Design and Development of Ultrafast Sinapic Acid Sensor Based on Electrochemically Nanotuned Gold Nanoparticles and Solvothermally Reduced Graphene Oxide

Abstract

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 μM and 200 μM 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.