电解质的加入对Au@Ag纳米粒子SERS效应的影响

Influence of Addition of Electrolyte on SERS Activity of Gold Core Silver Shell Nanoparticles

通过先采用Frens法制备粒径约为12nm的Au NPs,以此为基础通过以抗坏血酸为还原剂,采用种子生长法成功制得Au@Ag纳米粒子,通过UV-Vis表征发现具有很好的稳定性。接着以4-巯基吡啶(4-MPy)分子为探针,考察了加入电解质的量、加入顺序、电解质的阳离子、电解质的阴离子对纳米粒子SERS活性的影响,并结合UV-Vis光谱进行了分析。结果显示加入电解质的量一般会有一个最佳值,加入阳离子种类以及加入顺序对纳米粒子SERS活性影响不是很明显。不同阴离子的加入对纳米粒子影响不同,这主要是由于阴离子的加入使溶胶发生聚集以及阴离子与Au@Ag纳米粒子银表面相互作用的结果。

Gold nanoparticles with particle size about 12 nm Au NPs were prepared by Frens method first,by using ascorbic acid as reducing agent.Gold core silver shell nanoparticles were prepared by seed mediated growth method.By using p-mercaptopyridine(p-MPy)as probe molecule,we studied SERS activity of nanoparticles by adding electrolytes with different amount,or different kinds or addition order.The UV-Visible spectroscopic results showed that the amount of added electrolytes generally have an optimum value.The effects of species of adding cationic and addition order on SERS activity of nanoparticles were not very obvious.Adding different anions had different effects on nanoparticles,this was mainly due to nanoparticle aggregation and surface interaction of anions with Au@Ag nanoparticles.