose. CuWO4 NPs show large specific surface area and good conductivity as well as excellent peroxidase-like activity. A sensitive and selective electrochemical glucose biosensor was fabricated with the immobilization of glucose oxidase (GOx) on a CuWO4 NP modified electrode for enhancing the direct electron transfer behavior. A wide linear range of 0.005–1.8 mM with a low detection limit of 1.5 μM and a high sensitivity of 28.02 mA M−1 cm−2 were achieved by using the electrochemical biosensor. Meanwhile, a colorimetric and visual glucose biosensor was constructed based on the GOx/CuWO4 cascade nanozyme, which shows a linear range of 0.05–1.0 mM with excellent selectivity. CuWO4 NPs as a promising matrix open up a dual-strategy biosensor for sensitive and selective detection of glucose. [ABSTRACT FROM AUTHOR]

Failure cause and service properties of 20Cr1Mo1VNbTiB bolts in a 660 MW supercritical thermal power unit have been studied. The bolts fractured with evidence of material aging. Chemical analysis, microstructure characterization, mechanical properties testing, and energy-dispersive spectrometry were used for the analysis. The creep cavity was found in the microstructure with material serviced under 566 °C for about 30000 h. Some creep cavities accumulate and interconnect to form intergranular cracks. The cracks expand under the torsional force and lead to fracture failure. The precipitated phase in 20Cr1Mo1VNbTiB mainly includes TiN(C), NbC, and Mo-rich carbides. TiN(C) was the square shape and distributed on the matrix. NbC was a fine spherical shape and mainly distributed in the crystal. The Mo-rich carbide was elliptic in shape and primarily distributed in the grain boundaries. The coarse TiN(C) precipitates were relatively stable during service. The size of TiN(C) does not change and cannot be eliminated by reheat treatment. More quantity and larger Mo-rich carbides precipitated at grain boundaries after service, which led to the impact energy decrease. To avoid the same fracture accident, the 20Cr1Mo1VNbTiB bolts are not recommended for use in supercritical units with a steam temperature of 566 °C and above. [ABSTRACT FROM AUTHOR]

Efficient urchin-like Pt nanoparticles@Bi2S3 (PtNPs@Bi2S3) composite materials were prepared by a composite soft template synthesis of urchin-like Bi2S3 and then the microwave-assisted growth of PtNPs onto the Bi2S3 nanostructure. For the first time, an accurate electrochemical glucose biosensor was fabricated via immobilizing glucose oxidase (GOx) on PtNPs@Bi2S3. The PtNPs@Bi2S3 composite was investigated via scanning electron microscopy, electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy, and cyclic voltammetry. The PtNPs@Bi2S3 composite provides a large surface area to load a large number of enzyme molecules, which maintains the biological activity. PtNPs loaded on Bi2S3 enhanced the conductivity and improved the direct electron transfer of the proposed biosensor with the synergistic effect. The fabricated electrochemical biosensor possesses high sensitivity, and a wide linear range from 0.003 mM to 0.1 mM and 0.1 mM to 1.9 mM. Moreover, the biosensor has outstanding stability, superior selectivity and good repeatability, which can be utilized to monitor the glucose level in practical human serum. The PtNPs@Bi2S3 composite supplies a special matrix for immobilizing proteins and potential for establishing other effective biosensors. [ABSTRACT FROM AUTHOR]

An ultrasensitive label-free electrochemical immunosensor was fabricated for quantitative detection of Lactobacillus rhamnosus GG (LGG). The N/O co-doped three-dimensional hierarchical porous graphitic (THPG) carbon was synthesized by a one-step synthesis of polyaniline hydrogel, and followed by simple carbonization and chemical activation procedures. Because of the unique structure design, the obtained THPG carbon networks possess an ultra-large specific surface area of 4859 m2 g−1 along with a class of highly graphitic carbons. The results offer an enormous surface area and excellent electrical conductivity for label-free electrochemical immunosensing of probiotic L. rhamnosus strain. Under optimal conditions, the immunosensor showed a good linear relationship between peak current and concentration of LGG (R2 = 0.9976), with a detection limit of 2 CFU mL−1. Furthermore, this label-free immunosensor also shows good specificity, long-term stability, and reliability, and could be applied to detect probiotic LGG in dairy products and drinks with satisfactory results. The present protocol was shown to be quite promising for practical screening and functional evaluation of probiotic products containing LGG. A ultrasensitive label-free electrochemical immunosensor based on THPG carbon was fabricated for detection of Lactobacillus rhamnosus GG. [ABSTRACT FROM AUTHOR]

