Highly Selective Ratiometric Fluorescent Probes for Detection of Perborate Based on Excited‐State Intramolecular Proton Transfer (ESIPT) in Environmental Samples and Living Cells

Abstract

AbstractBenzthiazole‐based ratiometric fluorescent probes acetylphenylbenzthiazole (APBT) and acetylnaphthylbenzthiazole (ANBT), were synthesized and characterized. These two excited‐state intramolecular proton transfer (ESIPT)‐based first ratiometric fluorescent probes were shown to be selective and sensitive for perborate (BO3–) among the 15 anions studied in HEPES buffer medium by fluorescence, absorption, and visual emission color change. Upon treatment with perborate in aqueous HEPES buffer solution, the acetyl protective group of probes APBT and ANBT was removed readily and ESIPT of the probes was switched on, which resulted in remarkable photo‐physical changes. Time dependent‐ density functional theory (TD‐DFT) calculations were performed in order to demonstrate the electronic properties of APBT and ANBT and their anion. An easy‐to‐prepare test paper, obtained by dipping the paper into the solution of APBT, was able to detect BO3– in practical samples. Moreover, the utility of the APBT and ANBT probes in perborate recognition has also been demonstrated in Vero cells using Confocal imaging.