Detection of Aflatoxin B₁ in Barley: Comparative Study of Immunosensor and HPLC

Abstract

In the present work, an indirect competitive electrochemical enzyme linked immunosorbent assay (ELISA) has been used for determination of aflatoxin B₁ (AFB₁) in barley. The method involves the use of disposable screen‐printed carbon electrodes (SPCEs) and anti‐aflatoxin B₁ monoclonal antibodies (MAb) for immunosensor development.

The specificity of the assay was assessed by studying the cross‐reactivity of the MAb relative to AFB₁. The results indicated that the MAb could readily distinguish AFB₁ from other toxins, with the exception of AFG₁.

The stability of the coating reagents was evaluated using SPCEs coated with AFB₁‐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 AFB₁ 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 AFB₁ in barley.

Keywords:

• Aflatoxin B₁
• electrochemical immunosensor
• ELISA
• HPLC
• barley

The authors wish to thank the Italian project ‘Aflarid’ for financial support. Also N.H.S. Ammida thanks Garyounis University, Benghazi, Libya for providing financial support to pursue postgraduate studies in Tor‐Vergata University, Rome, Italy.