Dicyanoisophorone-based near-infrared fluorescent probe with large Stokes shift for the monitoring and bioimaging of hypochlorite

Abstract

Hypochlorite (ClO−), as one of reactive oxygen species (ROS), is closely linked to various illnesses and is essential for the proper functioning of immune system. Hence, monitoring and assessing ClO− levels in organisms are extremely important for the clinical diagnosis of ClO−-related disorders. In this study, a novel ClO−-selective fluorescent probe, DCP-ClO, was synthesized with dicyanoisophorone-xanthene unit as parent fluorophore, which displayed excellent selectivity towards ClO−, near-infrared emission (755 nm), large Stokes shift (100 nm), real-time response to ClO−, high sensitivity (LOD = 3.95 × 10−8 M), and low cytotoxicity. The recognition mechanism of DCP-ClO towards ClO− was confirmed to be a typical ICT process by HPLC-MS, HR-MS, 1H NMR and theoretical calculations. Meanwhile, DCP-ClO demonstrated remarkable efficacy in monitoring ClO− levels in water samples and eye-catching ability in imaging endogenous/exogenous ClO− in living organisms, which verified its potential as a powerful tool for the recognition of ClO− in complex biological systems.