Papers by Author: Kun Wang

Abstract: Using TiO2-decorated graphene (TiO2-G) nanohybrids as the immobilized platform for redox protein, and selecting glucose oxidase (GOD) as model enzyme, the direct electrochemistry of GOD was investigated in this paper. By virtue of the synergetic effect between graphene and TiO2 nanoparticles, the direct electron transfer of GOD on the TiO2-G nanohybrids modified electrode was remarkably promoted with a rate constant of 3.24 s-1. Moreover, based on the decrease of the electrocatalytic response of the reduced form of GOD by dissolved oxygen, a glucose biosensor was developed, which showed a satisfactory analytical performance for glucose determination over an acceptable linear concentration range from 5×10−4 to 2×10−2 mol/L. All these results demonstrated the great significance of such TiO2-G nanohybrids for the immobilization of enzyme and other biomolecules.

Abstract: A novel reagentless H₂O₂ biosensor based on ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF₆) functionalized nano-gold as the biocompatible interface of Cytochrome C (Cyt c) by self-assembled method was proposed. The immobilized Cyt c showed direct electrochemistry and displayed an excellent electrocatalytic response to the reduction of H₂O₂ without the aid of any electron mediator. Under optimal experimental conditions, the as-prepared biosensor showed a wide linear response to H₂O₂ in the range of 0.23 µM to 3.0 mM with a detection limit of 0.12 µM (S/N = 3). The resulting biosensor can reached 95% of steady-state current within 5 s. The K^app_m value for H₂O₂ was found to be 1.2 mM.

Abstract: Magnetically separable copper phthalocyanine/Fe₃O₄ (CuPc/Fe₃O₄) core–shell nano- composites were prepared by an organic-inorganic complexation technique, which could effectively catalyze photodegradation of the model pollutant methylene blue (MB), using hydrogen peroxide as oxidant under visible light irradiation. Moreover, the as-prepared functional nanocomposites could be easily separated from the photodegradation system by using an external magnetic field, which still kept high photocatalytic activity after 5 time’s continual utilization.