Exploration of a New Solvatochromic Dye Bearing the Excited-State Intramolecular Proton Transfer Functionality

Abstract

In an effort to explore a multifunctional dye, we investigated the spectroscopic properties of a benzofuran-based fluorophore, ( E )-3-(6-(diethylamino) benzofuran-2-yl)-1-(2-hydroxyphenyl)prop-2-en-1-one (DABP). We found that DABP shows a strong solvatrochromic effect in aprotic solvents and the excited-state intramolecular proton transfer (ESIPT) in protic solvents. We measured the fluorescence lifetime of DABP in different solvents and discovered that its lifetime decreases dramatically because of strong hydrogen bonding. One remarkable feature of the DABP emission is its high sensitivity to water content. We utilized this property to detect amyloid oligomers and observed that DABP is highly sensitive toward early-stage amyloid aggregates. © 2016 Korean Chemical Society, Seoul & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.