Ren Haiting, Sun Yan, Wang Junjie, Qiu Hongxing, Zhang Shenghao, Zhang Yueshou, Yu Xingxing, Hu Jieyu, Hu Yongjun
MOE Key Laboratory of Laser Life Science, Guangdong Provincial Key Laboratory of Laser Life Science, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
Anal Methods. 2023 Aug 24;15(33):4094-4103. doi: 10.1039/d3ay00661a.
In recent research, anisotropic plasmonic core-shell nanomaterials have gained a lot of attention in surface-enhanced Raman scattering (SERS) due to their brilliant uniformity and optical properties. Herein, a bimetallic core-molecule-shell (CMS) composite nanorod SERS substrate nanomaterial (Au NB-DT@Ag NRs) was designed and synthesized under precise regulation. The inner core is gold nanobipyramids (Au NBs), which possess superior plasmonic properties. Uniform Au NBs of five different sizes were fabricated a penta-twinned gold seed mediated growth method. The length varied from 160 to 62 nm and the corresponding diameter varied from 60 to 23 nm while the longitudinal surface plasmonic resonance (SPR) changed from 908 to 715 nm. The SERS activity of five Au NBs were compared and the optimally sized one with a length of 78 nm and width of 28 nm was set as the inner core. After modification with the Raman reporter (DT), different amounts of silver were deposited on the surface of Au NB-DTs to form an Au NB-DT@Ag nanocomposite. The shape of the nanostructure gradually became a rod and lengthened while the longitudinal SPR wavelength varied from 733 nm to 664 nm with an increase in the amount of silver nitrate added. The Au NB-DT@Ag NRs with the best SERS activity (b-3) could realize the quantitative detection of the toxic dyes malachite green (MG) and crystal violet (CV) of concentrations as low as 5 × 10 M, showing good reproducibility and stability. This work offers a new design strategy for a SERS substrate for reliable quantitative SERS detection applications.
在最近的研究中，各向异性等离子体核壳纳米材料因其出色的均匀性和光学特性，在表面增强拉曼散射（SERS）领域备受关注。在此，设计并精确调控合成了一种双金属核-分子-壳（CMS）复合纳米棒SERS基底纳米材料（Au NB-DT@Ag NRs）。内核是具有优异等离子体特性的金纳米双锥（Au NBs）。通过五重孪晶金种子介导生长法制备了五种不同尺寸的均匀Au NBs。其长度从160 nm变化到62 nm，相应直径从60 nm变化到23 nm，同时纵向表面等离子体共振（SPR）从908 nm变化到715 nm。比较了五种Au NBs的SERS活性，将长度为78 nm、宽度为28 nm的最佳尺寸的Au NBs作为内核。在用拉曼报告分子（DT）修饰后，不同量的银沉积在Au NB-DTs表面，形成Au NB-DT@Ag纳米复合材料。随着添加硝酸银量的增加，纳米结构的形状逐渐变为棒状并变长，纵向SPR波长从733 nm变化到664 nm。具有最佳SERS活性的Au NB-DT@Ag NRs（b-3）能够实现对低至5×10⁻⁸ M浓度的有毒染料孔雀石绿（MG）和结晶紫（CV）的定量检测，具有良好的重现性和稳定性。这项工作为可靠的定量SERS检测应用提供了一种新型SERS基底的设计策略。