Abstract: A mesoporous silica nanoshpere (MSN) was proposed to modify glassy carbon electrode (GCE) for the immobilization of protein. Using glucose oxidase (GOD) as a model, direct electrochemistry of protein and biosensing at the MSN modified GCE was studied for the first time. The MNS had large surface area and offered a favorable microenvironment for facilitating the direct electron transfer between enzyme and electrode surface. Scanning electron microscopy, transmission electron microscopy, UV–vis spectroscopy and cyclic voltammetry were used to examine the interaction between GOD and the MSN matrix. The results demonstrated that the immobilized enzyme on the MSN retained its native structure and bioactivity. In addition, the electrochemical reaction showed a surface controlled, reversible two-proton and two-electron transfer process with the apparent electron transfer rate constant of 3.96s−1. The MNS-based glucose biosensor exhibited the two linear ranges of 0.04–2.0mM and 2.0–4.8mM, a high sensitivity of 14.5mAM−1 cm−2 and a low detection limit of 0.02mM at signal-to-noise of 3. The proposed biosensor showed excellent selectivity, good reproducibility, acceptable stability and could be successfully applied in the reagentless detection of glucose in real samples at −0.45V. The work displayed that mesoporous silica nanosphere provided a promising approach for immobilizing proteins and fabrication of excellent biosensors. [Copyright &y& Elsevier]

Abstract: An ultrasensitive electrochemical method for simultaneous determination of lead and cadmium was first developed using the novel bismuth–Nafion-medical stone doped disposable electrode (an improved wax-impregnated graphite electrode). Through the synergistic sensitization effect of the resulting composite material, the disposable electrode showed remarkable electrochemical responses to lead and cadmium. The oxidation of the two metals produced two well-defined and separated square wave peaks at about −0.62V for Pb2+ and −0.85V for Cd2+, respectively. The effects of the amount of medical stone, concentration of Nafion, thickness of bismuth, pH of buffer solution, deposition potential, accumulation time, voltammetric measurement and possible interferences were investigated in detail. Under the optimal conditions, the fabricated electrode exhibited linear ranges from 2.0 to 12.0μgL−1 with detection limit of 0.07μgL−1 for lead and 2.0–12.0μgL−1 with detection limit of 0.47μgL−1 for cadmium. The assay results of heavy metals in wastewater with the proposed method were in acceptable agreement with the atomic absorption spectroscopy method. [Copyright &y& Elsevier]

Abstract: A new method has been established for the determination of dopamine hydrochloride (DPH) using sodium 1,2-naphthoquinone-4-sulfonate (NQS) and tetradecyl benzyl dimethyl ammonium chloride (Zeph). This method is based on the formation of a pink compound from the reaction of DPH, sodium 1,2-naphthoquinone-4-sulfonate and Zeph. The condensation reaction proceeds quantitatively in pH 9.40 buffer solution. The maximum absorption wavelength and the value of ɛ 491 were 491nm, and 7.51×103 lmol−1 cm−1, respectively, when the stoichiometric ratio of the reaction was 1:1:1. Beer′s law was obeyed in the range of 0.16–40mgl−1 of DPH. The data have been filled to a linear regression equation A =0.5781+0.0254 C (mgl−1), with a correlation coefficient of 0.9993. The detection limit is 0.12mgl−1, R.S.D. is 0.64% (40mgl−1, n =11), and average recovery is over 99.7%. This paper further improves the determination of DPH compared to the previous methods. The kinetic property and reaction mechanism have also been discussed. This proposed method has been successfully applied to the determination of DPH in injection and biological samples with satisfactory results. [Copyright &y& Elsevier]

