Fluorescence spectroscopy enhancing aflatoxin detection in solid food products: from laboratory setup towards handheld sensing units

Aflatoxins are among the main carcinogens threatening food safety, while imposing severe detection challenges due to their localized presence and undetectability by visual inspection. We present the use of fluorescence spectroscopy for a non-destructive and sensitive detection of aflatoxins, starting from a laboratory research-grade characterization to its integration in a handheld unit. As a case-study, aflatoxin detection in maize and pistachio is considered. The present aflatoxin influences the natural background fluorescence dependent on the matrix of the food products. Both one- and two-photon induced fluorescence are compared, indicating one-photon induced fluorescence as most suited for miniaturization. A compact sensing unit, comprising UV LED excitation (365nm) and fluorescence detection into a single handheld device is presented, showing a promising sensitivity differentiating aflatoxin concentration differences of only 0.6 mu g/kg, while complying to the European regulations, paving the way towards an increased food safety.