Multi-Walled Carbon Nanotubes based Purine Electrodes for Electrochemical Detection of Benzene and its Derivatives using Differential Pulse Voltammetry

Multi-walled carbon nanotubes (MWCNT) based purine electrodes, prepared by immobilizing purine nucleosides over MWCNT coated graphite electrode were used for electrochemical detection of Benzene and its mono-, di- and polysubstituted derivatives. The film forming abilities of MWCNT coated graphite electrodes were studied using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV) by placing the electrodes in electrolyte containing redox couple. Differential Pulse Voltammetry (DPV) was performed to identify the relative change in the oxidation peak of the purine bases after its interaction with analyte. Under optimized conditions, calibration curves were obtained for the modified electrodes over various analytes using DPV and the detection limit was found to be 10 ng/ml of benzene and 30 ng/ml for benzene derivatives. The proposed purine based MWCNT biosensor exhibited stability, high reproducibility, selectivity and regeneration, making it a potential tool for electrochemical detection of Benzene and its derivatives in water based samples.