A novel hedgehog-shaped bismuth sulfide (HS-Bi2S3) nanostructure was for the first time explored as an electrode material for biosensing. Using cetyltrimethyl ammonium bromide (CTAB)-trimellitic acid as a composite soft template, the HS-Bi2S3 nanostructure was synthesized by a hydrothermal route. Using glucose oxidase (GOx) as the model, the HS-Bi2S3 nanostructure was employed to immobilize GOx for the development of a sensitive electrochemical glucose biosensor. The characterization of HS-Bi2S3 and the biosensor was performed by scanning electron microscopy, X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy and cyclic voltammetry. The hedgehog-shaped nanostructure of Bi2S3 has a large specific surface area to trap a large number of enzyme molecules, and at the same time greatly enhances the direct-electron-transfer action of enzymes. The HS-Bi2S3-based biosensor shows a wide linear range of 0.005–1.7 mmol L−1 and a low detection limit of 1.6 μmol L−1 for glucose at −0.37 V, which presents much better assay performance in comparison with the glucose biosensor without HS-Bi2S3. The present electrochemical biosensor displays high selectivity, good repeatability and stability, which can be used to measure blood glucose in real serum samples. [ABSTRACT FROM AUTHOR]

An effective electrochemical immunosensor for detecting the liver cancer biomarker was developed based on the hedgehog-like Bi2S3 nanostructure, which was synthesized using novel CTAB-trimellitic acid as a composite soft template and thiourea as the sulfur source by a simple hydrothermal method with 20-fold sensitivity enhancement and one order of magnitude increase of linear range. The electrochemical immunosensor presented excellent performance, and could be applied to detect the cancer biomarker in clinical serum samples. [ABSTRACT FROM AUTHOR]

A novel nanorod-like MoS2 semiconductor nanostructure was synthesized through a simple two-step method. The nanorod-like MoS2 nanostructure was exploited as an electrode material to immobilize enzymes and for electrochemical sensing application. Characterization of the nanorod-like MoS2 nanostructure and the resultant biosensor was performed by scanning electron microscopy, Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, and cyclic voltammetry. Enzyme molecules loaded at the MoS2 nanostructure retained their native structure and bioactivity. The direct electron transfer of glucose oxidase at the MoS2 nanostructure coated glassy carbon electrode was enhanced greatly. At an optimal potential of −0.45 V, the electrochemical glucose sensor had wide linear ranges of 1.5 × 10−5–3.25 × 10−4 M and 3.25 × 10−4–1.43 × 10−3 M, and a low detection limit of 0.005 mM (S/N = 3) with a high sensitivity of 25.06 ± 0.5 mA M−1 cm−2. At the same time, the present biosensor showed excellent selectivity, reproducibility and stability for glucose. What's more, the biosensor was successfully applied to the determination of practical samples. [ABSTRACT FROM AUTHOR]

Gastric cancer is the third leading cause of cancer‐related deaths worldwide. Novel biomarkers circRNAs can play an important role in the development of gastric cancer as oncogenes or tumor suppressor genes. The purpose of this study was to clarify the relationship between the abnormal expression of multiple circRNAs and their prognostic value in gastric cancer patients through a meta‐analysis. We researched articles reporting the relationship between circRNAs and the prognosis of gastric cancer published in PubMed, Cochrane, Embase, Web of Science, Wanfang, CNKI, and VIP databases before 31 December 2019. Thirty‐five articles were selected for the meta‐analysis, involving 3135 gastric cancer patients. The total HR values (95% CI) of OS and DFS related to highly expressed circRNAs that indicated worse prognosis were 1.83 (1.64‐2.03; p < 0.001) and 1.66 (1.33‐2.07; p < 0.001), respectively. The total HR (95% CI) of OS and DFS related to highly expressed circRNAs that indicated better prognosis was 0.54 (0.45‐0.66; p < 0.001) and 0.58 (0.43‐0.78; p < 0.001), respectively. Two panels of five circRNAs predicted a more considerable HR value (circ_0009910, hsa_circ_0000467, hsa_circ_0065149, hsa_circ_0081143, and circDLST; and circSMARCA5, circLMTK2, hsa_circ_0001017, hsa_circ_0061276, and circ‐KIAA1244). The results of the meta‐analysis were 2.63 (2.08‐3.33; p < 0.001) and 0.39 (0.27‐0.59; p < 0.001) for OS, respectively. The two panels of dysregulated circRNAs can be considered as more suitable potential prognostic tumor biomarkers in patients with gastric cancer because of their larger HR values. [ABSTRACT FROM AUTHOR]

