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Monitoring hydrogen sulfide (H2S) in living organisms is very important because H2S acts as a regulator in many physiological and pathological processes. Upregulation of endogenous H2S concentration has been shown to be closely related to the occurrence and development of tumors, atherosclerosis, neurodegenerative diseases and diabetes. Herin, a novel fluorescent probe HND with aggregation-induced emission was designed. Impressively, HND exhibited a high selectivity, fast response (1 min) and low detection limit (0.61 μM) for H2S in PBS buffer (10 mM, pH = 7.42). Moreover, the reaction mechanism between HND and H2S was conducted by Job's plot, HR-MS, and DFT. In particular, HND was successfully employed to detect H2S in HeLa cells. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H 2 S) is a multifunctional gaseous signaling molecule that plays a vital role in several biological processes. In the present study, a BODIPY-based fluorescent probe called 8-[4-((1,4,7,10-tetraazacyclododecane)methyl)phenyl]-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a, 4a-diaza- s -indacene (BA–Cyclen)–Cu was designed and synthesized; this probe is a Cu(Ⅱ) complex that uses Cu(Ⅱ) decomplexation to achieve the sensitive and rapid detection of aqueous H 2 S via the "turn-on" mode. We observed that BA–Cyclen–Cu exhibited good membrane permeability, low toxicity, and lysosome-targeting ability, facilitating H 2 S detection in living cells. Furthermore, we demonstrated the potential biological applications of the probe by measuring exogenous H 2 S originating from Na 2 S and GYY4137, a slow-release donor, and endogenous H 2 S generated via the catalysis of cystathionine- β -synthase in both normal (H9c2) and cancerous (U87) cells. Moreover, BA–Cyclen–Cu was successfully used to detect exogenous H 2 S by the external standard method in fetal bovine serum, the serum of a healthy person, and the serum of a patient with liver cancer. [Display omitted] • BA-Cyclen-Cu displayed high selectivity, sensitivity and fast response toward H 2 S with "turn-on" mode. • BA-Cyclen-Cu have a good performance on exogenous/endogenous H 2 S sensing in cancer cells and normal cells. • BA-Cyclen-Cu was successfully used to detect H 2 S in serum samples. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide and biothiol molecules such as Cys and GSH acted important roles in many physiological processes. To simultaneously detect and distinguish them was quite necessary by a suitable fluorescent probe. A novel chemosensor 4-(4-(benzo[d]thiazol-2-yl)-2-methoxyphenoxy)-7-nitrobenzo[c][1,2,5]oxadiazole (BMNO) was designed to detect H2S/Cys/GSH using the combination of nitrobenzofurazan (NBD) and benzothiazole fluorophores linked by a facile ether bond. The probe BMNO was developed for simultaneous identification of H2S, Cys and GSH. Noticeably, the color changes (from colorless to light purple, light orange and light yellow) of probe BMNO solutions for sensing H2S, Cys and GSH could be observed by naked eyes, respectively. The probe BMNO exhibited high selectivity and sensitivity for H2S, Cys and GSH showing distinct optical signal with detection limit as low as 0.15 μM, 0.03 μM and 0.14 μM, respectively. The sensing mechanism was clarified by spectrum analysis and some controlled experiments. In addition, these outstanding properties of probe BMNO enabled its practical applications in detection H2S in beer, and in cell imaging for Cys and GSH as well. [ABSTRACT FROM AUTHOR]

