Two highly sensitive and selective coumarin-based fluorometric probes for the detection of ClO− and cell imaging

Abstract

Two coumarin-based compounds, 2-acetyl-3H-benzo[f]chromen-3-one (BCO) and (1E)-1-(1-(3-oxo-3H-benzo[f]-chromen-2-yl)ethylidene)thiosemicarbazide (BETC), were designed as excellent fluorescent probes for the detection of ClO⁻ in CH₃OH : H₂O (v/v = 1 : 1). The oxidizing reaction between the BCO & BETC probes and ClO⁻ induced an obvious fluorescence enhancement together with a color transformation from colorless to blue. The probes showed preferential selectivity towards ClO⁻ over various anions and metal ions. The detection limits of BCO and BETC were 154 nM and 32 nM, respectively. Interestingly, the tested reactive species, which include ˙OH, ¹O₂, and H₂O₂ do not interfere with the tests of ClO⁻. Furthermore, cell imaging using HepG2 cells revealed that BCO & BETC could be applied as effective fluorescent probes for the detection of ClO⁻ in HepG2 cells.