Potassium-Ion-Selective Fluorescent Sensors To Detect Cereulide, the Emetic Toxin of , in Food Samples and HeLa Cells.

We report the development of new chemical probes for cereulide, a toxic metabolite produced by specific strains of , through displacement of potassium cations from a preformed specific complex and a subsequent change in the fluorescence emission. For this purpose, we designed fluorescent probes for potassium cations that were suitable for displacement assays with cereulide from organic extracts. The fluorescence detection of natural cereulide in rice samples was achieved by using synthetic cereulide as a reference and a potassium fluorescent reporter, and this was found to be useful as a portable and fast method for the in situ detection of cereulide in food extracts.