Diabetes mellitus, which has become a global public health problem in recent years, is increasing year by year and have become younger and younger. Monitoring of glucose concentration is very important for diabetics. In the past, enzymatic sensors (based on enzyme immobilization) have been widely used in glucose monitoring because of their rapid response, good selectivity and specificity. However, enzymatic glucose sensors can be readily influenced by external factors such as temperature, pH, and other electrochemical interfering substances. In order to solve these problems, non-enzymatic glucose sensors have been proposed as an alternative.

Graphene, known as a single layer of two-dimensional planar carbon atoms, is an excellent material with superior electronic properties, large surface area, zero band-gap energy, thermal stability and high electron mobility. These properties of graphene could be exhibited in composite materials. Graphene and/or graphene-based nanocomposite materials were used in many technological applications such as microelectronics, optoelectronics, catalysts/electrocatalysts, biosensor applications, etc. Graphene and/or graphene-based composites can generally be prepared on a large scale by using different techniques such as thermal, solvothermal, chemical and electrochemical reduction of graphite/graphene oxide. In this study, the synthesis of graphene was carried out by electrochemical reduction of graphite oxide. In order to obtain graphene-based composite material, both metal oxide and graphene structures were synthesized by one-step and one-pot electrochemical deposition on Au electrode surface. In electrochemical experiments, Au electrode, Pt wire and Ag/AgCl (3.5 M KCl) were used as the working electrode, the counter electrode, and reference electrode, respectively. During the formation of metal oxide nanoparticles on the electrode surface by cathodic electrochemical deposition, graphene oxide was simultaneously reduced to graphene structure. The composite material was characterized by using XRD, XPS and SEM techniques and the composite electrode was used as a non-enzymatic glucose sensor. In the electrochemical experiments for glucose sensor application, cyclic voltammetry and amperometry techniques were used. In addition to, the selective response of glucose on the composite electrode was also investigated.