Zn2+ Binding‐Enabled Excited State Intramolecular Proton Transfer: A Step toward New Near‐Infrared Fluorescent Probes for Imaging Applications

• DOI: 10.1002/adhm.201200025
• Publication Date: 2012-05-11T13:45:35Z
• Authors: Yongqian Xu; Qin Liu; Bairui Dou; Brian Wright; Jingyun Wang; Yi Pang
• Keywords: Stokes shift; Benzoxazole

In order to facilitate the in vivo study of zinc-related biology, it is essential develop a zinc-selective sensor that exhibits both near-infrared (NIR) emission and larger Stokes shift. A fluorescent sensor, Zinhbo-5, has been constructed by using bis(benzoxazole) ligand with 2, 2'-dipicolylamine (DPA) as metal ion receptor. aqueous solution, Zinhbo-5 high sensitivity (K(d) = 2.58 nM(2) ) selectivity for Zn(2+) cation, revealing about 14-fold fluorescence enhancement upon zinc binding give green emission. Remarkably, switches on excited state intramolecular proton transfer (ESIPT), producing desirable region (over 710 nm) large shift (ca. 240 nm). The new probe demonstrated be useful imaging intracellular ion. also detecting distribution during development living zebrafish embryos.