An Excited-state Intramolecular Proton Transfer-based Ratiometric Fluorescence Probe for Detection of Hypochlorite

A new ratiometric fluorescence probe (HBT-CN) was developed with familiar excited state intramolecular proton transfer (ESIPT) fluorophore 2-(2'-hydroxyphenyl)-benzothiazole (HBT) as framework and diaminomeleonitrile (DMN) group as reactive site. The performance of this probe to monitor HOCl was further investigated. This probe possessed good sensitivity and with the ability to rapidly detect HOCl within seconds with a detection limit as low as 1. 1 x 10(-7) mol/L. Furthermore, this probe displayed high specificity 14 sensing HOCl over other relevant analytes including reactive oxygen species (H2O2, tBuO , ROO center dot) and reactive nitrogen species (NO2-, NO3-, ONOO-, NO center dot) . Importantly , the cell experiments demonstrated that the probe HBT-CN had good cell membrane permeability and could monitor HOCl in live cells by dual-channel.