A selective chemoreceptor for Aflatoxin B1.

Aflatoxin B1 (AFB1) is a toxin produced by the mould fungus varieties Aspergillus Flavus and Aspergillus parasiticus, which grows on foodstuffs like peanuts, flour, pepper etc. Due to its high toxicity for the human health, the AFB1 allowed concentration in food and animal feed is limited to ppb according to last EC directives [1]. At present, the methods available for aflatoxin detection are based mainly on HPLC or ELISA techniques. Therefore, new methods with low detection limit and sufficient selectivity towards AFB1 with respect to its less toxic analogous molecules, aflatoxins G1 (AFG1) and G2 (AFG2), need to be developed. Furthermore, portable and simple methods are preferred for the possibility to be used directly on site. In this respect, by using computer modelling, we have identified a chemoreceptor, based on a porphyrin moiety, able to bind selectively AFB1 with respect to AFG1. These predictions were confirmed by evaluating the binding properties of different porphyrin molecules with AFB1, AFG1 and AFG2 in THF. The system was fully characterised by means of UV absorption and steady-state and time resolved fluorescence measurements