Detection of syringic acid in food extracts using molecular imprinted polyacrylonitrile infused graphite electrode

Abstract

A highly sensitive, cost-effective, and reproducible electrochemical sensor has been developed using acrylonitrile (AN) molecularly imprinted polymer (MIP) over graphite (MIP-AN@G electrode) for the first time to detect phenolic compound, syringic acid (SA), in food extracts. The primary objective of the recognition of specific health-beneficial compounds like SA is to assess the overall quality of fruits and vegetables. Introducing UV–visible (UV–vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM), the characterization of the fabricated MIP-AN@G electrode material has been performed. To investigate the electrode’s analytical characteristics, a tri-electrode system employing differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques was used. Rigorous analysis revealed that the electrode could exhibit high repeatability, high reproducibility, reasonably good stability, and a wide linearity window from 10 μM to 100 μM concentrations with a satisfactory lower limit of SA detection (LOD) of 0.32 μM, and a lower limit of quantification (LOQ) of 1.06 μM. The sensor’s detection competence has been further tested in cauliflower, oregano, and black olives samples, and high accuracies of over 99% were achieved in each case when compared to the high-performance liquid chromatography (HPLC) analysis. Further, the t-test statistical analysis yields satisfactory results for the SA concentrations present in the three real samples.