Monoclonal antibody based electrochemical immunosensor for the determination of ochratoxin A in wheat.
Competitive electrochemical enzyme-linked immunosorbent assays based on disposable screen-printed electrodes have been developed for quantitative determination of ochratoxin A (OTA). The assays were carried out using monoclonal antibodies in the direct and indirect format. OTA working range, I(50) and detection limits were 0.05-2.5 and 0.1-7.5mugL(-1), 0.35 (+/-0.04) mugL(-1) and 0.9 (+/-0.1) mugL(-1), 60 and 100mugL(-1) in the direct and indirect assay format, respectively. The immunosensor in the direct format was selected for the determination of OTA in wheat. Samples were extracted with aqueous acetonitrile and the extract analyzed directly by the assay without clean-up. The I(50) in real samples was 0.2mugL(-1) corresponding to 1.6mug/kg in the wheat sample with a detection limit of 0.4mug/kg (calculated as blank signal -3sigma). Within- and between-assay variability were less than 5 and 10%, respectively. A good correlation (r=0.9992) was found by comparative analysis of naturally contaminated wheat samples using this assay and an HPLC/immunoaffinity clean-up method based on the AOAC Official Method 2000.03 for the determination of OTA in barley.
Alarcón
Sergio Hugo
SH
Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma Tor Vergata, Via Della Ricerca Scientifica 1, 00133 Roma, Italy; Departamento de Química Analítica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina.
Palleschi
Giuseppe
G
Compagnone
Dario
D
Pascale
Michelangelo
M
Visconti
Angelo
A
Barna-Vetró
Ildikó
I