Study On Electrochemical Sensors Based On Graphene/Transitional Metal Oxides

Cheap transitional metal oxides as a group of valuable catalysts,they have several advantages, such as good thermal stability, resistanceto poisoning, long life and high selective oxidation reactions. Graphene(GO) has not only high surface area, strong mechanical strength andhigh electrical conductivity, but also good biocompatibility as well aslow cost, which made biomolecules not only immobilize on electrodebut keep their activity well. Graphene has become one of the mostcompelling electrochemical biosensor material. In this paper, two kindsof graphene/transition metal oxides nanocomposites were synthesized,through hydrothermal method, and electrochemical sensors werefabricated based them. The results were satisfactory. The main contentsare as follows:(1) Cu2O/RGO nanocomposites were prepared through a mildhydrothermal reaction route using sodium citrate as reductant andstabilizers, and the morphology and crystal structure were characterized.It was found that the as-obtained Cu2O/RGO exhibit notable catalyticperformance toward direct oxidization of glucose. A novelnonenzymatic electrochemical sensor for glucose based on Cu2O/RGOwas constructed. And the possible electrocatalytic mechanisms ofCu2O/RGO toward glucose oxidization were proposed. The sensorexhibited fast amperometric response, low detection limit, highselectivity, good stability and wide linear range. The sensor was used inthe practical application of detection glucose in human blood serum.(2) The Cu2O/RGO exhibit notable catalytic performance towarddirect reduction of H2O2. A novel nonenzymatic electrochemical sensorfor H2O2based on Cu2O/RGO was constructed. The possibleelectrocatalytic mechanism of Cu2O/RGO toward H2O2reduction was proposed. The sensor exhibited fast amperometric response to H2O2witha high sensitivity of4.85μAmM1, low detection limit of7.28×107mol·L-1. Moreover, the sensor showed wide linear range, goodstability, highly selective.（3） CuO/RGO nanocomposites were synthesized by a facialhydrothermal method as well as a novel nonenzymatic electrochemicalsensor for glucose based on CuO/RGO was constructed. CuO/RGOexhibited high catalytic effect to glucose direct oxidation. The possibleelectrocatalytic mechanism of CuO/RGO toward glucose oxidation wasproposed.Moreover, the sensor showed good reproducibility, good stability,high anti-interference, etc. CuO/RGO/GCE electrode also hold severaladvantages, such as quick response, simple preparation, low cost and soon.