Jonaki, Board of Radiation and Isotope Technology, Department of Atomic Energy, CCMB Campus, Uppal Road, Hyderabad 500 007, Andhra Pradesh, India.
Colloids Surf B Biointerfaces. 2011 Apr 1;83(2):291-8. doi: 10.1016/j.colsurfb.2010.11.035. Epub 2010 Dec 3.
An environmentally benign method for the synthesis of noble metal nanoparticles has been reported using aqueous solution of gum kondagogu (Cochlospermum gossypium). Both the synthesis, as well as stabilization of colloidal Ag, Au and Pt nanoparticles has been accomplished in an aqueous medium containing gum kondagogu. The colloidal suspensions so obtained were found to be highly stable for prolonged period, without undergoing any oxidation. SEM-EDXA, UV-vis spectroscopy, XRD, FTIR and TEM techniques were used to characterize the Ag, Au and Pt nanoparticles. FTIR analysis indicates that -OH groups present in the gum matrix were responsible for the reduction of metal cations into nanoparticles. UV-vis studies showed a distinct surface plasmon resonance at 412 and 525 nm due to the formation of Au and Ag nanoparticles, respectively, within the gum network. XRD studies indicated that the nanoparticles were crystalline in nature with face centered cubic geometry. The noble metal nanoparticles prepared in the present study appears to be homogeneous with the particle size ranging between 2 and 10 nm, as evidenced by TEM analysis. The Ag and Au nanoparticles formed were in the average size range of 5.5±2.5 nm and 7.8±2.3 nm; while Pt nanoparticles were in the size range of 2.4±0.7 nm, which were considerably smaller than Ag and Au nanoparticles. The present approach exemplifies a totally green synthesis using the plant derived natural product (gum kondagogu) for the production of noble metal nanoparticles and the process can also be extended to the synthesis of other metal oxide nanoparticles.
已经报道了一种使用胶木（Cochlospermum gossypium）的水溶液合成贵金属纳米粒子的环保方法。在含有胶木的水介质中，完成了胶体 Ag、Au 和 Pt 纳米粒子的合成和稳定。所得的胶体悬浮液在很长一段时间内都非常稳定，不会发生任何氧化。SEM-EDXA、UV-vis 光谱、XRD、FTIR 和 TEM 技术用于表征 Ag、Au 和 Pt 纳米粒子。FTIR 分析表明，胶基质中存在的-OH 基团负责将金属阳离子还原成纳米粒子。UV-vis 研究表明，由于在胶网络中形成了 Au 和 Ag 纳米粒子，分别在 412 和 525nm 处出现明显的表面等离子体共振。XRD 研究表明，纳米粒子具有面心立方结构的晶体性质。本研究中制备的贵金属纳米粒子似乎是均匀的，粒径在 2nm 至 10nm 之间，TEM 分析证明了这一点。形成的 Ag 和 Au 纳米粒子的平均粒径分别为 5.5±2.5nm 和 7.8±2.3nm；而 Pt 纳米粒子的粒径范围为 2.4±0.7nm，明显小于 Ag 和 Au 纳米粒子。本方法采用植物来源的天然产物（胶木）作为生产贵金属纳米粒子的完全绿色合成方法，该方法也可扩展到其他金属氧化物纳米粒子的合成。
