An NBD-based colorimetric and fluorescent chemosensor for Zn2+ and its use for detection of intracellular zinc ions

A new 7-nitrobenz-2-oxa-1,3-diazole (NBD) based colorimetric and fluorescence chemosensor for Zn2+, an ion involved in many biological processes, was designed and synthesized. The NBD-probe 1 displays a red-to-yellow color change and an enhancement of fluorescent intensity in the presence of an aqueous solution of Zn2+ ions (pH 7.2). Internal charge transfer (ICT) and photoinduced electron transfer (PET) mechanisms are responsible for these changes. The practical use of this probe was demonstrated by its application to the biologically relevant detection of Zn2+ ions in pancreatic β-cells.