A Novel rGO-Decorated Molecularly Imprinted Polyacrylic Acid Graphite Electrode for the Detection of Quercetin in Food

An effective reduced graphene oxide (rGO)-decorated molecularly imprinted polyacrylic acid graphite electrode (M-AARGO@G) has been proposed in this present study for the selective detection of quercetin (QCN), a flavonoid, in real food samples. The primary goal of identifying and quantifying health-promoting compounds like QCN is to evaluate the overall quality of vegetables and fruits. The M-AARGO@G electrode is a cost-effective, reproducible, and stable electrode that has been created using acrylic acid (AA) as the monomer and QCN as the template on a graphite base for QCN detection in food samples. Ultraviolet-visible (UV-vis) spectroscopy and scanning electron microscopy (SEM) were applied to characterize the developed M-AARGO@G electrode material. A trielectrode system based on differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques was employed to assess the analytical performance of the synthesized electrode. Thorough analysis revealed that the electrode could exhibit two broad linearity windows (0.001–
$1~\mu $
M; 1–
$400~\mu $
M) with an acceptable lower limit of QCN detection (LOD) and limit of quantification (LOQ) of 0.13 and 0.43 nM, respectively. Additionally, this electrode has demonstrated high reproducibility, good stability, and high repeatability, with RSD values of 1.47%, 1.82%, and 1.17%, respectively. The effectiveness of the proposed electrode has been further investigated in real food extracts, namely, onion, oregano, and spinach, which highlighted high accuracy compared to the high-performance liquid chromatography (HPLC) method. Furthermore, the statistical results obtained from the t-test analysis were also satisfactory for the mean QCN concentrations present in the three real samples.