Probe For H2S Research Articles

Polydimethylsiloxanes - Based Fluorescent Probe for H2S Detection in Living Cells.

The development of fluorescent probes for H2S detection especially in living cells is of great significance due to its fundamental role as signal molecule. A promising scaffold for the development of such probes is polydimethylsiloxanes (PDMS), which is cost-effectiveness, non-toxicity, flexibility, and biocompatibility and easy to post-functionalize. Surprisingly, fluorescent probes for H2S detection based on PDMS have not been investigated. Moreover, 4-nitro - 2,1,3-benzoxadiazole (NBD) derivates provides high fluorescence quantum yield, a large molar absorption coefficient, and sensitivity to environmental changes. Through reasonable design and adjustment of substituents on the NBD group, precise control of its fluorescence properties can be achieved. Herein, a novel H2S fluorescent probe, P-NBD, was designed and synthesized by a one-step aromatic ring nucleophilic substitution of Cl-NBD with a PDMS derivative. Due to the occurrence of the cleavage reaction strategy and the intramolecular charge transfer process, P-NBD can detect H2S via a colorimetric method. The limit of detection is down to 93 nM. P-NBD demonstrated considerable detection capability comparable to other reported types of H2S probes. Moreover, the probe can also be utilized for H2S imaging in HeLa cells. This work provides new insights into the design and synthesis of novel H2S probes while also offering experimental evidence for the application of PDMS in cellular imaging.

A coumarin-based fluorescent probe for imaging H2S and distinguishing breast cancer cells from normal ones

Hydrogen sulfide (H2S) is a crucial endogenous gas signal molecule involved in several physiological functions. Elevation of H2S concentrations is considered a cancer biomarker because it may be connected to the growth of tumors. A thorough comprehension of measuring H2S in living cells and differentiating between malignant and normal cells is crucial. Herein, a multi-responsive probe (C-DNP) was constructed to detect H2S and observe the intramolecular charge transfer “turn-off” sensing mechanism caused by the intervention of the irradiative intramolecular charge transfer between C and DNP. Given that DNP recognizes H2S, a reaction between H2S and the probe-attached DNP could eliminate DNP via ether bond breakage and increased emission. Moreover, 1H NMR titrations, HR-MS, and density-functional theory (DFT) calculations confirmed the proposed sensing mechanism. The probe effectively monitored H2S in different water samples, food samples, paper sensor trips, and living cells. Surprisingly, the probe distinguished tumor-bearing cells from normal cells by expressing the variations in H2S both exogenously and endogenously in normal and breast cancer cells. Therefore, it is anticipated to be an efficient method for monitoring H2S in real samples and biosystems.

An aggregation-induced fluorescence probe for H2S and its application in living cells

Hydrogen sulphide (H2S) plays an important role in the regulation of a number of important physiological and pathological processes. Therefore, the development of new fluorescent probes for H2S is of great importance and has recently attracted much attention. In this paper, a novel coumarin-based fluorescent probe named (1E)-1-(1-(6-chloro-2-oxo-2H-chromen-3-yl)ethylidene)thiosemicarbazide (1), which contained a CN moiety as a specific reaction site for nucleophilic addition of H2S, was prepared. Upon addition of H2S, probe 1 exhibited significant fluorescence enhancement with a detection limit as low as 0.54 μM, accompanied by a colour change from cyan to colourless. The mechanism was confirmed by ESI-MS, Job’s plot, DFT and the probe 1 was successfully applied to the imaging of H2S in HeLa cells.

Headspace separation combined fluorescence detection of hydrogen sulfide with silver-sensitized lanthanide coordination polymer via a simple self-made device

Hydrogen sulfide (H2S), playing unique role on signal transmission in various physiological processes, the rapid and accurate monitoring of it is particularly concerned. The drawbacks of fluorescence probe for H2S, namely poor selectivity or long response time, have always existed. As a test case, here headspace separation combined fluorescence strategy was attempted, on basis of H2S stimuli-responsive AMP/Tb3+/Ag+ or GMP/Tb3+/Ag+ coordination polymer probes. The fluorescence intensity of them is inversely proportional to the concentration of it, due to Ag-S in situ coordination and partial formation of Ag2S. Using the hybrid analysis, a quick response of less than 2.0 min and a high selectivity could be obtained. The signal change (ΔI) of AMP/Tb3+/Ag+ or GMP/Tb3+/Ag+ showed good linearity within the range of 0.5–100 μM and 1.0–150 μM, along with a detection limit (3σ) of 0.2 and 0.4 μM, respectively. When utilized to determine the sulfide level in real samples, it shows recoveries from 96.4 % to 102.3 % with relative standard derivation (RSD) less than 3.0 %. The combination strategy of headspace separation and fluorescence quantitative analysis was verified to effectively eliminate potential interference such as other coexisting non-volatile thiol-containing species, providing a novel avenue to flexibly design the volatile component analysis with high selectivity in complex sample matrixes.

