One-pot synthesis of a graphene oxide coated with an imprinted sol–gel for use in electrochemical sensing of paracetamol

Abstract

A route is described for the preparation of a composite consisting of graphene oxide and a molecularly imprinted sol–gel polymer (GO/MIPs) through one-pot room temperature polymerization in aqueous solution. The material was obtained by mixing graphene oxide with the monomers (phenyltriethoxysilane and tetramethoxysilane) and the template paracetamol, followed by sol–gel copolymerization and extraction. The monomer and template concentrations and the incubation time were optimized. The composite was characterized by FTIR, TGA, XRD, Raman spectroscopy and SEM. It was then deposited as a thin film acting as a molecular recognition element on a glassy carbon electrode to obtain an electrochemical sensor for paracetamol. The electrode displayed an excellent recognition capacity toward paracetamol compared to its analogs. The peak current is linearly proportional to the concentration of paracetamol in the 0.1 μM to 80 μM range, and the detection limit is 20 nM (at an SNR of 3). Hence, this electrode possesses a wider response range and lower detection limit compared to most previously reported electrochemical sensors for paracetamol. It also exhibits excellent stability and has been successfully used to determine paracetamol in tablets and spiked human urine samples.