Aptamer-based surface-enhanced Raman scattering (SERS) sensor for thrombin based on supramolecular recognition, oriented assembly, and local field coupling
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- 作者：Liyuan Yang ; Cuicui Fu ; Hailong Wang ; Shuping Xu…
- 关键词：Thrombin ; SERS ; Local field coupling ; Oriented assembly
- 刊名：Analytical and Bioanalytical Chemistry
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：409
- 期：1
- 页码：235-242
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Analytical Chemistry; Biochemistry, general; Laboratory Medicine; Characterization and Evaluation of Materials; Food Science; Monitoring/Environmental Analysis;
- 出版者：Springer Berlin Heidelberg
- ISSN：1618-2650
- 卷排序：409
文摘
A supramolecular recognition and oriented assembly system was developed on chip for the highly selective surface-enhanced Raman scattering (SERS) detection of thrombin by means of the aptamer-based SERS tag method. A 15-base thrombin-binding aptamer (TBA15) with a thiol end was first immobilized on an Ag nanoprism array by the S–Ag bond. This aptamer has high binding affinity with thrombin when it folds into a G-quadruplex structure. After the recognition between the aptamer and thrombin, a bridge is built between the SERS tag (4-mercaptobenzoic acid marked Ag nanoparticle) and the fixed thrombin based on the activation of the carboxylic group of 4-mercaptobenzoic acid. Thus, the quantitative detection of thrombin can be achieved based on the SERS intensity of the immobilized SERS tags. The obvious advantages of this sensing method are as follows: (1) remarkable SERS enhancement due to the high electric field coupling effect via the gap structure formation, which improves the sensitivity of the SERS detection and the limit of detection of this method arrives in 1.6 × 10–11 M, (2) high selectivity based on the specific aptamer recognition toward thrombin, which can be extended to other enzymes easily by changing a proper sequence, (3) high repeatability of SERS signals according to a highly ordered structure, and (4) highly efficient oriented assembly of a sandwich structure over an Ag nanoprism array. The proposed method is expected to be a practical implement in medical diagnosis.