Rapid and sensitive electrochemical monitoring of paracetamol and its simultaneous resolution in presence of epinephrine and tyrosine at GO/poly(Val) composite modified carbon paste electrode

Abstract

Over the past few years physicists, chemists and material scientists showed a special interest on graphene and graphene oxide (GO) relative research. Recently, there is a sudden upsurge in the development of GO based sensors, which was due to their eminent properties like fast electronic transfer rate, large surface area, high stability and excellent conductivity nature, enabled them for the sensitive determination of different analytes. In our present investigation, L-Valine was electropolymerized onto the clear surface of carbon paste electrode (poly(Val)/CPE) with the help of cyclic voltammetry (CV) technique. Later GO was immobilised onto the surface of poly(Val)/CPE, which showed enhanced electrocatalytic activity towards the determination paracetamol (PC) in comparison with bare CPE, GO/CPE and poly(Val)/CPE respectively in 0.1 M phosphate buffer solution (PBS) of pH 7.0. The surface morphology of different modified electrodes was studied with the help of scanning electron microscopy (SEM). The limit of detection (LOD) and limit of quantification (LOQ) values for PC were determined with the help of differential pulse voltammetry (DPV) and were found to be as 0.29 μM and 0.96 μM respectively. The effect of pH, scan rate and concentration of PC was studied in detail. The electron transfer efficiency of different fabricated electrodes was studied by electrochemical impedance spectroscopy (EIS). The simultaneous resolution of PC, epinephrine (EP) and tyrosine (TY) was achieved with the help of DPV technique at GO/poly(Val)/CPE. The obtained results suggest that the fabricated composite chemical sensor GO/poly(Val)/CPE has satisfactory electroanalytical performance. The proposed investigation method was successfully applied towards the determination of PC in pharmaceutical and human serum samples.