• The crack morphology and trend were basically the same. • The boss of blade root is worn seriously in case of the turbine axial offset of the unit with an anomalous are. • FEM analysis indicates that the upper part of the first tooth on the steam outlet side of the blade root is the maximum centrifugal stress part. • The leaf root not tightly installed is the main cause of the accident. An analysis of the fracture cause for a steam turbine blade root is conducted in this study. During the maintenance of a steam turbine, nineteen IP-6S (Intermediate Pressure 6th Stage) blades with root cracks were detected. The causes of blade cracking are analyzed through macroscopic inspection, magnetic particle testing, room temperature mechanical property testing, micro-hardness testing, chemical analysis, metallo-graphic analysis, scanning electron microscopy and energy spectrum analysis, as the blade static stress is simulated in this paper. The results showed that the chemical composition and mechanical properties of the blade leaves are qualified, and none abnormal corrosive substances are found in the crack initiation part. The numerical simulation result showed that the surface of the first tooth arc is the mostly stressed part of the root, and the stress level can be increased by a loosing installation. The main reason for the root cracking of the blade is that the gap between the blade root and the leaf groove becomes larger, which leads to the changes of the blade root contact mode, then the stress of the first tooth arc was further increased, finally the root and leaf groove wear is aggravated, and fatigue cracking occurs at the stressed first tooth. [ABSTRACT FROM AUTHOR]

We describe an automation-friendly chemiluminescent immunoassay method for sensitive and rapid determination of chicken interferon-γ at the sub-picogram per millilitre level based on the monoclonal antibody immobilized paramagnetic microspheres and flow-through system. [ABSTRACT FROM AUTHOR]

In this research, a novel manganese dioxide nanorod-anchored graphene oxide (MnO2 NRs/GO) composite was synthesized by a simple hydrothermal method for electrochemical sensing application. A highly sensitive electrochemical sensor for dopamine (DA) was constructed by modifying glassy carbon electrode (GCE) with MnO2 NRs/GO. The morphology and performance of the composite material and modified GCEs were investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and cyclic voltammetry (CV), respectively. The resultant MnO2 NRs/GO composite has a large electroactive area and shows excellent electrochemical activity toward DA. Under the optimal conditions, the DA sensor shows a linear response in the DA concentration ranges of 0.1 μM–0.08 mM and 0.08–0.41 mM with a low detection limit of 0.027 μM and a high sensitivity of 602.4 μA·mM−1·cm−2. The MnO2 NRs/GO composite provides a promising platform for the construction of a highly sensitive and selective sensor of DA. [ABSTRACT FROM AUTHOR]

