具有可调谐的LSPR和SERS性能的“爆米花”状Au@Ag核壳超结构的制备

摘要

In this work,a popcorn-like Au@Ag core-shell superstructure was synthesized using dopamine dithiocarbamate (DDTC)as reducing agent to control the discontinuous overgrowth of the Ag nanoparticles onto Au nanocubes (Au NCs).The popcorn-like nanoparticles exhibited tunable plasmon resonances over a spectral range in visible regions.And the thickness of hierarchical Ag shell was finely tuned in a range from 17 to 29 nm by simply varying the concentration of AgNO3 solution.Furthermore,these nanoparticles could assemble into monolayer films using liquid-liquid interface self-assembly technique,and the surface enhanced Raman spectroscopy (SERS)performances of the prepared monolayer films with different AgNO3concentration were evaluated using crystal violet (CV)as the probe molecule.Meanwhile,three different excitation laser wavelengths (532 nm,633 nm,785 nm) were employed to investigate the effect of different laser wavelengths on the SERS performance of different substrates.This work indicates that the popcorn-like Au@Ag core-shell superstructures possess tunable localized surface plasmon resonance (LSPR)and SERS properties,which enables them to have great application prospect in solar cells,catalysis,chemical sensing and other fields.%本文通过使用多巴胺二硫代氨基甲酸(DDTC)作为还原剂来控制银纳米颗粒以异相成核的生长模式在金立方表面进行生长,合成出“爆米花”状的金银纳米超结构.这种结构的纳米颗粒在可见光区表现出可调谐的等离子体共振特性,并且通过改变硝酸银的浓度能够精细的调节银层的厚度.此外,使用液液界面自组装技术将纳米颗粒组装成单层膜,然后将结晶紫作为探针分子来研究纳米颗粒的表面增强拉曼散射特性(SERS)和银层厚度之间的依赖关系.并系统的研究了三种激发波长对SERS基底的响应.结果 表明“爆米花”状的金银核壳超结构具有可调节的局域表面等离子体共振(LSPR)和SERS特性,在太阳能电池、催化、化学传感等领域具有广阔的应用前景.