A Poly Adenine-Mediated Assembly Strategy for Designing Surface-Enhanced Resonance Raman Scattering Substrates in Controllable Manners

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• 作者：Ying Zhu ; Xiangxu Jiang ; Houyu Wang ; Siyi Wang ; Hui Wang ; Bin Sun ; Yuanyuan Su ; Yao He
• 刊名：Analytical Chemistry
• 出版年：2015
• 出版时间：July 7, 2015
• 年：2015
• 卷：87
• 期：13
• 页码：6631-6638
• 全文大小：489K
• ISSN：1520-6882

文摘

In this article, we introduce a Poly adenine (Poly A)-assisted fabrication method for rationally designing surface-enhanced resonance Raman scattering (SERRS) substrates in controllable and reliable manners, enabling construction of core鈥搒atellite SERRS assemblies in both aqueous and solid phase (e.g., symmetric core (Au)-satellite (Au) nanoassemblies (Au鈥揂u NPs), and asymmetric Ag鈥揂u NPs-decorated silicon wafers (Ag鈥揂u NPs@Si)). Of particular significance, assembly density is able to be controlled by varying the length of the Poly A block (e.g., 10, 30, and 50 consecutive adenines at the 5鈥?end of DNA sequence, Poly A10/A30/A50), producing the asymmetric core鈥搒atellite nanoassemblies with adjustable surface density of Au NPs assembly on core NPs surface. Based on quantitative interrogation of the relationship between SERRS performance and assemble density, the Ag鈥揂u NPs@Si featuring the strongest SERRS enhancement factor (EF 鈮?10⁷) and excellent reproducibility can be achieved under optimal conditions. We further employ the resultant Ag鈥揂u NPs@Si as a high-performance SERRS sensing platform for the selective and sensitive detection of mercury ions (Hg²⁺) in a real system, with a low detection limit of 100 fM, which is 鈭? orders of magnitude lower than the United States Environmental Protection Agency (USEPA)-defined limit (10 nM) in drinkable water. These results suggest the Poly A-mediated assembly method as new and powerful tools for designing high-performance SERRS substrates with controllable structures, facilitating improvement of sensitivity, reliability, and reproducibility of SERRS signals.