A buckypaper decorated with CoP/Co for nonenzymatic amperometric sensing of glucose.

A freestanding and flexible buckypaper modfied with CoP/Co (CoP/Co-BP) is described. It has a sponge-like nanostructure and is shown to enable improved nonenzymatic sensing of glucose. The CoP/Co-BP was prepared by first depositing a uniform layer of ZIF- 67 crystals on BP, followed by two steps of pyrolysis treatment and phosphidation under an argon atmosphere. The morphology and structure of the material were characterized by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical properties were investigated by cyclic voltammetry and amperometric response. The amperometric sensor, best operated at 0.45 V (vs. SCE) at pH 13 has a linear range that extends from 0.5 µM to 1.8 mM of glucose, a 0.2 µM detection limit (at S/N = 3), and a sensitivity of 6427 µA mM-1 cm-2 in alkaline solution. This is mainly attributed to the synergistic effect between the highly active CoP nanostructure and BP which results in excellent conductivity. The uniformly distributed CoP nanoparticles in the network of BP prevent the formation of close-packed structure and facilitate electron transfer. The sensor has good selectivity and excellent long-term stability. It was applied to the determination of glucose in spiked human serum, and satisfactory results were obtained. Graphical abstractSchematic presentation of a freestanding and flexible buckypaper modfied with CoP/Co. It has a sponge-like nanostructure and exhibits improved catalytic activity toward glucose oxidation. This material was used for high-performance electrochemical glucose sensing.

Highly Porous NiCoSe4 Microspheres as High-Performance Anode Materials for Sodium-Ion Batteries.

Binary transition metal selenides have been more promising than single transition metal selenides as anode materials for sodium-ion batteries (SIBs). However, the controlled synthesis of transition metal selenides, especially those derived from metal-organic-frameworks with well-controlled structure and morphology is still challenging. In this paper, highly porous NiCoSe4 @NC composite microspheres were synthesized by simultaneous carbonization and selenization of a Ni-Co-based metal-organic framework (NiCo-MOF) and characterized by scanning electron microscopy, transition electron microscopy, X-Ray diffraction, X-Ray photoelectron spectroscopy and electrochemical techniques. The rationally engineered NiCoSe4 @NC composite exhibits a capacity of 325 mAh g-1 at a current density of 1 A g-1 , and 277.8 mAh g-1 at 10 A g-1 . Most importantly, the NiCoSe4 @NC retains a capacity of 293 mAh g-1 at 1 A g-1 after 1500 cycles, with a capacity decay rate of 0.025 % per cycle.

Preparation and antioxidant activities of oligosaccharides from Crassostrea gigas.

Oligosaccharides were prepared from Crassostrea gigas by hydrolysis of polysaccharide in C. gigas with peroxide oxygen (H2O2). The hydrolysates were cleared of protein, filtered, ultrafiltered and precipitated with absolute ethanol to give C. gigas oligosaccharides (CGOs). Factors affecting CGO yields, i.e., reaction time, temperature, and H2O2 concentration, were optimised as follows: 2.96h reaction time, 84.71°C reaction temperature, and 2.46% H2O2 concentration. Under these conditions, the maximum yield of CGOs reached 10.61%. The CGOs were then partially characterised by Fourier transform infrared spectroscopy, UV spectroscopy, monosaccharide composition, and antioxidant activities. Results indicate that CGOs possessed strong hydroxyl radical activity, 2,2-diphenyl-ß-picrylhydrazyl-radical-scavenging activity and reducing capacity at a concentration of 100µg/mL.