The Application of Hydrogen Sulfide Fluorescent Probe in Food Preservation, Detection and Evaluation.

This work primarily reviewed the response mechanism of fluorescent probes for H2S detection in foodstuffs in recent years, as well as the methodologies employed for detecting foodstuffs. Firstly, the significance of studying H2S gas as an important signaling molecule is introduced. Subsequently, a review of the response mechanism of the scientific community on how to detect H2S in foodstuffs samples by fluorescent probe technology is carried out. Secondly, the methods commonly used for detecting foodstuffs samples are discussed, including the test strip method and the spiking recovery methods. Nevertheless, despite the significant advancements in this field, there remain some research gaps. Finally, the article identifies the remaining issues that require further attention in current research and proposes avenues for future investigation. More importantly, this work identifies the current limitations of research in this field and proposes future applications of fluorescent probes for H2S in assessing food freshness and determining food spoilage. Therefore, this review will provide robust technical support for the protection of consumer health and the advancement of the sustainable development of the food industry and also put forward some new ideas and suggestions for future research.

Analysis of optical properties and response mechanism of H2S fluorescent probe based on rhodamine derivatives

H2S plays a crucial role in numerous physiological and pathological processes. In this project, a new fluorescent probe, SG-H2S, for the detection of H2S, was developed by introducing the recognition group 2,4-dinitrophenyl ether. The combination of rhodamine derivatives can produce both colorimetric reactions and fluorescence reactions. Compared with the current H2S probes, the main advantages of SG-H2S are its wide pH range (5–9), fast response (30 min), and high selectivity in competitive species (including biological mercaptan). The probe SG-H2S has low cytotoxicity and has been successfully applied to imaging in MCF-7 cells, HeLa cells, and BALB/c nude mice. We hope that SG-H2S will provide a vital method for the field of biology.

An easily accessible probe for H2S based on AIE mechanism and its application in cell imaging

Hydrogen sulfide (H2S) is a crucial endogenous gas transmitter, maintaining the redox homeostasis in biological systems. Thus, a real-time and specific H2S detection approach is urgently necessary to study the attack and management of disorders linked to H2S. In this paper, a novel fluorescent probe HMP based on AIE property for the detection of H2S was elaborately conducted. In PBS buffer solution HMP exhibited high photostability, low detection limit (0.82 μM), significant anti-interference ability and fast response time and specificity to H2S. What’s more, it could be employed for the monitoring and luminescent imaging of H2S with Hela cells, thereby broadening the prospective capacity for diagnosing associated diseases.

An Aggregation-Induced Fluorescence Probe for Detection H2S and Its Application in Cell Imaging.

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.

A Red-Emission Fluorescent Probe for Intracellular Biothiols and Hydrogen Sulfide Imaging in Living Cells.

This research centers on the development and synthesis of a longwave fluorescence probe, labeled as 60T, designed for the simultaneous detection of hydrogen sulfide, cysteine/homocysteine, and glutathione. The probe showcases a swift response, good linearity range, and heightened sensitivity, boasting that the detection limits of the probe for Cys, Hcy, GSH and H2S were 0.140, 0.202, 0.259 and 0.396 μM, respectively. Notably, its efficacy in monitoring thiol status changes in live MCF-7 cells is underscored by a substantial decrease in fluorescence intensity upon exposure to the thiol trapping reagent, N-ethyl maleimide (NEM). With an impressive red emission signal at 630 nm and a substantial Stokes shift of 80 nm, this probe exhibits remarkable sensitivity and selectivity for biothiols and H2S, indicating promising applications in the diagnosis and surgical navigation of relevant cancers.

Activity-Based Fluorescent Probes for Hydrogen Sulfide and Related Reactive Sulfur Species.

Hydrogen sulfide (H2S) is not only a well-established toxic gas but also an important small molecule bioregulator in all kingdoms of life. In contemporary biology, H2S is often classified as a "gasotransmitter," meaning that it is an endogenously produced membrane permeable gas that carries out essential cellular processes. Fluorescent probes for H2S and related reactive sulfur species (RSS) detection provide an important cornerstone for investigating the multifaceted roles of these important small molecules in complex biological systems. A now common approach to develop such tools is to develop "activity-based probes" that couple a specific H2S-mediated chemical reaction to a fluorescent output. This Review covers the different types of such probes and also highlights the chemical mechanisms by which each probe type is activated by specific RSS. Common examples include reduction of oxidized nitrogen motifs, disulfide exchange, electrophilic reactions, metal precipitation, and metal coordination. In addition, we also outline complementary activity-based probes for imaging reductant-labile and sulfane sulfur species, including persulfides and polysulfides. For probes highlighted in this Review, we focus on small molecule systems with demonstrated compatibility in cellular systems or related applications. Building from breadth of reported activity-based strategies and application, we also highlight key unmet challenges and future opportunities for advancing activity-based probes for H2S and related RSS.

