Enhancing determination of quercetin in honey samples through electrochemical sensors based on highly porous polypyrrole coupled with nanohybrid modified GCE

A novel MIP/MIL-101 (Cr)/MoS 2 /GCE sensor was fabricated for the determination of quercetin (Qu), based on MIL-101 (Cr)/MoS 2 modified GCE , followed by molecularly imprinted polymer (MIP) immobilized on modified electrode. Nanoscale materials of MIL-101 (Cr) and MoS 2 as electrochemical sensor modifiers were synthesized via hydrothermal methods The physical characterizations of the prepared MIL-101 (Cr), MoS 2 and MIL-101 (Cr)/MoS 2 were examined by FTIR, XRD, BET and TEM. The influencing parameters controlling the performance of the prepared sensor were in detailed studied. Under the optimized conditions, the electrochemical behavior of Qu at the MIP/MIL-101 (Cr)/MoS 2 /GCE sensor was investigated by using differential pulse voltammetry (DPV) method. The proposed sensor possessed desirable linear relationship between the peak currents and the Qu concentrations. Two linear concentration ranges can be observed at the MIP/MIL-101 (Cr)/MoS 2 /GCE sensor in the ranges of 0.1 to 10.5   μM and 10.5 to 700   μM, with a detection limit of 0.06   μM in phosphate buffer solution (PBS, pH   =   3.5) (S/N   =   3). Additionally, the MIP sensor presented excellent reproducibility, stability and selectivity. Furthermore, the imprinted sensor was also successfully applied for the determination of Qu in honey samples and received satisfactory recoveries.