Reduction of graphene oxide with sulfuric and phosphoric acids and investigation of its electroanalytical applications

This study concerns with the synthesis of high-quality graphene with the water elimination reaction in the presence of sulfuric and phosphoric acids (H2SO4?G and H3PO4?G). Graphene was synthesized with single-step reduction method which was not encountered in the literature before. This method called as the acidic method has big advantages such as absence of toxic products, ease of purification and high-quality graphene yield. Graphene synthesized were characterized by the spectroscopic methods and used for the fabrication of modified electrodes. The modified graphene electrodes developed were used in the electrochemical determination of biologically significant compounds such as dopamine (DA) and uric acid (CA) by the use of cyclic voltammetry (CV) and differential pulse voltammetry (DPV). H2SO4?G and H3PO4?G electrodes showed a high electrocatalytic activity towards the oxidation of both DA and UA. The detection limits of DA carried out with both H2SO4?G and H3PO4?G electrodes were found to be 0,2214 and 0,0916 µM. The corresponding values for the analysis of UA were 0,2710 and 0,1421 µM (S/N=3).The suitability of the modified graphene electrodes developed were determined by the use of real samples. The data showed no significant difference between the real and the measured values in 95% confidence level. The results showed that the modified graphene electrodes developed gave highly sensitive, stable and selective behavior towards the oxidation of DA and UA which were very promising for an alternative electrode for routine analysis.