Raman and surface‐enhanced Raman spectroscopic studies of the 15‐mer DNA thrombin‐binding aptamer

摘要: Aptamers are single-stranded oligonucleotides that selectively bind to their target molecules owing ability form secondary structures and shapes. The 15-mer (5′-GGTTGGTGTGGTTGG-3′) DNA thrombin-binding aptamer (TBA) binds thrombin following the formation of a quadruplex structure via Hoogsten-type G–G interactions. In present study, Raman SERS spectra TBA thiolated (used facilitate covalent bonding metal nanoparticle) in different conditions investigated. two analogs exhibit vibrations, such as C8N7H2 deformation band at ∼1480 cm−1 guanine tetrad, characteristic presence K+ ions or low temperature. Interestingly, differ markedly from respective normal spectra, possibly due changes conformation upon binding, well specific interaction individual vibrational modes with surface. addition, show significant concentrations, which may be orientation molecule respect This study provides useful information for development label-free aptamer-based sensors assays. Copyright © 2009 John Wiley & Sons, Ltd.