Ai Shi-yun, Gao Ji-gang, Zhu Lu-sheng, Ma Zhi-jun, Li Xiao-chen
College of Chemistry and Materials Science, Shandong Agricultural University, Taian 271018, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2008 Sep;28(9):2126-9.
The development of reliable, eco-friendly processes for the synthesis of nanomaterials is an important aspect of nanotechnology today. One approach that shows immense potential is based on the in situ synthesis of noble metal nanocolloids using natural biological material such as silk fibroin. In the present paper, the nano-Ag/silk-fibroin colloids were prepared by in situ reducing AgNO3 with silk-fibroin at room temperature without any reducing agent. UV-Vis absorption, atomic force microscopy, fluorescence spectra and resonance scattering spectra were used to study the preparation process and characterization of the nanocomposite. It was found that the formative Ag nanoparticles were attributed to the tyrosine residues in the chains of silk-fibroin that act as reduction agent in the reduction course of AgNO3, and the Ag nanoparticles were uniformly embedded in silk-fibroin colloid, which possess good dispersity and stability and can be kept for a long period. The strength of fluorescence spectra increased after reaction of silk-fibroin with AgNO3 solution, showing that there was a strong chemical adsorption between silver nanoparticles and silk-fibroin, and a stable complex layer was formed in silver nanoparticles. Meanwhile the existence of silver nanoparticles in silk-fibroin was proved by resonance scattering spectra.
开发可靠、环保的纳米材料合成工艺是当今纳米技术的一个重要方面。一种显示出巨大潜力的方法是基于使用天然生物材料如丝素蛋白原位合成贵金属纳米胶体。在本文中，通过在室温下用丝素蛋白原位还原硝酸银而不使用任何还原剂制备了纳米银/丝素蛋白胶体。利用紫外可见吸收光谱、原子力显微镜、荧光光谱和共振散射光谱研究了该纳米复合材料的制备过程和表征。结果发现，形成的银纳米颗粒归因于丝素蛋白链中的酪氨酸残基，其在硝酸银的还原过程中充当还原剂，并且银纳米颗粒均匀地嵌入丝素蛋白胶体中，该胶体具有良好的分散性和稳定性并且可以长期保存。丝素蛋白与硝酸银溶液反应后荧光光谱强度增加，表明银纳米颗粒与丝素蛋白之间存在强烈的化学吸附，并且在银纳米颗粒中形成了稳定的复合层。同时，共振散射光谱证明了丝素蛋白中银纳米颗粒的存在。
