Article ID Journal Published Year Pages File Type
869734 Biosensors and Bioelectronics 2009 5 Pages PDF
Abstract

A novel label-free electrochemical impedimetric immunosensor for sensitive detection of ochratoxin A (OTA) was reported. A two-step reaction protocol was elaborated to modify the gold electrode. The electrode was first derivatized by electrochemical reduction of in situ generated 4-carboxyphenyl diazonium salt (4-CPDS) in acidic aqueous solution yielded stable 4-carboxyphenyl (4-CP) monolayer. The ochratoxin A antibody was then immobilized making use of the carbodiimide chemistry. The steps of the immunosensor elaboration and the immunochemical reaction between ochratoxin A and the surface-bound antibody were interrogated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The impedance change, due to the specific immuno-interaction at the immunosensor surface was utilized to detect ochratoxin A. The increase in electron-transfer resistance (ΔRet) values was linearly proportional to the concentration of OTA in the range of 1–20 ng mL−1, with a detection limit of 0.5 ng mL−1.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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