An endoplasmic reticulum (ER) targetable two-photon fluorescent probe termed ER-N3 is presented for the determination of hydrogen sulfide (H2S) in living cells and mice. The results demonstrate that ER-N3 was highly selective and sensitive to H2S. Confocal fluorescence imaging in living cells indicated that ER-N3 was accumulated in the endoplasmic reticulum and visualized exogenous and endogenous H2S production. Moreover, a burst of H2S upregulated by the nitric oxide donor sodium nitroprusside was monitored. Meanwhile, the increase of H2S ended following the addition of DL-propargylglycine, an inhibitor for cystathionine β-synthase and cystathionine γ-lyase that are the main sources of H2S. Importantly, the exogenous H2S was visualized in abdominal tissue of mice by utilizing two-photon fluorescence microscopy. The ER-N3 fluorescent probe may be an excellent tool to image H2S fluctuations in the endoplasmic reticulum and characterize the relationship between H2S and disease in vivo. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) is a critical gasotransmitter playing an important role in various physiological and pathological processes. The development of fluorescent probes for rapid, sensitive, and selective lysosomal H2S sensing has attracted much attention. Herein we report a rhodamine based probe MF‐N3 that can selectively accumulate in lysosomes and give turn‐on fluorescence in the presence of both H2S and protons. Results show that MF‐N3 has an exclusive response to H2S in the acidic lysosomal environment but does not respond in other organelles or in neutral environments. This strategy can circumvent the fluorescence interference from H2S of other sources, thus providing a high sensitivity and selectivity on lysosomal H2S imaging by fluorescence microscopy. This pH‐dependent lysosome‐targeting fluorescent probe has been successfully applied to lysosomal H2S imaging in living cells and is of great potential for applications to the environmental and biological systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Near-infrared "turn-on" H 2 S fluorescence probe NIR-H 2 S constructed by novel fluorophore dye NIR-OH , excited at 686 nm and emitted at 736 nm. • Easily acquisitive (3 steps synthesis), Naked-eye visible colour change (from purple to green), high selectivity, high sensitivity (0.353 μM H 2 S), satisfactory response and low cytotoxicity. • Successfully imaged exogenous and endogenous H 2 S in living cells. Hydrogen sulfide (H 2 S) plays a substantial role as a messenger in the physiological and pathological processes of many diseases. Recently, the fluorescence probe of H 2 S based on organic dye has attracted great attention. However, the emission of many probes is in the UV–vis region (400–600 nm), so it has the disadvantages of shallow tissue penetration and more vulnerable to spontaneous fluorescence interference. Although several H 2 S probes have been developed that emit more than 650 nm, there is a complex structure difficult to synthesize or unstable in storage. Aimed at simply structural and easily synthesized H 2 S fluorescent probes with emission wavelength more than 650 nm, a novel near-infrared (NIR) probe (NIR-H 2 S) here was rationally designed with 4-(2-carboxyphenyl)-7-(diethylamino)-2-(4-hydroxystyryl)chromenylium (NIR-OH) as a fluorescent dye and 2,4-dinitrophenyl moiety as a recognition group. Addition of H 2 S, the "turn-on" NIR fluorescence response at 736 nm of NIR-H 2 S was displayed, accompanied by a visual colour change from purple to green when excited at 686 nm. As an easily acquisitive H 2 S probe, NIR-H 2 S has been successfully applied to cell imaging for H 2 S detection with the advantages such as long fluorescence emission, low toxicity, high sensitivity and strong selectivity. [ABSTRACT FROM AUTHOR]

A red-emitting (above 600 nm) fluorescent probe based on 3-hydroxyflavone has been developed for the detection of hydrogen sulfide with high sensitivity, good selectivity and a large Stokes shift (162 nm). When the probe was treated with hydrogen sulfide, a remarkable fluorescence enhancement (112-fold) was obtained. Application of this probe was successfully demonstrated by imaging intracellular hydrogen sulfide in living RAW264.7 cells. [ABSTRACT FROM AUTHOR]

A coumarin-based turn on probe, named 3-((E)-3-(1H-indol-3-yl)acryloyl)-2H-chromen-2-one(IAC) was designed and synthesized for the detection of H 2 S in aqueous medium. IAC showed no obvious red fluorescence in Tris-HCl(pH = 7.2, 60% DMF), a 28.2-fold fluorescence enhancement was found when 40 equiv. H 2 S was added. Other analytes such as anions, metal ions and GSH, Cys, Gly did no significant fluorescence enhancement at 580 nm to IAC. The red fluorescence enhancement mechanism between IAC and H 2 S was considered by DFT and ESI-MS. Overall, IAC was successfully applied in cell imaging. A new probe IAC was designed and synthesized for highly specific and sensitive detection of H 2 S with fast response time in living cells. Unlabelled Image • A red emission probe IAC was developed for detection of hydrogen sulfide. • The fluorescent probe IAC reacted with various concentrations of H 2 S and produced gradual color changes from colorless to red under 365 lamp. • The IAC was successfully applied to the qualitative and quantitative detection of H 2 S in real water samples and living cells. • ESI-MS and DFT were further verified that the nucleophilic reaction between IAC and H 2 S. [ABSTRACT FROM AUTHOR]