Green Synthesis and Characterization of Rosa roxburghii Tratt.-Mediated Gold Nanoparticles for Visual Colorimetric Assay of Tiopronin

This study used <i>Rosa roxburghii</i> Tratt. crude extract (RR) as a reducing, stabilizing, and modifying agent for the green synthesis of gold nanoparticles (RR-AuNPs) via the one-pot method for the first time and established a novel colorimetric sensor for detecting tiopronin. Initially, RR-AuNPs with a uniform particle size and stable dispersion were prepared using the reducing property of RR. Upon the introduction of tiopronin, the drug binds to the surface of RR-AuNPs through Au-S bonds and hydrogen bonds, inducing a significant aggregation of RR-AuNPs. The absorbance of the RR-AuNP solution exhibited a linear relationship with the tiopronin concentration in the range of 0.17 μM to 16.67 μM (y = 1.9157 - 0.0972x), with a detection limit of 0.19 μM. The colorimetric sensor was successfully applied to detect tiopronin in urine samples. Compared with other detection methods, this approach is simple to operate and has a high sensitivity, a wide linear range, and a low detection limit.