利用磁控溅射技术在组装整齐的微球表面依次镀上银、金薄膜, 获得双金属纳米壳层结构。以对巯基苯胺(p-ATP)为探针分子, 研究了该壳层结构在不同激发线下SERS增强差异。测试结果表明, 金银双金属纳米壳层结构在780 nm激光下具有很好的SERS增强效果, 并随着外层金膜厚度的减小而逐渐增强。对各个基底的增强因子进行计算可知, 基底的表面等离子体共振(SPR) 峰与激发线的匹配程度越好, 其增强因子越大。由于金的高稳定性和良好的生物相容性, 该基底在SERS生物传感方面具有很大应用潜力。

Ag and Au films were successively deposited on orderly assembled silica nanospheres to obtain Au-Ag bimetallic nanoshells. P-aminothiophenol (p-ATP) molecules were chosen to detect the surface-enhanced Raman scattering (SERS) performance of the samples using different excitation lasers. The results revealed that the Au-Ag bimetallic nanoshells have excellent SERS activities under excitation light of 780 nm wavelength and the SERS intensity got enhanced as the decreasing of the thickness of Au shell. The calculated enhancement factors (EFs) of p-ATP on the SERS substrates showed that the large EFs appeared when the SPR peaks of SERS substrates well matched excitation lines. The good stability and biocompatibility of Au confirms the Au-Ag bimetallic nanoshells have potential applications in SERS biosensing.