Abstract
In this study, we exploit the sensitivity offered by surfaceenhanced 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.
Original language | English (US) |
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Article number | 047006 |
Journal | Journal of Biomedical Optics |
Volume | 15 |
Issue number | 4 |
DOIs | |
State | Published - Jul 2010 |
Keywords
- Aptamer
- Direct detection
- Label-free assay
- Quadruplex
- Surface-enhanced raman scattering
- Thrombin
ASJC Scopus subject areas
- Biomedical Engineering
- Biomaterials
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics