Novel Electrochemical Immunosensor for Aflatoxin B1 Detection Utilizing Dual Nanoparticles for Dual-Signal...

A novel electrochemical immunosensor has been proposed for rapid determination of Aflatoxin B₁ (AFB₁). To improve sensitivity, a nanocomposite of AgNPs, ZIF-90, and MWCNTs was integrated for the first time as the electrode modification material, creating a dual-signal amplification strategy. Compared with previously reported sensors that typically employ one or two of these components, this design simultaneously addresses the conductivity limitation of ZIF-90 and the aggregation tendency of MWCNTs, providing a notable advancement in sensitivity. Characterization of the nanocomposite was carried out using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FT-IR). The sensitivity and specificity of the sensor are optimized to achieve reliable trace detection of AFB₁, even at low concentrations relevant to safety standards. Under optimal conditions, the proposed immunosensor achieved a quantitative detection limit of 0.05 ng/mL for AFB₁, which greatly exceeds the sensitivity of traditional methods and can effectively detect within a wide detection range (0.05-1000 ng/mL). In actual sample analysis, the recovery rate ranges from 93.90 to 102.15%, which is consistent with the HPLC results. Therefore, immunosensors may be a promising tool for determining AFB₁.