Abstract
A new colorimetric and fluorescence probe NRSH based on Nile-red chromophore for the detection of biothiols has been developed, exhibiting high selectivity towards biothiols over other interfering species. NRSH shows a blue shift in absorption peak upon reacting with biothiols, from 587 nm to 567 nm, which induces an obvious color change from blue to pink and exhibits a 35-fold fluorescence enhancement at 645 nm in red emission range. NRSH displays rapid (<1 min) response for H2S, which is faster than other biothiols (>5 min). The detection limits of probe NRSH towards biothiols are very low (22.05 nM for H2S, 34.04 nM for Cys, 107.28 nM for GSH and 113.65 nM for Hcy). Furthermore, NRSH is low cytotoxic and can be successfully applied as a bioimaging tool for real-time monitoring biothiols in HeLa cells. In addition, fluorescence mechanism of probe NRSH is further understood by theoretical calculations.
Highlights
As important reactive sulfur species, small molecular biothiols, such as hydrogen sulfide (H2 S), cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play important roles in physiological activities and pathological processes [1,2]
The fluorophore NR is selected due to a large long wavelength fluorophore and typical intramolecular charge transfer (ICT) process [47,48,49,50], and DNBS is introduced by esterification reaction to form NRSH, which might feature a weak fluorescence owing to a characteristic photoinduced electron transfer (PET) process
The fluorescent probe NRSH shows to be very effective in detecting biothiols, as expected
Summary
As important reactive sulfur species, small molecular biothiols, such as hydrogen sulfide (H2 S), cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play important roles in physiological activities and pathological processes [1,2]. A variety of fluorescence probes for biothiols have been devised based on various strategies, including deprotection of 2,4-dinitrobenzenesulfonyl (DNBS), cyclization reaction of aldehyde, Michael addition, thiol-halogen nucleophilic substitution, disulfide exchange reaction and others [6,7,8,9]. Among these strategies, the DNBS-based strategy stands out because of the unique sensitivity and high reactivity of DNBS group towards thiolate anion. A new colorimetric and fluorescent probe NRSH (2-O-(2,4-dinitrobenzenesulfonyl)-9-(diethylamino)-5H-benzo[a]phenoxazin-5-one) based on Nile-red fluorophore has been developed to detect the biothiols (Scheme 1).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
