Carcinogenic and toxic contaminants in food and feed products are nowadays mostly detected by destructive,
time-consuming chemical analyses, like HPLC and LC-MS/MS methods. However, as a consequence of the severe and
growing regulations on food products by the European Union, there arose an increased demand for the ultra-fast,
high-sensitive and non-destructive detection of contaminants in food and feed products. Therefore, we have investigated
fluorescence spectroscopy for the characterization of carcinogenic aflatoxins. With the use of a tunable titanium-sapphire
laser in combination with second and third harmonic wavelength generation, both one- and two-photon induced
fluorescence excitation wavelengths could be generated using the same setup. We characterized and compared the
one- and two-photon induced fluorescence spectra of pure aflatoxin powder, after excitation with 365nm and 730nm
respectively. Moreover, we investigated the absolute fluorescence intensity as function of the excitation power density.
Afterwards, we applied our characterization setup to the detection of aflatoxins in maize grains. The fluorescence spectra
of both healthy and contaminated maize samples were experimentally characterized. In addition to the fluorescence
spectrum of the pure aflatoxin, we observed an unwanted influence of the intrinsic fluorescence of the maize. Depending
on the excitation wavelength, a varying contrast between the fluorescence spectra of the healthy and contaminated
samples was obtained. After a comparison of the measured fluorescence signals, a detection criterion for the optical
identification of the contaminated maize samples could be defined. As a result, this illustrates the use of fluorescence
spectroscopy as a valuable tool for the non-destructive, real-time and high-sensitive detection of aflatoxins in maize.