紫外光引发还原制备金溶胶及其SERS活性的研究

文章报道了一种用紫外光引发还原制备金溶胶的新方法,其还原过程经历了自由基机理。用紫外可见光谱观察了不同反应时间溶胶状态的变化。结果表明,光照反应2h时明显出现金溶胶粒子,7h后氯金酸基本转化完毕。同时,研究了稳定剂聚乙烯吡咯烷酮(PVP)的加入对还原过程的影响,结果表明,PVP的加入不仅稳定了溶胶,而且降低了反应速率。用SEM观察了溶胶粒子聚集体的形貌。最后以1,4-bis(4-vinylpyridyl)phenylene为探针分子研究了这种溶胶的SERS活性。

Preparation of Gold Colloid Induced by Ultraviolet Irradiation and Its Application in SERS

A gold colloid has been prepared by a UV-photoactivation technique.It is believed that photolytic radicals were formed to catalyzed the reduction procedure.The formation process of the gold colloid was investigated by UV-Vis spectroscopy.The results show that the colloidal particles were formed obviously when the irradiation time was 2 hours and the translation of HAuCl_4 was completed when it was 7 hours.We also investigated the stabilizing effect of a polymer stabilizer-Poly(vinylpyrrolidone).It can not only stabilize the colloidal particles but also slower the reaction velocity.Finally,SERS activity of the colloid was studied using 1,4-bis(4-vinylpyridyl) phenylene as probe molecule.SEM was used to investigate the morphology of the aggregation of colloidal particles.