Simultaneous and sensitive detection of acetaminophen and valacyclovir based on two dimensional graphene nanosheets

•Green approach through electrochemical reduction and deposition of graphene oxide•rGO shows high activity toward the oxidation of valacyclovir and acetaminophen.•Extremely low detection limit for valacyclovir (1.34 nM) and acetaminophen (4.65 nM)•Testing with pharmaceutical tablets in blood serum plasma shows excellent recovery.

A highly sensitive electrochemical sensor, based on two-dimensional (2D) graphene nanosheets, for the simultaneous detection of acetaminophen and valacyclovir has been developed. This sensor was fabricated through the concurrent electrochemical reduction and deposition of graphene oxide (GO) onto a glassy carbon electrode (GCE) using cyclic voltammetry (CV). Both CV and differential pulse voltammetry (DPV) were employed to study the electrocatalytic properties of the electrochemically reduced graphene oxide (rGO) modified GCE to elucidate the oxidation behaviour of acetaminophen and valacyclovir. The electrodeposition cycle and concentration of GO toward the optimal performance of the prepared sensor were also investigated. This developed sensor exhibited excellent activity for the simultaneous electrochemical oxidation of acetaminophen and valacyclovir. A very low detection limit of 1.34 nM for the exclusive detection of valacyclovir, as well as a promisingly lower detection limit of 4.65 nM for acetaminophen was achieved through the simultaneous detection of acetaminophen and valacyclovir in a mixture. The developed electrochemical sensor was also tested for reproducibility, stability and potential interference capability, which showed an excellent performance. It was further verified utilizing commercially available pharmaceutical tablets in human serum with very high recovery rates, demonstrating a great potential application for pharmaceutical quality control, as well as bioavailability testing and drug monitoring in hospital laboratories.

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