A glassy carbon electrode modified with electrochemically reduced graphene for simultaneous determination of guanine and adenine

Abstract

In this paper, the direct electrochemical oxidation and differential pulse voltammetry (DPV) determination of guanine and adenine are studied by using an electrochemically reduced graphene oxide (er-GO) modified glassy carbon electrode (er-GO/GCE). Compared to the GCE and the GO/GCE, the as-prepared er-GO/GCE shows excellent electrocatalytic activity towards guanine and adenine, with an increase of oxidation current along with a negative shift of oxidation potential. Using the as-prepared er-GO/GCE, the simultaneous determination of guanine and adenine is successfully carried out, and the detection limits (based on S/N of 3) for guanine and adenine are 1.5 × 10⁻⁷ mol L⁻¹ and 2.0 × 10⁻⁷ mol L⁻¹, respectively. In addition, this er-GO/GCE exhibits a high selectivity, reproducibility and stability, and also can be used for the detection of guanine and adenine in the thermally denatured calf thymus DNA and urine, showing its promising application in the analysis of real samples.