A Reduced Graphene Oxide-Based Electrochemical Dna Biosensor for the Detection of Interaction Between Cisplatin and Dna Based on Guanine and Adenine Oxidation Signals

Abstract

A glassy carbon electrode (GCE) was modified by electrochemically reduced graphene oxide (ERGO) for subsequent dsDNA immobilization. The interaction of cisplatin with dsDNA was studied at this modified electrode. Quantitative investigations were performed by adsorptive transfer stripping voltammetry (AdTSV) using differential pulse voltammetry (DPV). The morphology and structure of graphene oxide (GO) and ERGO modified GCEs (GO/GCE and ERGO/GCE, respectively) were characterized by UV-vis, FT-IR, Raman spectroscopy and cyclic voltammetry. Compared with the bare GCE and the GO/GCE, the ERGO/GCE exhibited excellent electrocatalytic activity towards the oxidation of dsDNA due to guanine and adenine groups, testified by high oxidation peak currents and decreased oxidation potentials. The interaction of micromolar concentrations of cisplatin with surface confined dsDNA was readily detected as inferred from the decrease of the voltammetric oxidation peaks of guanine and adenine. This trend was significantly greater at the ERGO/GCE compared to the GO/GCE. The interaction of cisplatin with dsDNA was also studied in solution phase by AdTSV with detection at the ERGO/GCE.