A benzotriazole-based fluorescent probe with arylboronate recognition for rapid and selective hypochlorite detection in environmental and biological systems.

Abstract

Hypochlorite (ClO-), a biologically and environmentally relevant reactive oxygen species, plays a key role in inflammatory processes and water quality regulation. In this work, a benzotriazole-based fluorescent probe (DTPB) was developed for the sensitive detection of ClO-, employing a pinacol boronate ester as the recognition moiety. Upon reaction with ClO-, the arylboronate group undergoes oxidative hydrolysis to generate the corresponding phenolic product (DTPH-), accompanied by a marked fluorescence quenching at 524 nm. The structural transformation was verified by 1H NMR and high-resolution mass spectrometry (HRMS), while theoretical calculations further elucidated the underlying electronic transition and sensing mechanism. Under physiological conditions (10 mM PBS, pH 7.4), DTPB exhibited excellent photostability, a rapid response within 60 s, a low detection limit of 60 nM, and high selectivity toward ClO- over other reactive species and common ions. The proposed method was successfully applied to the determination of ClO- in various real water samples, showing satisfactory recoveries and low relative standard deviations. In addition, due to its low cytotoxicity and stable optical response, DTPB enabled fluorescence imaging of intracellular ClO- in A549 cells. These results demonstrate that this probe provides a reliable fluorescence-based analytical platform for monitoring hypochlorite in environmental and biological systems, with potential applications in redox-related studies and water safety assessment.