Autori: Lucian-Gabriel Zamfir, Irina Geana, Sondes Bourigua, Lucian Rotariu, Camelia Bala,Abdelhamid Errachid, Nicole Jaffrezic-Renault
Editorial: Sensors and Actuators B: Chemical, 159, p.178-184, 2011.
A label-free immunosensor for the detection of ochratoxin A (OTA) based on use of magnetic nanoparticles(MNPs was developed. A gold electrode was modified using bovine serum albumin conjugate with a glutaraldehyde thiolamine linker, creating a layer that prevents non-specific binding of OTA on gold. The OTA antibodies were attached to MNPs using the carbodiimide chemistry and afterwards were immobilized on the modified gold electrode using a strong magnetic field. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and surface plasmon resonance (SPR) were used to characterize each step in immunosensor development. The impedance variation due to the specific antibody-OTA interaction was correlated with the OTA concentration in the samples. The increase in electron-transfer resistance values was proportional to the concentration of OTA on a linear range between 0.01 and 5 ng/mL, with a detection limit of 0.01 ng/mL. SPR measurements showed a larger response range (1-50 ng/mL) with a detection limit of 0.94 ng/mL. Analytical results were in accordance with standard ELISA test kit.
Cuvinte cheie: Ochratoxin A, Magnetic nanoparticles, Impedimetric, SPR