玻璃基底上不规则银纳米结构的生长及其光学性质的研究

以经过硅烷化后玻璃片为基底，之后吸附金纳米种子，采用柠檬酸钠为还原剂，在荧光灯照射条件下还原硝酸银，制备出基底表面具有银纳米粒子聚集结构的材料。采用透射电镜、扫描电镜和紫外可见分光光度计对产物的形貌和性质进行了表征，并考察银纳米粒子的形貌对其薄膜基底SERS活性的影响。结果表明：随着光照时间增加至16 h，金种子长大为平均粒径110 nm的不规则状多晶银纳米粒子，且出现双层粒子堆积。基底上纳米粒子的吸收光谱上出现了由银粒子的表面等离子体激元偶极子耦合引发的强烈吸收峰：随着光照时间的变化，耦合峰在600～813 nm波段内移动。光照时间为12 h后得到的SERS活性基底具有最强的SERS信号。

Preparation of silver nanostructure on glass substrates and their spectral properties

Silver nanostructures on the surface of glass substrate have been synthesized by small gold seeds with the assistance of Na3-citrate. The effect of surface morphology of thin films of silver nanoparticles degree on the SERS activity of the substrate was studied by transmission electron microscopy, scanning electron microscopy and UV-Vis spectroscopy. The results showed that the silver nanostructure of the substrates which finally grew up to 110 nm 16 hour irradiation took on irregular shape, and some of nanoparticles stacked to form bilayer. A new broad band appeared in the absorption spectra of the substrates due to the interparticle dipole-dipole coupling of surface plasmon resonance response of the triangular silver nanoplate particles, which red shifted 600~813 nm as the particles grow up, indicating the intensification of the coupling. The strongest SERS signal of SERS-Active Substrate was fabricated after 12 h.