A disposable molecularly imprinted sensor based on Graphe@AuNPs modified screen-printed electrode for highly selective and sensitive detection of cyhexatin in pear samples

Abstract

A novel electrochemical sensor based on molecularly imprinted polymeric membrane as biomimetic recognition element was fabricated by electropolymerization of o-aminothiophenol (O-ATP) on gold nanoparticle/electrochemical reduction graphene oxide-modified screen-printed carbon electrode (AuNPs/ERGO-SPCE) for sensitive and selective detection of cyhexatin (CYT) pesticides. The sensor was constructed through self-assembly of O-ATP and CYT, following by the electropolymerization of O-ATP in the presence of CYT based on the hydrogen-bonding interaction. The obtained imprinted polymer film was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), fourier transforms infrared (FT-IR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimal condition, both the obtained imprinted sensors based on AuNPs/ERGO/SPCE presented satisfactory linearity with the certain concentrations of CYT and the limit of detection (LOD) can reach 0.20 ng mL−1. The modification of ERGO and AuNPs could generate synergistic effect to increase the sensitivity of the MIP sensor. The developed imprinted sensors exhibited excellent long-term stability and repeatability. Furthermore, the established method was successfully applied to the determination of CYT in pear samples.