▎ 摘　　要

An ultrasensitive electrochemical sensor to detect quercetin (QR) based on mercapto-beta-cyclodextrin functionalized reduced oxide graphene being noncovalently decorated by 1-pyrenebutyrate and gold nanoparticles (PB-rGO/TCD/AuNPs) was developed in this work. The obtained PB-rGO/TCD/AuNPs nanocomposite was characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM), which confirm that the PB-rGO/TCD/AuNPs nanocomposite was successfully synthesized. The new nanocomposite integrate high supramolecular recognition ability of TCD with the high conductivity and large surface area of PB-rGO/AuNPs and the performance of sensor for the PB-rGO/TCD/AuNPs modified glassy carbon electrode (PB-rGO/TCD/AuNPs/GCE) are dramatically improved compared with PB-rGO/TCD modified glassy carbon electrode (PB-rGO/TCD/GCE), PB-rGO modified glassy carbon electrode (PB-rGO/GCE) and bare GCE. Under optimum conditions, the linear response range for QR was from 0.005 to 0.4 mu M with a low detection limit of 1.83 nM. Meantime, this sensor shows high sensitivity and good stability and several other flavonoids do not interfere with the determination of QR. To further judge the practical value of this sensor, a satisfactory result was obtained for the determination of the real sample.