利用化学方法合成纳米银,调节pH值,加入赖氨酸溶液,通过紫外光谱和动态光散射法研究pH对纳米银及纳米银-赖氨酸体系稳定性的影响,利用表面增强拉曼光谱考察赖氨酸与纳米银的相互作用方式。紫外光谱显示纳米银和纳米银-赖氨酸体系在pH值为5~10时,均具有较强的吸收峰；应用动态光散射测定了不同pH的纳米银及其赖氨酸体系的粒径及强度自相关函数,在pH值为5~10时,粒径分布均匀,DLS自相关曲线平滑,说明纳米银和纳米银-赖氨酸体系稳定性良好；SERS研究了pH为4、7、10时,赖氨酸在银粒子表面的吸附作用,体系出现比较明显的赖氨酸特征峰,当pH为4时,为 δ（NH3+) 的1444 cm-1谱峰和δ（COO-)的1576 cm-1,此时赖氨酸通过氨根和羧酸根共同与银纳米粒子发生相互作用,当pH为10时,NH3+ 发生去质子化,此时赖氨酸只出现COO-的伸缩振动在1576 cm-1处,说明此条件下赖氨酸以羧酸根吸附在银粒子表面。

The prepared silver nanoparticles synthesized by chemical method was bound with lysine at different pH values.The UV-Vis spectrum and dynamic light scattering methods were used to study the stability of Ag colloids and AgNPs-lysine system.The interaction of Ag nanoparticles and lysine was surveyed by SERS.The results showed at the pH value of 5~10,the UV-Vis spectra appeared strong adsorption peak,the particle size was uniform distribution and DLS intensity auto-correlation curve was smooth,which indicated that the system had good stability.The interaction of lysine binding to Ag nanoparticle surface was investigated by SERS.At the pH value of 4,the SERS band at 1440 cm-1 is assigned to δ(NH3+),and the band of 1576 cm-1 is assigned to δ (COO-),which tells the lysine adsorbs on the Ag surface through the interaction of the amino and carboxyl groups together.At the pH value of 10,the main characteristic Raman spectrum was δ（COO-） at 1576 cm-1,it demonstrated that the lysine was adsorbed on the surface of silver nanoparticles with the NH3+ group.