A coumarin-based fluorescent probe for differential identification of sulfide and sulfite in CTAB micelle solution

Abstract

Sulfite and sulfide share several similarities in terms of chemical properties, such as nucleophilic and reducing reactivities. Therefore, they may disturb the detection of each other. In order to discriminate between these two kinds of sulfur-containing species, a new probe -N3 was developed, in which para-azidobenzenyl ketone was covalently incorporated to a coumarin fluorophore linked by a C=C double bond. Sulfite and sulfide can respectively react with the C=C double bond and the azido group to give different products, consequently, they can be differentially identified by UV-vis and fluorescence spectroscopy as well as by the naked eye. Selectivity and competition results reveal that -N3 is a good candidate for the detection of sulfide and sulfite. The bioimaging experiment demonstrates the potential of the -N3 probe for the differential imaging of sulfide and sulfite in living cells.

An effective colorimetric and ratiometric fluorescent probe for bisulfite in aqueous solution

“…However, the reactive group always responded to other nucleophilic anions immediately, such as thiols, CN À and H 2 S [39e42,68]. In our case, the a,b-unsaturated ketone was not interfered with other anions, but the response time always needed 60 min [46,47]. Therefore, we need to search further for rapid and sensitive bisulfite probes.…”

“…So far, only one ratiometric fluorescent imaging of probe with a,b-unsaturated ketone group in the presence of 1 mM CTAB has been reported by Tian et al [47]. However, the fluorescent imaging was not performed in living cells because of CTAB's definite cellular toxicity.…”

“…1B). The proposed sensing mechanism involves Michael addition between bisulfite and the a,b-unsaturated ketone [46,47]. The nucleophilic addition of HSO 3 À to the electrophilic C]C double bond shortens the p-conjugation of probe BICO (Scheme 1).…”

“…Three reported probes with large emission wavelengths (l em > 640 nm) use dual excited wavelengths and respond to bisulfite and sulfite [45,48,49]. Two bisulfite probes with a,b-unsaturated ketone group exhibit good properties in practical samples, but they lack living cell imaging [46,47]. Therefore, probes with high sensitivity for cell imaging are needed.…”

A fast‐responsive fluorescent probe for sulfite and its bioimaging

“…As an alternative, the fluorescence method has received much attention due its the advantages of convenience, high sensitivity, fast response and ease of live-cell imaging (14)(15)(16). Fluorescent probes for SO 3 2-have been mainly based on the addition to an aldehyde moiety or a nucleophilic addition (17)(18)(19)(20)(21)(22)(23)(24)(25), and levulinate cleavage mediated by SO 3 2- (26)(27)(28)(29)(30)(31)(32)(33)(34)(35). However, these probes suffer from low selectivity in the presence of biothiols such as cysteine, homocysteine, glutathione and a relatively long reaction time, which are not suitable for detecting or imaging SO 3 2-in living cells.…”