Green synthesis, characterization of Radix Hedysari-mediated silver nanoparticles and their use for sensitive colorimetric detection of Pb2+ in the Yellow River medium

In this study, a safe, rapid, and environment-friendly green synthesis of silver nanoparticles using the alcohol extract of Radix Hedysari (RH-AgNPs) was developed, the alcohol extract of Radix Hedysari (RH) acted as the reducing agent, stabilizer, and modifier. The main components of RH were determined using high-performance liquid chromatography (HPLC). The particle size and morphology of RH-AgNPs were optimized and characterized by a series of techniques. The size distribution, zeta potential, element distribution, and crystalline nature of RH-AgNPs were all determined. It was indicated that RH-AgNPs showed great sensitivity for lead ion (Pb2+) detection with a limit of detection (LOD) of 1.5 mu M with a wide range of 10-500 mu M. The selectivity was also explored for common metal ions. RH-AgNPs were then applied to the detection of Pb2+ in spiked Yellow River samples, and the possible mechanism is based on the crosslinking reaction between the hydroxide radical, carboxylate radical and Pb2+.