陈化胶体金的简便合成与光谱特性

Facile synthesis and spectral properties of aged gold colloids

摘要:

文章描述了通过只添加氢氧化钠到氯金酸和十六烷基三甲基溴化铵混合液中合成陈化纳米金胶体，并研究了该胶体的光谱特性。基于傅里叶红外光谱对纳米金的形成机理进行了分析并以紫外可见光谱和扫描电子显微镜表征了添加不同量的氢氧化钠而获得的陈化三个月的胶体金。同时文章获得了吸附于陈化了三个月的胶体金表面上的亚甲基蓝的表面增强拉曼光谱。结果表明，陈化三个月的胶体金其紫外可见光谱具有宽的等离子吸收峰，这种宽化改变在文章对中进行了解释分析。其透射电子显微镜图片表明了在纳米金合成阶段，添加不同量的氢氧化钠可影响纳米金大小，同时不同量的氢氧化钠影响着胶体金的陈化过程并产生出形状依赖的陈化胶体金。表面增强拉曼光谱的增强特性不同证明了所形成的陈化胶体金的大小/形状依赖特征。因此，我们期望着这种陈化胶体金能够在生化分析领域被得到开发应用。

Abstract:

The present article described the spectra properties of aged gold colloids, which were synthesized by only adding NaOH to chloroauric acid and Hexadecyl trimethyl ammonium bromide (CTAB) mixture solution. The formation mechanism for the fabrication of gold nanoparticles (AuNPs) was discussed based on the Fourier transform infrared spectroscopy (FTIR) analysis. The gold colloids with the different amount of NaOH were aged three months and characterized by UV-Vis spectrometer and transmission electron microscopy (TEM). Moreover, surface-enhanced Raman scattering (SERS) spectra of methylene blue (MB) on the aged three months gold colloids were obtained. UV-Vis spectrometer showed the broadening of plasmon absorption peak of aged three months gold colloids. And an explanation for the broadening changes was provided in the as-prepared samples. TEM images demonstrated that the diameter and shape change of the AuNPs depended on adding different of NaOH on the stage of the synthesis, and the NaOH was also affected the aging process. The corresponding SERS spectra on the aged three months gold colloid displayed the size/shape-dependent properties. The aged colloidal gold was expected to exploit and utilize in biochemical analysis field.