Search

The development of high-efficiency and cost-effective difunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are highly attractive to fulfill the practical water electrolysis. Herein, a novel low-cost difunctional cobalt-nickel sulfide (Co

The low specific surface area and low charge transfer efficiency of conventional graphite carbon nitride (g-C

The development of bifunctional electrocatalysts with remarkable activity is highly desired for optimal application in overall water splitting, yet challenging. Herein, a unique CoNiP/NF catalyst with advanced feature of hollow well-integration nanostructure on porous Ni foam substrate is reported. Uniform and well-designed 2D cobalt‐based MOF nanosheet are prepared through a simple room temperature static growth, and then the 2D nanosheet arrays are converted into porous 2D nanosheets assembled by 3D microspheres due to ion-exchange and etching process with an additional phosphating. The as-obtained CoNiP/NF nanostructure arrays integrate the advantages of 2D nanosheets and 3D microspheres, modulating the intrinsic electronic structure and further providing rich reaction active sites, which not only promote the permeations of electrolyte, but also promote the evolution/release of gas. When CoNiP/NF as a flexible electrode for electrolysis of water, the nanowall arrays electrode shows remarkable electrochemical performance toward HER and OER with only 147 and 234 mV overpotential at 10 mA cm−2, respectively, and excellent cycle capability. Moreover, it delivers a much lower cell voltage of 1.62 V to attain 10 mA cm−2 as superior bifunctional electrocatalyst. Density functional theory (DFT) calculations suggest that the advantages of porous structure can facilitate fast electron transfer and mass transport, further improve electrochemical ability. It can be desired that this work reveals a rational technique to design porous nano-catalysts for hydrogen economy.

The development of advanced nanomaterials for the highly efficient electrical detection of biological species has attracted great attention. Here, novel polypyrrole-Pluronic F127 nanoparticles (PPy-F127 NPs) with conducting and biocompatibility properties were synthesized and used to construct a L-lactic acid biosensor that could be applied in biochemical assays. The PPy-F127 NPs were characterized by transmission electron microscopy (TEM), elemental analysis and UV-vis spectroscopy. Lactate oxidase (LOx) structure variation on the PPy-F127 NPs was investigated by circular dichroism (CD). The cyclic voltammetric results indicated that LOx immobilized on the PPy-F127 NPs exhibited direct electron transfer reaction with a formal potential value (E(0)') of 0.154 V vs. SCE. Moreover, the biosensor had good electrocatalytic activity toward L-lactic acid with a wide linear range (0.015-37.5 mM) and a low detection limit of 0.0088 mM. The regression equation was I (μA) = 0.02353c (mM) + 1.4135 (R(2) = 0.9939). The L-lactic acid biosensor had a good anti-interference property towards uric acid (UA), ascorbic acid (AA), glucose and cysteine. The idea and method provide a promising platform for the rapid development of biosensors that can be used in the detection of biological species.

Sensitive determination of carcinoembryonic antigen (CEA) is very important in clinical research and diagnosis. Herein we report the design and synthesis of a new kind of immunosensor based on the benefits of hyperbranched structure. The hyperbranched polyester was grafted to the surface of indium tin oxides glass (ITO) electrode, and the grafting processes were characterized by attentuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). After CEA and horse radish peroxidase (HRP)-labeled antibody-conjugated AuNPs (HRP-Ab2-AuNPs) bioconjugates were immobilized on the surface of the hyperbranched structure-modified electrode, the optimized conditions of the above electrode were investigated. Moreover, the analytical performance of the proposed immunosensor showed a high sensitivity, a linear range from 0.01 to 80ng/mL with a low detection limit of 2.36pg/mL, and good selectivity for CEA. The designed immunoassay system holds great potential for ultrasensitive electrochemical biosensing of other analytes.

The surface-modification of paper substrates with functional layers is gaining increasing interest, both from academic and industrial research. In this case, the cellulosic paper (CP) surface was functionalized with zwitterionic poly-(3-dimethyl(methacryloyloxyethyl) ammoniumpropane sulfonate) (CP-g-P(DMAPS) via surface-initiated atom transfer radical polymerization (ATRP) technique for enhancing blood compatibility. An obvious increase in graft yield of the functional P(DMAPS) with polymerization time was observed. The new CP-g-P(DMAPS) produced was investigated for its hemocompatibility. The hemocompatibility studied including platelet and whole blood ceels adhesion tests, hemolysis assay, morphological changes of red blood cells (RBCs), coagulation time tests, and complement activation, platelet activation at the molecular level. Most assays had remarkable differences in the presence of the new zwitterionic CP, indicated the importance of the zwitterion for hemocompatibility of CP.