表面增强拉曼散射活性金纳米粒子修饰有一层银膜。

Surface-enhanced Raman scattering-active gold nanoparticles modified with a monolayer of silver film.

机构信息

Division of Gastroenterology and Hepatology, Department of Internal Medicine, Taipei Medical University Hospital, No. 250, Wu-Hsing St., Taipei 11031, Taiwan.

出版信息

Analyst. 2012 Nov 7;137(21):4943-50. doi: 10.1039/c2an35912j. Epub 2012 Sep 12.

DOI:10.1039/c2an35912j

PMID:22970430

Abstract

As shown in the literature, electrochemical underpotential deposition (UPD) offers the ability to deposit up to a monolayer of one metal onto a more noble metal with a flat surface. In this work, we develop an electrochemical pathway to prepare more surface-enhanced Raman scattering (SERS)-active substrates with Ag UPD-modified Au nanoparticles (NPs) by using sonoelectrochemical deposition-dissolution cycles (SEDDCs). Encouragingly, the SERS of Rhodamine 6G (R6G) adsorbed on these Ag UPD-modified Au NPs exhibits a higher intensity by ca. 12-fold magnitude, as compared with that of R6G adsorbed on unmodified Au NPs. The prepared SERS-active substrate demonstrates a large Raman scattering enhancement for R6G with a detection limit of 2 × 10(-14) M and an enhancement factor of 5.0 × 10(8). Also, the strategy proposed in this work to improve the SERS effects by using UPD Ag based on SEDDCs has an effect on the smaller probe molecules of 2,2'-bipyridine (BPy).

摘要

如文献所示，电化学欠电位沉积（UPD）能够在具有平坦表面的更贵金属上沉积多达单层的一种金属。在这项工作中，我们通过使用声电化学沉积-溶解循环（SEDDC）开发了一种电化学途径，用 Ag UPD 修饰的 Au 纳米粒子（NPs）来制备具有更多表面增强拉曼散射（SERS）活性的基底。令人鼓舞的是，与吸附在未修饰的 Au NPs 上的 R6G 相比，吸附在这些 Ag UPD 修饰的 Au NPs 上的 Rhodamine 6G（R6G）的 SERS 强度约提高了 12 倍。所制备的 SERS 活性基底对 R6G 表现出较大的拉曼散射增强，检测限为 2×10(-14) M，增强因子为 5.0×10(8)。此外，本工作通过 SEDDC 基于 UPD Ag 提出的提高 SERS 效应的策略对 2,2'-联吡啶（BPy）等较小的探针分子也有影响。