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A Sensitive, Label‐Free, Aptamer‐Based Biosensor Using a Gold Nanoparticle‐Initiated Chemiluminescence System
Author(s) -
Qi Yingying,
Li Baoxin
Publication year - 2011
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.201001856
Subject(s) - aptamer , chemiluminescence , luminol , biosensor , colloidal gold , detection limit , chemistry , combinatorial chemistry , covalent bond , nanoparticle , thrombin , nanotechnology , chromatography , materials science , biochemistry , organic chemistry , microbiology and biotechnology , platelet , immunology , biology
Abstract We report a label‐free, aptamer‐based chemiluminescent biosensor. The biosensor relies upon the catalytic activity of unmodified gold nanoparticles (AuNPs) on the luminol–H 2 O 2 chemiluminescence (CL) reaction, and the interaction of unmodified AuNPs with the aptamer. The unmodified AuNPs can effectively differentiate unstructured and folded aptamer. The binding of the aptamer with the target can induce the AuNP aggregation in the presence of 0.5 M NaCl, and after aggregation the catalytic activity of the AuNPs on the luminol–H 2 O 2 CL reaction is greatly enhanced. During the assay, no covalent functionalization of the AuNPs or aptamer is required. The detection limit of thrombin was estimated to be as low as 26 f M , and the sensitivity was more than 4 orders of magnitude better than that of known AuNP‐based colorimetric methods for the detection of thrombin. This aptamer‐based biosensor offers the advantages of being simple, cheap, rapid, and sensitive