【摘要】 以NaBH4为还原剂,采用化学还原法制备了纳米金溶胶,发现以pH=7的金前驱液还原得到的纳米金粒子具有最强的紫外吸收(525 nm),当以聚乙烯吡咯烷酮(PVP)为稳定剂时,此吸收紫移到510 nm.TEM观察金粒子大小为5～8 nm.PVP、聚乙烯醇(PVA)和吐温-80等能较好地稳定纳米金粒子,而十二烷基苯磺酸钠、PEG-1000和OP乳化剂等则没有稳定作用.以紫外-可见光谱(UV-Vis)、X光荧光光谱(XRF)、透射电子显微镜(TEM)等研究了纳米金粒子与R-藻红蛋白的相互作用,发现R-藻红蛋白本身对纳米金粒子具有良好的稳定作用.当R-藻红蛋白与纳米金粒子共存时,R-藻红蛋白所具有的538 nm吸收带强度有所增强,并发生紫移,同时578 nm的荧光强度也明显减弱,这表明R-藻红蛋白与纳米金粒子的相互作用对R-藻红蛋白的空间结构产生了影响,导致位于R-藻红蛋白外缘藻红素发色团(PEB)的微环境发生了改变.凝胶柱层析及分光光度分析结果进一步证实了金纳米粒子与藻红蛋白存在明显的相互作用,这种相互作用可能与藻红蛋白分子中所包含的氨基基团有关.更多还原

【Abstract】 Gold precursor solutions with pH values of 1,5,7,and 9 were prepared and the solutions were reduced to obtain colloid gold nanoparticles using NaBH4 solution as reducing agent in presence of stabilizer.It is found that PVP,PVA,and Tween80 other than sodium dodecylbenzenesulfonate,PEG-1000,and OP emulsion are good stabilizers.When the colloid gold without any stabilizer has the maximum absorption at 525 nm,the absorption PVP-stabilized gold nanoparticles is shifted to 510 nm and the size of gold particles is about 58 nm.The interaction of gold nanoparticles with R-phycoerythrin was first investigated by UV-Vis absorption spectroscopy,X-ray fluorescence spectroscopy and transmission electron microscopy.It is found that the triple peak type of R-phycoerythrin at 498,538 and 566 nm was observed.The average diameter of gold nanoparticles was about 10 nm and highly dispersed and stable in R-phycoerythrin solution.The intensity and position of the absorption spectrum at 538 nm was changed at the presence of gold nanoparticles and its intensive fluorescence emissions at 578 nm were decreased.It is suggested that the interaction between R-phycoerythrin and gold nanoparticles has an effect on the strcuture of R-phycoerythrin and can change the micro-environment of red-colored phycoerythrobilin chromophores in R-phycoerythrin.The results from gel-column chromatography and spectrophotometer analysis of R-phycoerythrin-gold colloid solution indicate that the interaction is also present,probably being resulted from amino groups included in R-phycoerythrin molecule.更多还原