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This article describes the conjugation between aflatoxin B1 (AFB1), one of the major mycotoxins, and alkaline phosphatase (AP), one of the most used enzymes for immunoassays. In addition, an application of the ELISA method for aflatoxin B1 determination in corn is presented. Three AFB1-AP conjugates in different toxin-enzyme ratios were prepared and tested. The ELISA results, developed with the most effective conjugate obtained, showed a satisfactory working range between 2.4 and 4000 ng of toxin/g of corn. The detection limit was 2 ng/g in corn samples, and recoveries ranged from 105 to 120%. [ABSTRACT FROM AUTHOR]

In this work are presented methods for detection of aflatoxin B1 and type-A trichothecenes, based on the use of indirect competitive ELISA format coupled with a 96-well screen-printed microplate. Electrochemical immunoassays for AFB1, T-2, and HT-2 were performed and the activity of the alkaline phosphatase or horseradish peroxidase labeled enzymes were measured using intermittent pulse amperometry (IPA) as electrochemical technique. Using standard solutions of the target analyte the LOD of the assays were 0.3 and 0.2 ng ml-1 for T-2 and AFB1 respectively, while the sensitivity was 1.2 ng ml-1 for both. For Aflatoxin B1, a stability study of electrochemical plate was also performed. Moreover, the matrix effect was evaluated using two different extraction treatments from corn. [ABSTRACT FROM AUTHOR]

In the present work, an indirect competitive electrochemical enzyme linked immunosorbent assay (ELISA) has been used for determination of aflatoxin B 1 (AFB 1 ) in barley. The method involves the use of disposable screen‐printed carbon electrodes (SPCEs) and anti‐aflatoxin B 1 monoclonal antibodies (MAb) for immunosensor development. The specificity of the assay was assessed by studying the cross‐reactivity of the MAb relative to AFB 1 . The results indicated that the MAb could readily distinguish AFB 1 from other toxins, with the exception of AFG 1 . The stability of the coating reagents was evaluated using SPCEs coated with AFB 1 ‐bovine serum albumin (BSA) conjugate. The results showed that the coated electrodes could be used for up to one month after their preparation and storage at 4°C. Prior to evaluating the performance of the electrochemical immunosensor for AFB 1 with spiked samples, the effect of barley extract on assay performance was tested. Using this calibration method, the limit of detection (LOD) was found to be 90 pg mL -1 . The linear range was 0.1–10 ng mL -1 , and recoveries ranged from 100%–125%. The results obtained were confirmed by high performance liquid chromatography (HPLC) coupled with fluorescence detection. These results demonstrated the suitability of the proposed method for routine screening of AFB 1 in barley. [ABSTRACT FROM AUTHOR]