Alphatoxin Nanopore Detection of Aflatoxin, Ochratoxin and Fumonisin in Aqueous Solution

Mycotoxins are toxic and carcinogenic metabolites produced by groups of filamentous fungi that colonize food crops. Aflatoxin B (AFB), ochratoxin A (OTA) and fumonisin B (FB) are among the most relevant agricultural mycotoxins, as they can induce various toxic processes in humans and animals. To detect AFB, OTA and FB in the most varied matrices, chromatographic and immunological methods are primarily used; however, these techniques are time-consuming and expensive. In this study, we demonstrate that unitary alphatoxin nanopore can be used to detect and differentiate these mycotoxins in aqueous solution. The presence of AFB, OTA or FB inside the nanopore induces reversible blockage of the ionic current flowing through the nanopore, with distinct characteristics of blockage that are unique to each of the three toxins. The process of discrimination is based on the residual current ratio calculation and analysis of the residence time of each mycotoxin inside the unitary nanopore. Using a single alphatoxin nanopore, the mycotoxins could be detected at the nanomolar level, indicating that alphatoxin nanopore is a promising molecular tool for discriminatory analysis of mycotoxins in aqueous solution.