Transformational Modulation of Fluorescence to Room Temperature Phosphorescence in Metal-Organic Frameworks with Flexible C-S-C Bonds.

Photoluminescent metal-organic frameworks (MOFs) have been a subject of considerable interest for many years. However, the regulation of excited states of MOFs at the single crystal level remains restricted due to a lack of control methods. The singlet-triplet emissive property can be significantly influenced by crystal conformational distortions. This review introduces an intelligent responsive MOF material, denoted as LIFM-SHL-3a, characterized by flexible C-S-C bonds. LIFM-SHL-3a integrates elastic structural dynamics with fluorescence and room temperature phosphorescence (RTP) modulation under heating conditions. The deformable carbon-sulfur bond essentially propels the distortion of molecular conformation and alters the stacking mode, as illustrated by single-crystal-to-single-crystal transformation detection. The deformation of flexible C-S-C bonds leads to different noncovalent interactions in the crystal system, thereby achieving modulation of the fluorescence (F) and RTP bands. In the final state structure, the ratio of fluorescence is 66.7%, and the ratio of RTP is 32.6%. This stands as a successful demonstration of modulating F/RTP within the dynamic MOF, unlocking potential applications in optical sensing and beyond. Especially, a PL thermometer with a relative sensitivity of 0.096-0.104%·K-1 in the range of 300-380 K and a H2S probe with a remarkably low LOD of 125.80 nM can be obtained using this responsive MOF material of LIFM-SHL-3a.

Glycosidase-activated H2S donorsto enhance chemotherapy efficacy

Hydrogen sulfide (H2S) plays a critical role in cancer biology. Herein, we developed a series of glycosidase-triggered hydrogen sulfide (H2S) donors by connecting sugar moieties (including glucose, galactose and mannose) to COS donors via a self-immolative spacer. In the presence of corresponding glycosidases, H2S was gradually released from these donors in PBS buffer with releasing efficiencies from 36 to 67 %. H2S release was also detected by H2S probe WSP-1 after treatment HepG2 cells with Man1. Cytotoxicities of these glycosylated H2S donors were evaluated against HepG2 by MTT assay. Among them, Man1 and Man2 exhibited an obvious reduction of cell viability in HepG2 cells, with cell viability as 37.6 % for 80 μM of Man. Consistently, significant apoptosis was observed in HepG2 cells after treatment with Man1 and Man2. Finally, We evaluated the potential of Man1 for combination therapy with doxorubicin. A synergistic effect was observed between Man1 and Doxorubicin in HepG2 and Hela cells. All these results indicated glycosidase-activated H2S donorshave promising potential for cancer therapy.

A dual-color ESIPT-based probe for simultaneous detection of hydrogen sulfide and hydrazine.

Hydrogen sulfide (H2S) and hydrazine (N2H4) are toxic compounds in environmental and living systems, and hydrogen sulfide is also an important signaling molecule. However, in the absence of dual-color probes capable of detecting both H2S and N2H4, the ability to monitor the crosstalk of these substances is restricted. Herein, we developed an ESIPT-based dual-response fluorescent probe (BDM-DNP) for H2S and N2H4 detection via dually responsive sites. The BDM-DNP possessed absorbing strength in the detection of H2S and N2H4, with a large Stokes shift (156 nm for H2S and 108 nm for N2H4), high selectivity and sensitivity, and good biocompatibility. Furthermore, BDM-DNP can be utilized for the detection of hydrogen sulfide and hydrazine in actual soil, and gaseous H2S and N2H4 in environmental systems. Notably, BDM-DNP can detect H2S and N2H4 in living cells for disease diagnosis and treatment evaluation.

A human serum albumin-binding-based fluorescent probe for monitoring hydrogen sulfide and bioimaging.

In this work, a fluorescent probe, TPABF-HS, was developed for detecting hydrogen sulfide (H2S) using a human serum albumin (HSA)-binding-based approach for amplifying the fluorescence signal and extending the linear correlation range. Compared to the most recent probes for H2S, the most interesting feature of the detection system developed herein was the especially wide linear range (0-1000 μM (0-100 eq.)), which covered the physiological and pathological levels of H2S. TPABF-HS could be used in applications high sensitivity and selectivity with an LOD value of 0.42 μM. Further, site-competition experiments and molecular docking simulation experiments indicated that signal amplification was realized by the binding of the TPABF fluorophore to the naproxen-binding site of HSA. Moreover, the extension of the measurement span could allow for applications in living cells and Caenorhabditis elegans for imaging both exogenous and endogenous H2S. This work brings new information to the strategy of signal processing by exploiting fluorescent probes.

