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Impedimetric DNA Aptasensor for Sensitive Detection of Ochratoxin A in Food
Author(s) -
Castillo Gabriela,
Lamberti Ilaria,
Mosiello Lucia,
Hianik Tibor
Publication year - 2012
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201100485
Subject(s) - aptamer , ochratoxin a , detection limit , dielectric spectroscopy , biosensor , chemistry , electrode , dna , electrochemistry , analytical chemistry (journal) , materials science , nanotechnology , chromatography , mycotoxin , biochemistry , food science , biology , genetics
We report a high sensitive biosensor based on DNA aptamers for detection of ochratoxin A (OTA). The thiolated DNA aptamers specific to OTA of different configurations have been immobilized by chemisorption to the surface of a gold electrode. Electrochemical impedance spectroscopy (EIS) in the presence of a redox probe [Fe(CN) 6 ] −3/−4 has been used for the determination of the charge transfer resistance, R ct , followed by addition of OTA. The R ct increased with increasing OTA concentration in the range of 0.1–100 nM. The limit of detection (0.12–0.40 nM) depended on the configuration of the aptamers. The sensor was regenerable and validated in food samples with satisfactory recovery.