采用微波法合成银纳米颗粒,通过化学自组装技术将银纳米颗粒吸附在玻璃基片上,制备了银纳米颗粒的局域表面等离子体传感器。在纯水中,紫外可见光消光谱表明局域表面等离子体共振位于428nm处。随外界折射率增加,共振峰发生红移,其折射率灵敏度达到(173±6)nm/RIU。在350℃温度下退火处理后,改变银颗粒在基片上的形貌,峰位发生约65nm的红移,灵敏度下降约20%。理论分析表明,银纳米颗粒形状和基底的相互作用影响折射率传感的波长响应和灵敏度特性。
Ag nanoparticles are prepared by microwave synthesizing method and absorbed on the glass slide by self-assembling technology. Thus, the localized surface plasmon resonant (LSPR) sensor is developed. UV-vis absorption spectrum shows that its LSPR peak is located at 428nm in pure water. The LSPR peak takes red shift when the refractive index of surrounding solution increases, and the sensitivity can arrive at (173±6) nm/RIU. After annealing at 350℃, the shape of Ag nanoparticles on the glass slide is changed. The LSPR peak shifts about 65 nm towards longer wavelength, and the sensitivity decreases with 20%. Theoretical analysis indicates that shape and substrate take important effect on the response of wavelength and the sensitivity for the refractive index sensor of Ag nanoparticles.