一种新型的通用的SERS基底-核壳结构纳米子

为了进一步来提高SERS基底和分子的普适性,本文采取了一种"借力"的方法,设计合成了金核过渡金属薄壳(Au@Pd,Au@Pt,Au@Ni,Au@Co)的核壳结构纳米粒子,借用底层高SERS活性的金核强的电磁场来增强过渡金属表面吸附分子的SERS信号,使得过渡金属表面的增强因子可达104-105。系统地开展了不同壳层厚度及相同壳层厚度下金核大小对SERS活性影响的研究,发现随着壳层厚的增加SERS活性迅速衰减,而且当金核为120-140 nm时可以得到最强的增强。

A New Versatile SERS Substrate-Core-Shell Nanoparticles

To further improve the generality of molecules and SERS substrates,we have employed a strategy of "borrowing SERS activity" that is to coat Au nanoparticles with ultra-thin film of various transition metals to form core-shell nanoparticles,such as Au@Pd,Au@Pt,Au@Ni,Au@Co.With the aid of the long-range effect of the enormous electromagnetic enhancement created by the high SERS-active Au core underneath,the originally low surface enhancement of the transition metal can be substantially improved giving total enhancement factors up to 104-105. The effects of the shell thickness and the Au core size on the SERS activity were systematically investigated.The SERS activity decreases dramatically with the increase of the thickness and the Au core with a size of 120-140 nm gives the maximal enhancement.