类毛线团表面银微球的制备及其表面增强拉曼散射性能研究

以低分子量聚丙烯酰胺（PAM）为模板，通过液相化学还原法首次制备了类毛线团表面银微球，并采用扫描电子显微镜（SEM）、X射线衍射（XRD）及氮气吸附法对银微球形貌及分散性进行表征。结果表明，微球是由纳米片有序组装而成的介孔材料，表面遍布棱角和狭缝。考察了PAM分子量、硝酸银浓度及还原体系pH值变化对银球结构的影响，并对类毛线团表面的形成过程进行了阐述。将银球用作表面增强拉曼散射（SERS）检测基底，可显著地增强罗丹明B（Rh B）分子的拉曼信号强度，能够检测出浓度低至10^-16mol/L的Rh B。

Preparation and surface-enhanced Raman scattering activity of silver microspheres with woolen-ball-like surfaces

Silver microspheres with woolen-ball-like surfaces have been prepared by a chemical reduction method using low molecular weight polyacrylamide (PAM) as the surfactant. The morphology and dispersion of the product were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and nitrogen adsorption measurements. The results showed that the silver microspheres with numerous edges and corners over their surfaces were mesoporous materials, and consisted of various low-dimensional nanosheets. Varying the molecular weight of PAM, the concentration of silver nitrate and the pH value of the reduction system all had an impact on the silver structures. The probable growth process of the woolen-ball-like surface is presented. These silver substrates significantly amplified the Raman signals of rhodamine B (Rh B) in surface enhanced Raman scattering (SERS) spectroscopy. SERS showed that the detection limit for Rh B was as low as 10^-16mol/L.