用2-巯基吡啶做分子探针SERRS光谱测定痕量金

SERRS Determination of Trace Gold(Ⅲ) Using 2-Mercaptopyridine as Molecular Probe

以PEG10000和柠檬酸三钠做稳定剂,硼氢化钠作还原剂,制备稳定的纳米银溶胶。在pH6.6的磷酸氢二钠-磷酸二氢钠缓冲溶液和氯化钠的存在下,纳米银形成较稳定的聚集纳米银溶胶,2-巯基吡啶(MP)吸附在纳米银聚集体表面并在1 002cm-1处有一个较强的表面增强共振拉曼散射(SERRS)峰。当加入Au3+时,可导致MP在1 002cm-1处的SERRS峰强度线性降低。在选定条件下,Au3+在0.5～3.0nmol/L与SERRS峰强度的降低值呈良好线性关系。据此建立了一种简单快速测定Au3+的SERRS定量分析方法。

A stable nanosilver solution was prepared,using PEG10000 as stabilizer and NaBH4 as reducer.In pH6.6 Na2HPO4-NaH2PO4 buffer solution containing PEG10000 and NaCl,nanosilvers were aggregated to form the stable aggregated-nanosilvers（ANS） that interact with the chromophore of 2-mercaptopyridine（MP） to obtain an ANS-MP surface-enhanced resonance Raman scattering（SERRS） probe,which exhibited a strong SERRS peak at 1 002 cm-1.When Au3＋ was added,the SERS intensity at 1 002 cm-1 decreased as the complex of Au3＋-MP formed and ANS particles precipitate to the bottom.In the optimal condition,the decreased SERRS intensity was linear to Au3＋ concentration in the range of 0.5～3.0 nmol/L.Based on this,a new sensitive SERS method has been proposed for the determination of trace Au3＋ in the synthetic sample with satisfactory results.