以琼脂糖凝胶为模板, 将预先制备好的胶体金颗粒负载在琼脂糖凝胶的网状结构中, 制备了琼脂糖凝胶/纳米金复合膜结构, 采用透射电子显微镜、 扫描电子显微镜、 紫外-可见-近红外光谱仪对复合膜的结构和光学性质进行了表征, 实验数据表明纳米金颗粒均匀的分散在琼脂糖凝胶膜上, 并且呈现出优异的光学吸收特性。基于琼脂糖凝胶的溶胀收缩特性和纳米金颗粒可调的表面等离子体共振吸收特性, 将琼脂糖凝胶/纳米金复合膜作为表面增强拉曼(SERS)基底材料, 研究了其对拉曼信号分子尼罗蓝A(NBA)的SERS检测效果。结果表明, 琼脂糖凝胶的多孔网状结构为纳米金颗粒的富集提供了良好的载体, 随着琼脂糖凝胶在空气中失水收缩, 纳米金颗粒间距离逐渐缩短, 产生动态的热点效应, 对拉曼信号分子具有良好的增强效应。

Agarose gel/gold nanoparticles hybrid was prepared by adding gold nanoparticles to preformed agarose gel. Nanocomposite structures and properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy(SEM)、 and UV-Vis-NIR absorption spectroscopy. Experimental data indicated a uniform distribution of gold nanoparticles adsorbed on agarose gel network. And the excellent optical absorption properties were shown. Based on the swelling-contraction characteristics of agarose gel and the adjustable localized surface plasmon resonance (LSPR) of the gold nanoparticles, the nanocomposites were used as surface enhanced Raman scattering (SERS) substrate to detect the Raman signal molecules Nile blue A. Results revealed that the porous structure of the agarose gel provided a good carrier for the enrichment of the gold nanoparticles. The gold nanoparticles dynamic hot-spot effect arising from the agarose gel contraction loss of water in the air greatly enhanced the Raman signal.