Porous silicon Fabry-Pérot interferometer designed for sensitive detection of aflatoxin B₁ in field crops

Herein, a label-free sensing platform was designed for accurate, rapid and selective detection of aflatoxin B1 (AFB1), a potent mutagenic and carcinogenic substance in food and feedstuff. Minute AFB1 residues were assessed by competitive immunoassay facilitated on porous silicon Fabry-Pérot interferometer. The immunocomplex formation was biochemically amplified by enzymatic reaction products infiltrating the porous void and alternating the reflectivity spectra in correlation to the AFB1 content. The optical output presented high sensitivity toward target analyte detection in simulated conditions, as low as 0.03 ppb within the dynamic range of 0.01-10 ppb. The selectivity and specificity of the developed sensing platform were cross-validated versus commonly known interfering mycotoxins without compromising its performance values. Finally, the efficiency and the accuracy of the system were demonstrated in three matrices (maize, peanut and wheat) while demonstrating acceptable recovery values of 94-101 %, in compliance with the competitive ELISA standard assay and HPLC.