Screening iodide anion with selective fluorescent chemosensor

An iodide-sensing, colormetric and selective fluorescent sensor N2,N6-bis(2-(p-nitro-benzamido)ethyl)pyridine-2,6-dicarboxamide, BBPCA, was reported. The recognition properties of BBPCA toward various anions were evaluated in THF/H2O (4/1, v/v) solution by fluorescence emission and UV–vis absorption spectra. The results showed the BBPCA can be used to detect iodide ion based on intermolecular charge transfer (ICT) and heary atom quenching mechanism. The color changes of BBPCA solution from colorless to yellow and a red-shift in the absorption and emission spectra can be observed by adding iodide ions. But it showed no significant changes on the addition of other anions such as F−, Cl−, Br−, HCO3−, NO3−, CO32−.