Key Laboratory for Bionic Engineering of Ministry of Education, Jilin University, Changchun 130025, People's Republic of China; State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, People's Republic of China.
Key Laboratory for Bionic Engineering of Ministry of Education, Jilin University, Changchun 130025, People's Republic of China.
Anal Chim Acta. 2017 Nov 22;994:65-72. doi: 10.1016/j.aca.2017.10.004. Epub 2017 Oct 17.
Typically, the surface-enhanced Raman scattering (SERS) technique is employed in precious metallic substrates with spontaneously adsorbed probing molecules to acquire signals. Preferred chemical conditions including aggregate status, hydrophilic/hydrophobic surroundings, and smart linkers were created to enable the detection of targets in very low concentrations (lower than 1.0 × 10 M). Although the sensitivity of SERS is applicable to certain areas, it is not satisfied in several cases that require obtaining good resolved signals involving extremely few surface molecules. Thus, further improvements in the sensitivity based on existing SERS techniques pose a challenge and is desirable for all aspects of analytical chemistry. In this study, a novel strategy was employed by constructing a molecular template (MT) on the SERS substrates with spontaneously adsorbed probe molecules to improve the detection sensitivity of probe molecules. The proposed MT-assisted SERS technique differed from previous methods as it provides a completely new method for improving the limit of detection (LOD) of SERS by controlling molecular orientations. The surface selection rules of SERS spectra were first introduced as an effective strategy to improve the detection sensitivity, and this was extremely beneficial with respect to analytical applications. The use of the MT-assisted SERS technique indicated that the LOD of probe molecules of p-aminobenzenethiol (8.0 × 10 M) and 4-mercaptobenzoic (1.0 × 10 M) acids on noble metallic substrates exhibited nearly one order of magnitudes. Hence, the proposed method paves a way to detect the molecules under improved sensitivity at extreme low concentrations. The study corresponded to a proof-of-concept study of MT-assisted SERS for SERS-based applications in ultra-sensitive analysis.
通常情况下，表面增强拉曼散射（SERS）技术是在具有自发吸附探针分子的贵金属衬底上使用的，以获取信号。创建了首选的化学条件，包括聚集状态、亲水/疏水环境和智能连接体，以实现对非常低浓度（低于 1.0×10-7 M）目标的检测。尽管 SERS 的灵敏度适用于某些领域，但在需要获得涉及极少数表面分子的良好分辨信号的情况下，其灵敏度并不满足要求。因此，基于现有 SERS 技术进一步提高灵敏度是一个挑战，也是分析化学各个方面所期望的。在这项研究中，通过在具有自发吸附探针分子的 SERS 衬底上构建分子模板（MT），采用了一种新策略来提高探针分子的检测灵敏度。与之前的方法不同，所提出的 MT 辅助 SERS 技术提供了一种通过控制分子取向来提高 SERS 检测灵敏度的全新方法。首先介绍了 SERS 光谱的表面选择规则作为一种提高检测灵敏度的有效策略，这对于分析应用非常有益。使用 MT 辅助 SERS 技术表明，在贵金属衬底上，对氨基苯硫醇（8.0×10-7 M）和 4-巯基苯甲酸（1.0×10-7 M）探针分子的检测限（LOD）提高了近一个数量级。因此，该方法为在极端低浓度下以提高的灵敏度检测分子铺平了道路。该研究对应于用于超灵敏分析的基于 SERS 的 MT 辅助 SERS 的概念验证研究。
