Light-Controlled Photochemical Synthesis of Gelatin-Capped Gold Nanoparticles for Spectral Activity and Electro-oxidation of Quercetin

摘要

Gelatin-capped gold nanoparticles (GEL-AuNPs) were prepared through the in situ reduction of tetrachloroauric acid (HAuCl4) in gelatin solution under UV light without external reducing agents. The effect of HAuCl4 concentration and reaction time intervals were monitored by using UV/Vis spectroscopy. The hydrophilic and biocompatible nature of the GEL-AuNPs composite was studied in terms of their optical activity and electrocatalytic activity toward quercetin (QR). The optical spectra showed a decrease in the absorbance and enhancement in fluorescence of QR as a function of AuNPs, owing to the interaction between QR and GEL-AuNPs. The spectral changes of QR may be caused by hydrogen-bond formation between the amine groups in GEL-AuNPs and -OH and/or carbonyl groups in QR. In addition, the GEL-AuNPs exhibited excellent electrocatalytic activity towards QR oxidation. The DPV results displayed a good linear response range over the concentrations of QR (0.02 to 34.5 mu M) with a detection limit of 1.9 nM. Moreover, GEL-AuNPs could be utilized for the determination of QR in onion and apple samples for practical applications with satisfactory recoveries.