writer：Yaru Jia, Lei Zhang, Liping Song, Liwei Dai, Youju Huang, Jiawei Zhang, Zhiyong Guo*, Tao Chen*
keywords：Au giant vesicle, Au nanowire, anisotropic growth, seed-mediated growth
source：期刊
specific source：Langmuir, 2017, DOI: 10.1021/acs.langmuir.7b03261
Issue time：2017年
Sensitivity and reproducibility are two major concerns to improve the performance and extend the range of practical applications of Surface Enhanced Raman Scattering (SERS). Theoretical report reveals that hot spots formed by gold nanoparticles with tip-to-tip configuration would generate the maximum electric field enhancement because of lightning rod effect. In our present study, we constructed an Au giant vesicle consisting of anchored tiny gold nanowires to provide the high density of sharp tip-to-tip nanogaps for SERS application. The tiny gold nanowires were directly grown and anchored onto the surfaces of PS (polystyrene) microspheres by seed-mediated method. Then the removing of PS microspheres by THF (tetrahydrofuran) led to the formation of the Au giant vesicles with hierarchical cage structures, providing the sharp tips and high density of hot spots for improving SERS performance. Compared with non-wires (island and nanoparticle) vesicles, Au giant vesicles with tiny wires showed higher SERS enhancement factor (9.57×107) and quantitative SERS analysis in the range of 10-4 to 10-7 M. In addition, the large scale Au giant vesicle array on the silica substrate resulted in the high reproducibility of SERS signals with the variation of intensities less than 7.6%.