title: Impedimetric Label-Free Immunosensor on Disposable Modified Screen-Printed Electrodes for Ochratoxin A.
abstract: An impedimetric label-free immunosensor on disposable screen-printed carbon electrodes (SPCE) for quantitative determination of Ochratoxin A (OTA) has been developed. After modification of the SPCE surface with gold nanoparticles (AuNPs), the anti-OTA was immobilized on the working electrode through a cysteamine layer. After each coating step, the modified surfaces were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The capacitance was chosen as the best parameter that describes the reproducible change in electrical properties of the electrode surface at different OTA concentrations and it was used to investigate the analytical parameters of the developed immunosensor. Under optimized conditions, the immunosensor showed a linear relationship between 0.3 and 20 ng/mL with a low detection limit of 0.25 ng/mL, making it suitable to control OTA content in many common food products. Lastly, the immunosensor was used to measure OTA in red wine samples and the results were compared with those registered with a competitive ELISA kit. The immunosensor was sensitive to OTA lower than 2 μg/kg, which represents the lower acceptable limit of OTA established by European legislation for common food products.
authors.affiliation: Department of Industrial Engineering, University of Salerno, 84084 Fisciano SA, Italy. fmalvano@unisa.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Malvano
authors.affiliation: Department of Industrial Engineering, University of Salerno, 84084 Fisciano SA, Italy. dalbanese@unisa.it.
authors.forename: Donatella
authors.initials: D
authors.lastname: Albanese
authors.affiliation: Institute for Microelectronics and Microsystems of the National Council of Research (CNR), 80131 Napoli, Italy. alessio.crescitelli@cnr.it.
authors.forename: Alessio
authors.initials: A
authors.lastname: Crescitelli
authors.affiliation: Institute of Atmospheric Pollution Research of the National Council of Research (CNR), 00015 Roma, Italy. roberto.pilloton@cnr.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pilloton
authors.affiliation: Institute for Microelectronics and Microsystems of the National Council of Research (CNR), 80131 Napoli, Italy. emanuela.esposito@cnr.it.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Esposito
mesh_terms: D000906:Antibodies; D015374:Biosensing Techniques; D058266:Dielectric Spectroscopy; D004566:Electrodes; D006046:Gold; D057230:Limit of Detection; D009793:Ochratoxins; D014920:Wine / Q000032:analysis
chemical_list: D000906:Antibodies; D009793:Ochratoxins; C025589:ochratoxin A; D006046:Gold
keywords: Ochratoxin A; electrochemical impedance spectroscopy; immunosensor; screen printed electrodes