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.

[1]  L. Solti,et al.  A new monoclonal antibody detecting ochratoxin A at the picogram level , 1996, Letters in applied microbiology.

[2]  C. V. Van Peteghem,et al.  Development of a solid-phase cleanup and portable rapid flow-through enzyme immunoassay for the detection of ochratoxin a in roasted coffee. , 2002, Journal of agricultural and food chemistry.

[3]  A. Wölfling,et al.  Sensitive ELISA Test for Determination of Ochratoxin A , 1996 .

[4]  F. Madrid,et al.  Development of a quantitative and sensitive enzyme-linked immunosorbent assay for ochratoxin a using antibodies from the yolk of the laying hen , 1993 .

[5]  P. Compton,et al.  Steroid radioimmunoassay--effect of shortened incubation time on specificity. , 1981, Clinical chemistry.

[6]  Heidi R. C. Dietrich,et al.  Biosensors and multiple mycotoxin analysis , 2003 .

[7]  G. Palleschi,et al.  Development of an electrochemical ELISA for the screening of 17 beta-estradiol and application to bovine serum. , 2000, The Analyst.

[8]  A. Visconti,et al.  Use of various clean-up procedures for the analysis of ochratoxin A in cereals. , 1998, Journal of chromatography. A.

[9]  R. R. Marquardt,et al.  Quantification of Ochratoxin A in Swine Kidneys by Enzyme-linked Immunosorbent Assay Using a Simplified Sample Preparation Procedure. , 1994, Journal of food protection.

[10]  G. Palleschi,et al.  Electrochemical ELISA for the screening of DDT related compounds: analysis in waste waters , 2003 .

[11]  P. Krogh.  Mycotoxins in food , 1987 .

[12]  Giuseppe Palleschi,et al.  Electrochemical immunosensor for determination of aflatoxin B1 in barley , 2004 .

[13]  J. Miller,et al.  Mycotoxins in grain: compounds other than aflatoxin. , 1994 .

[14]  S. Saeger,et al.  Flow-through membrane-based enzyme immunoassay for rapid detection of ochratoxin A in wheat , 1999 .

[15]  Linda Monaci,et al.  Determination of ochratoxin A in foods: state-of-the-art and analytical challenges , 2004, Analytical and bioanalytical chemistry.

[16]  Giuseppe Palleschi,et al.  Development of an Electrochemical Immunosensor for Ochratoxin A , 2004 .