▎ 摘　　要

We report for the first time sinapic acid (SA) sensing based on nanocomposite comprising electrochemically tuned gold nanoparticles (EAuNPs) and solvothermally reduced graphene oxide (rGO). The synthesized EAuNPs, rGO, and EAuNPs-rGO nanocomposite were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), particle size analysis, and Raman spectroscopy. A proof-of-concept electrochemical sensor for SA was developed based on synthesized EAuNPs-rGO nanocomposite, which was characterized by electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The developed sensor detected SA with a linear dynamic range (LDR) between 20 mu M and 200 mu M and detection limit (DL) of 33.43 (+/- 0.21) nM (RSD<3.32 %). To show the useful purpose of the sensor probe in clinical applications, SA was detected in human urine samples, which showed the percentage recovery between 82.6 % and 92.8 %. Interferences due to various molecules such as L-cystine, glycine, alanine, serum albumin, uric acid, citric acid, ascorbic acid, and urea were tested. Long-term stability of the sensor probe was examined, which was found to be stable up to 6 weeks. The sensor fabricated using EAuNPs-rGO nanocomposite has many attractive features such as; simplicity, rapidity, and label-free detection; hence, it could be a method of choice for SA detection in various matrices.