title: A Poly Adenine-Mediated Assembly Strategy for Designing Surface-Enhanced Resonance Raman Scattering Substrates in Controllable Manners.
abstract: 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-satellite SERRS assemblies in both aqueous and solid phase (e.g., symmetric core (Au)-satellite (Au) nanoassemblies (Au-Au NPs), and asymmetric Ag-Au NPs-decorated silicon wafers (Ag-Au 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' end of DNA sequence, Poly A10/A30/A50), producing the asymmetric core-satellite 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-Au NPs@Si featuring the strongest SERRS enhancement factor (EF ≈ 10(7)) and excellent reproducibility can be achieved under optimal conditions. We further employ the resultant Ag-Au NPs@Si as a high-performance SERRS sensing platform for the selective and sensitive detection of mercury ions (Hg(2+)) in a real system, with a low detection limit of 100 fM, which is ∼5 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.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.forename: Xiangxu
authors.initials: X
authors.lastname: Jiang
authors.forename: Houyu
authors.initials: H
authors.lastname: Wang
authors.forename: Siyi
authors.initials: S
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Sun
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Su
authors.affiliation: ‡Department of Chemistry, Stanford University, Stanford, California 94305, United States.
authors.forename: Yao
authors.initials: Y
authors.lastname: He
mesh_terms: D000225:Adenine / Q000737:chemistry*; D001704:Biopolymers / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D001704:Biopolymers; D000225:Adenine