In this research, we reported effective streptavidin-functionalized tin disulfide nanoflakes (SnS2 NFs) to develop an ultrasensitive electrochemical immunosensor for the bioanalysis of tumor markers. The streptavidin-functionalized SnS2 platform and immunosensor were characterized by scanning electron microscopy, electrochemical impedance spectroscopy, static water contact angle measurements and cyclic voltammetry. Biofunctionalized SnS2 NFs displayed a large specific surface area and outstanding hydrophilicity. These characteristics enhanced the loading efficiency and capacity of antibodies on the biosensing platform and ensured the biological activity of the immobilized protein biomolecules. Carcinoembryonic antigen (CEA) was chosen as the model analyte, and a wide linear range of 0.006–3.0 ng mL−1 with a low detection limit of 5 pg mL−1 for CEA was exhibited by the immunosensor. Human serum sample analysis was achieved through the CEA immunosensor with satisfactory results. Streptavidin-functionalized SnS2 NFs offer a potential platform for the expansion of electrochemical immunosensor applications. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis of novel nanosized reduced graphene oxide@polystyrene nanospheres (rGO@PS NSs) through an electrostatic interaction method, and further their exploitation for highly sensitive label-free electrochemical immunoassay applications. These rGO@PS NSs provide a universal and promising carrier platform to develop excellent biosensors for clinical screening and diagnostic applications. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotubes coated with cobalt(II) sulfide nanoparticles were prepared and used for immobilization of glucose oxidase (GOx) to obtain an electrochemical glucose biosensor. The nanocomposite was synthesized through an in-situ hydrothermal method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and electrochemical impedance spectroscopy. The results show that the nanocomposite possesses a large specific surface area and apparently enhances the direct electron transfer between GOx and the surface of the electrode, best at a potential near −0.43 V (vs. SCE). The immobilized GOx retains its good bioactivity even at a high surface coverage of 30 pmol cm−2. Under the optimum conditions. The biosensor exhibits a wide linear range (from 8 μM to 1.5 mM), a high sensitivity (15 mA M −1 cm−2), and a 5 μM detection limit (at S/N = 3). The sensor is selective, acceptably repeatable, specific and stable. [ABSTRACT FROM AUTHOR]

A titanium dioxide functionalized SnS2 nanocomposite was synthesized for the immobilization of glucose oxidase (GOx) to develop an enzymatic electrochemical glucose biosensor. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry were used to characterize the nanocomposite and the glucose biosensor. The TiO2–SnS2 composite shows a larger surface area and GOx entrapped in this matrix maintains excellent bioactivity and stability. The constructed glucose biosensor responds to glucose linearly over two concentration ranges of 0.008 to 1.13 mM and 1.13 to 5.53 mM at a working potential of −0.45 V. The biosensor exhibits a high sensitivity (18.9 mA M−1 cm−2), low detection limit (1.8 × 10−6 M) and good repeatability. The present biosensor has excellent selectivity and can be successfully applied for the detection of glucose in serum samples. The advantages of the glucose biosensor show that a TiO2–SnS2 nanocomposite provides a new avenue for immobilizing proteins and fabricating excellent biosensors. [ABSTRACT FROM AUTHOR]

Failure analysis of a fractured high strength bolt used in a MW Class wind turbine blade connection system was conducted to clarify the failure cause and to determine the prevention method. Applying detailed mechanical characteristics and metallurgical investigations, the bolts failure cause can be attributed to bending fatigue. Evidenced by the nut polished markings, insufficient tightening was considered as the important reason for the bolt failure. The thread microstructure indicated that the fractured bolt thread was rolled rather than machined. However, rolling induced cracks locating on the thread crest and non-uniformly distributed decarburized layer on the bolt thread root existed. Thus, it can be concluded that the bolt failure was caused by the insufficient tightening and improper manufacturing procedure. [ABSTRACT FROM AUTHOR]

Abstract Quantitative detection of multiple chicken cytokines is a good evaluation of cell-mediated immunity in chickens after disease infection or vaccination. However, current assay methods for chicken cytokines cannot meet the needs of clinical diagnosis due to unsatisfactory sensitivity and low assay throughput. Herein, a sensitive chemiluminescence (CL) imaging immunosensor array has been developed for high-throughput detection of multiple chicken cytokines. The chicken cytokines immunosensor array was prepared by assembling different cytokine capture antibodies onto a disposable silanized glass chip, where horseradish peroxidase and antibody-conjugated gold nanoparticles were used as multienzymatic amplification probe for CL imaging signal amplification. By using a sandwich assay mode, the amplified CL signals from each sensing array cell were collected for quantitation. Using chicken interleukin-4 and chicken interferon-γ as model cytokines, this novel multiplexed and amplified method demonstrated simultaneous measurement of the two chicken cytokines in the linear ranges of 0.008–0.12 ng/mL and 0.005–0.20 ng/mL, respectively, which yields limits of detection down to 2 pg/mL and 3 pg/mL. The CL imaging array method reported here also demonstrated high specificity, good repeatability, and high stability and accuracy, providing a novel multiplex immunoassay strategy for highly sensitive and high-throughput detection of chicken cytokines and further disease diagnosis in poultry. Graphical abstract A novel multiplex immunosensor array for sensitive and high-throughput detection of multiple chicken cytokines is for the first time developed based on highly-sensitive chemiluminescence imaging coupled with a multienzymatic signal amplification probe. Image 1 Highlights • Multiplex immunosensor array for chicken cytokines was proposed for the first time. • Multiple chicken cytokines were simultaneously detected by sensitive CL imaging system. • The multiplex cytokines immunoassay has much better performance compared with current methods. • This work provides a novel strategy for sensitive and high-throughput multiplex immunoassay. [ABSTRACT FROM AUTHOR]

