Molecularly imprinted hornlike polymer@electrochemically reduced graphene oxide electrode for the highly selective determination of an antiemetic drug

Abstract

Robust, highly selective, and sensitive sensor devices are in high demand for the detection of bioactive molecules. Bioactive molecules are quantified by the electrochemical approach in the presence of other interference species, presenting a significant challenge to researchers. In this study, molecularly imprinted polymer (MIP) was prepared using the electrochemical method in a methanol/water solution mixture. The MIP on the electrochemically reduced graphene oxide (ERGO) surface exhibited hornlike morphology in contrast to the bare GC obtained, forming irregular bulky structures with a size range of 0.8-2.1 μm. The domperidone (DP) binding/extraction from MIP@ERGO was studied using ex situ Fourier transform infrared and X-ray photoelectron spectroscopy. The hornlike MIP@ERGO/GC revealed a higher heterogeneous electron transfer rate constant and DP antiemetic drug oxidation current response compared with the MIP/GC and non-imprinted polymer (NIP/GC) electrodes. The hornlike MIP@ERGO/GC electrode fabrication was optimized in terms of the pyrrole polymerization cyclic voltammetry cycle number, monomer/template concentration, and incubation times. The fabricated MIP@ERGO/GC electrode demonstrated a wide concentration range of DP detection (from 0.5 to 17.2 μM), and the limit of detection was found to be 3.8 nM, with a signal-to-noise ratio of 3. Moreover, the MIP@ERGO/GC electrode had excellent DP selectivity (with an imprinting factor of 4.20), even in the presence of ascorbic acid, uric acid, dopamine, xanthine, gelatin, glucose, sucrose, l-cysteine, folic acid, K⁺, Na⁺, Ca²⁺, CO₃^2-, SO₄^2-, and NO^3- interferences. The MIP@ERGO/GC electrode was tested on a human urine sample, and DP recovery ranges between 98.4% and 100.87% were obtained.

Keywords: Differential pulse voltammetry; Domperidone; Imprinting factor; Molecularly imprinted polymer; Polypyrrole.