Effect of wavelength, concentration and modulation on the aflatoxin AFB1 detection by direct absorption spectroscopy in the visible light with a 658 nm diode laser

Aflatoxin (AFB1) is a highly toxic mycotoxin that poses significant health risks through food contamination. Traditional detection methods, such as HPLC and ELISA, provide high sensitivity but are costly, time-consuming, and require complex sample preparation. In this study, this study investigated the capability of laser absorbance spectroscopy (at 858 nm) for AFB1 detection, offering a rapid, cost-effective, and reagent-free alternative. The system was optimized using the Taguchi method to determine the optimal laser wavelength, modulation type, and sample concentration. Calibration curves were constructed for each experimental condition by measuring absorbance as the response. Our results demonstrated high linearity (R2 ≈ 0.99) and an improved detection limit (LOD) of 1.1 µg/L, comparable to conventional methods. This study highlights the potential of laser-based spectroscopy for mycotoxin detection, with future work focusing on validating the technique in real food matrices and integrating it into portable food safety monitoring devices.