We report a new concept of a chemiluminescence imaging nanozyme immunoassay (CINIA), in which nanozymes are exploited as catalytic tags for simultaneous multiplex detection of cytokines. The CINIA provides a novel and universal nanozyme-labeled multiplex immunoassay strategy for high-throughput detection of relevant biomarkers and further disease diagnosis. [ABSTRACT FROM AUTHOR]

DNA methylation is an epigenetic event involved in regulation of gene transcription during cell differentiation. DNA methyltransferases (DNMT) play a role in differentiation of neural stem cells into neurons. The aim of this study was to determine whether nerve growth factor (NGF) was involved in differentiation of mouse hippocampal neuronal cell line (HT22) as assessed by IncuCyte. Quantitative PCR and western blot were used to measure gene and protein expression of DNMT as well as the activity of DNMTs. Treatment with NGF was found to upregulate both gene and protein expressions as well as total activity of DNMTs in differentiating HT22 cells. Compared to undifferentiating cells, the percentage of differentiating cells at S phase increased significantly when incubated with NGF. In undifferentiated cells, NGF failed to induce gene and protein expressions and activity of DNMTs. Data demonstrate that differentiation of HT22 cells by exposure to NGF involve the activation of DNMTs pathway. [ABSTRACT FROM AUTHOR]

Effective enhancement of the separation and transfer of photogenerated electrons and holes of semiconductor photocatalysts is key to increase their photocatalytic efficiency. This study aims at improving the photocatalytic performance of visible-light-responsive, CdI 2 -type layered SnS 2 by employing good conductivity N-doped reduced graphene oxide (NRG) and polyaniline (PANI) as the receptors and transporters of photogenerated electrons and holes, respectively. PANI/SnS 2 /NRG ternary composites were prepared by a three-step method, and the optimum conditions for preparing the most efficient product were explored. The photocatalytic experiments demonstrated that the PANI/SnS 2 /NRG ternary composite prepared under the optimum conditions (PANI/SnS 2 /NRG-2%) had markedly higher photocatalytic activity than SnS 2 nanoplates, SnS 2 /PANI and SnS 2 /NRG binary composites in the reduction of aqueous Cr(VI) under the irradiation of visible-light (λ > 420 nm). Based on comparison of the photoabsorption, photoluminescence and electrochemical impedance properties of PANI/SnS 2 /NRG, SnS 2 /PANI and SnS 2 , it was thought that the coupling of SnS 2 with both PANI and NRG had synergistic effects in increasing the absorption of visible-light as well as the separation and transfer of photogenerated electrons and holes, which contributed to the exceptionally high photocatalytic activity of PANI/SnS 2 /NRG ternary composite. Moreover, it was discovered that the photocatalytic reduction of Cr(VI) over PANI/SnS 2 /NRG-2% was dominantly through the reduction by photogenerated electrons, whereas both photogenerated electron and superoxide anion radical (O 2 – ) reduction played important roles in the photocatalytic reduction of Cr(VI) over SnS 2 . Besides, the influences of photocatalytic testing conditions (including starting pH and concentration of Cr(VI) solution, and dosage of photocatalyst) on the efficiency of PANI/SnS 2 /NRG-2% in treatment of aqueous Cr(VI) were also examined. [ABSTRACT FROM AUTHOR]