Premium
A New Aptameric Biosensor for Cocaine Based on Surface‐Enhanced Raman Scattering Spectroscopy
Author(s) -
Chen Jiwei,
Jiang Jianhui,
Gao Xing,
Liu Guokun,
Shen Guoli,
Yu Ruqin
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200701307
Subject(s) - raman scattering , aptamer , biosensor , raman spectroscopy , substrate (aquarium) , fluorescence , surface enhanced raman spectroscopy , materials science , scattering , chemistry , analytical chemistry (journal) , nanotechnology , optics , chromatography , physics , oceanography , genetics , geology , biology
The present study reports the proof of principle of a reagentless aptameric sensor based on surface‐enhanced Raman scattering (SERS) spectroscopy with “signal‐on” architecture using a model target of cocaine. This new aptameric sensor is based on the conformational change of the surface‐tethered aptamer on a binding target that draws a certain Raman reporter in close proximity to the SERS substrate, thereby increasing the Raman scattering signal due to the local enhancement effect of SERS. To improve the response performance, the sensor is fabricated from a cocaine‐templated mixed self‐assembly of a 3′‐terminal tetramethylrhodamine (TMR)‐labeled DNA aptamer on a silver colloid film by means of an alkanethiol moiety at the 5′ end. This immobilization strategy optimizes the orientation of the aptamer on the surface and facilitates the folding on the binding target. Under optimized assay conditions, one can determine cocaine at a concentration of 1 μ M , which compares favorably with analogous aptameric sensors based on electrochemical and fluorescence techniques. The sensor can be readily regenerated by being washed with a buffer. These results suggest that the SERS‐based transducer might create a new dimension for future development of aptameric sensors for sensitive determination in biochemical and biomedical studies.