Fluorescence Quenching-Based Mechanism for Determination of Hypochlorite by Coumarin-Derived Sensors.

Karolina Starzak,Alicja Matwijczuk,Arkadiusz Matwijczuk,Bernadette Creaven,Sławomir Wybraniec,Dariusz Karcz

doi:10.3390/ijms20020281

Abstract

A fluorescence quenching-based mechanism for the determination of hypochlorite was proposed based on spectroscopic and chromatographic studies on the hypochlorite-sensing potency of three structurally similar and highly fluorescent coumarins. The mode of action was found to rely upon a chlorination of the coumarin-based probes resulting from their reaction with sodium hypochlorite. Importantly, the formation of chlorinated derivatives was accompanied by a linear decrease in the fluorescence intensities of the probes tested. The results obtained suggest the applicability of a coumarin-dependent hypochlorite recognition mechanism for the detection of, as well as for quantitative determination of, hypochlorite species in vitro.

Highlights

The research on coumarin-based sensors is well-established and countless coumarin derivatives have been reported as potential tools for the detection and recognition of various chemical species [1,2,3,4].Regardless of the abundant literature on the subject, a large number of processes governing the modes of action of coumarin-based fluorescent probes remain unclear
7-diethylaminocoumarin-3-carboxylic acid 2, and 7-diethylamino-4-methylcoumarin 3 (Figure 1), selection was primarily dictated by the presence of the 7-diethylamino group, which together with the were chosen as models
The interaction of probes 1–3 with sodium hypochlorite leads to the formation of non-fluorescent chlorinated derivatives, which points indicates that the chlorination reaction is responsible for the linear fluorescence decays of 1–3

Summary

Introduction

The research on coumarin-based sensors is well-established and countless coumarin derivatives have been reported as potential tools for the detection and recognition of various chemical species [1,2,3,4].Regardless of the abundant literature on the subject, a large number of processes governing the modes of action of coumarin-based fluorescent probes remain unclear. Other reports refer to various fluorescence quenching mechanisms as essential for signalling [6,7]. These processes may involve multistep reactions and, in many cases, lead to the formation of diverse products, where identification may prove difficult. The interest of our group in coumarins is primarily due to their significant antimicrobial activities enhanced upon their complexation with selected transition metal salts. Most of the obtained complexes demonstrated high antimicrobial and antifungal activities and numerous aspects of their therapeutic modes of action were studied by our group in detail [15,16,17]

Methods

Results

Conclusion