Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing 100029, China; College of Science, Beijing University of Chemical Technology, Beijing 100029, China.
Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing 100029, China.
Biosens Bioelectron. 2015 Feb 15;64:434-41. doi: 10.1016/j.bios.2014.09.053. Epub 2014 Sep 28.
Multifunctional Ag nanoparticle-decorated TiO2 nanorod arrays were prepared by two simple processes. TiO2 nanorod arrays were first fabricated by the hydrothermal route and then Ag nanoparticles were decorated on the nanorods by the chemical reduction impregnation method. Three-dimensional Ag/TiO2 arrays were used as an active substrate for surface-enhanced Raman scattering (SERS). The results show that the detection limit for rhodamine 6G (R6G) was as low as 10(-7)M and the Raman enhancement factor was as large as 10(5). After calibrating the Raman peak intensities of R6G, it could be quantitatively detected. More importantly, the photocatalytic activity of TiO2 provides a self-cleaning capability to the SERS substrate, which can be recycled and used to degrade many Ag surface adsorbates such as R6G, methyl orange, Congo red, and methylene blue after exposure to visible light. The absorbed small molecules can all be rapidly and completely removed from the SERS substrate, which has been successfully reused four times without a decrease in accuracy or sensitivity. Our results reveal that the unique recyclable property not only paves a new way to solve the single-use problem of traditional SERS substrates but also provides more SERS platforms for multiple detections of other organic molecular species.
多功能 Ag 纳米粒子修饰的 TiO2 纳米棒阵列通过两种简单的工艺制备而成。首先通过水热法制备 TiO2 纳米棒阵列，然后通过化学还原浸渍法在纳米棒上修饰 Ag 纳米粒子。三维 Ag/TiO2 阵列被用作表面增强拉曼散射（SERS）的活性基底。结果表明，对罗丹明 6G（R6G）的检测限低至 10(-7)M，拉曼增强因子高达 10(5)。在对 R6G 的拉曼峰强度进行校准后，可以进行定量检测。更重要的是，TiO2 的光催化活性为 SERS 基底提供了自清洁能力，在可见光照射下可以回收并用于降解许多 Ag 表面吸附物，如 R6G、甲基橙、刚果红和亚甲基蓝。吸收的小分子都可以从 SERS 基底上迅速且完全去除，已经成功重复使用了四次，而准确性或灵敏度没有下降。我们的结果表明，这种独特的可回收性不仅为解决传统 SERS 基底的一次性使用问题开辟了新途径，而且为其他有机分子物种的多检测提供了更多的 SERS 平台。
