Detection of aflatoxin B-1 in barley: Comparative study of immunosensor and HPLC

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 degrees 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.