title: Direct detection of aptamer-thrombin binding via surface-enhanced Raman spectroscopy.
abstract: In this study, we exploit the sensitivity offered by surface-enhanced Raman scattering (SERS) for the direct detection of thrombin using the thrombin-binding aptamer (TBA) as molecular receptor. The technique utilizes immobilized silver nanoparticles that are functionalized with thiolated thrombin-specific binding aptamer, a 15-mer (5'-GGTTGGTGTGGTTGG-3') quadruplex forming oligonucleotide. In addition to the Raman vibrational bands corresponding to the aptamer and blocking agent, new peaks (mainly at 1140, 1540, and 1635 cm(-1)) that are characteristic of the protein are observed upon binding of thrombin. These spectral changes are not observed when the aptamer-nanoparticle assembly is exposed to a nonbinding protein such as bovine serum albumin (BSA). This methodology could be further used for the development of label-free biosensors for direct detection of proteins and other molecules of interest for which aptamers are available.
authors.affiliation: University of California, Davis, Sacramento, California 95817, USA. cvpagba@ucdavis.edu
authors.forename: Cynthia V
authors.initials: CV
authors.lastname: Pagba
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Lane
authors.forename: Hansang
authors.initials: H
authors.lastname: Cho
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wachsmann-Hogiu
mesh_terms: D052157:Aptamers, Nucleotide / Q000097:blood* / Q000737:chemistry* / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods*; D007118:Immunoassay / Q000379:methods; D015336:Molecular Probe Techniques; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013917:Thrombin / Q000032:analysis* / Q000737:chemistry* / Q000276:immunology
chemical_list: D052157:Aptamers, Nucleotide; D013917:Thrombin