Sunlight-powered total green synthesis of silver nanoresonators from aqueous extract of soybean (Glycine max) chunks: A highly specific colorimetric probe for H2S

We report herein a total green synthesis of silver nano resonators having 43.77 nM concentration with their most frequent average size of ∼ 17 nm. The reaction mixture comprising of aqueous extract of soybean (Glycine max) chunks (15 mL) and AgNO3 (1 mL, 0.1 M) in a 100 mL round bottom flask was irradiated with sunlight for 3 hrs to bring out this synthesis. The as prepared AgNPs were fully characterized through various spectroscopic (FTIR & UV–Vis) and microscopic (SEM, TEM, SAED, EDX, AFM and DLS) studies. The same AgNPs were further exploited for highly selective detection and determination of a janus faced analyte like H2S from its aqueous solution at submicromolar level (LOD 7.39×10-7 M). The H2S is known for its role as one of the gaso-neurotransmitters in humans beside playing dubious role towards our environment. Two spiked real samples of water from pond and sewage were subjected for determination of their H2S content against these AgNPs, showed recoveries of 99 % and 106 % respectively.

A novel coumarin-fluorescein-based fluorescent probe for ultrafast and visual detection of H2S in a Parkinson’s disease model

Hydrogen sulfide (H2S) has a crucial impact on diverse biological processes and has been shown to be related to various diseases. Many probes have been developed to detect intracellular H2S by fluorescent imaging. However, the development of rapid, highly selective and sensitive H2S probes remains a challenge. Herein, two fluorogenic probes, CNS and FCS, are designed and synthesized for the ultrafast detection of H2S with fluorescein and coumarin fluorophores. The results show that both probes can be applied to monitor and image endogenous H2S in cervical cancer HeLa cells and live zebrafish, and FCS shows a higher sensitivity, selectivity and fluorescence intensity. We then further applied FCS in a Parkinson's disease Drosophila model, and the results show that FCS can precisely indicate the level of H2S in the Parkinson's disease model. Thus, FCS will likely to be applied for the early diagnosis of Parkinson’s disease.

Specific imaging of intracellular hydrogen sulfide by a positively charged NIR fluorescent probe

The poor water solubility of traditional activatable organic molecular probes usually limits their detection ability in physiological environment. In this work, a positively charged H2S probe was designed, which exhibited a significantly enhanced responsiveness to H2S in the aggregated state due to the increased positive charge density on the aggregate surface. Under physiological conditions, the probe could be activated by H2S with specificity and sensitivity to release near-infrared fluorescence signal. Moreover, endogenous H2S levels in living cells were successfully monitored by using this probe. We expect that this probe can provide a new strategy for the design of activatable probes to break the limitation of poor water solubility of conventional organic molecular probes.

Advances and Opportunities in H2S Measurement in Chemical Biology.

Hydrogen sulfide (H2S) is an important biological mediator across all kingdoms of life and plays intertwined roles in various disciplines, ranging from geochemical cycles to industrial processes. A common need across these broad disciplines is the ability to detect and measure H2S in complex sample environments. This Perspective focuses on key advances and opportunities for H2S detection and quantification that are relevant to chemical biology. Specifically, we focus on methods for H2S detection and quantification most commonly used in biological samples, including activity-based H2S probes, the methylene blue assay, the monobromobimane assay, and H2S-sensitive electrode measurements. Our goal is to help simplify what at first may seem to be an overwhelming array of detection and measurement choices, to articulate the strengths and limitations of individual techniques, and to highlight key unmet needs and opportunities in the field.

Multiple Applications of a Novel Fluorescence Probe with Large Stokes Shift and Sensitivity for Rapid H2S Detection.

Herein, a novel fluorescence probe Fla-DNP based on flavonol has been designed and synthesized for rapid, specific detection of H2S. With the addition of H2S, Fla-DNP triggered thiolysis and released Fla displaying the "turn-on" fluorescence response at 566nm, which is consistent with the reaction site predicted by calculating Electrostatic potential and ADCH charges. As an easily available H2S probe, Fla-DNP has the advantages of high selectivity, anti-interference, low detection limit (0.834μM), short response time (6min), and large Stokes shift (124nm). The sensing mechanism of H2S was determined by HRMS analysis and DFT calculation. Moreover, Fla-DNP processes a wide range of multiple applications, including the detection of H2S in environmental water samples with good recovery rates ranging from 89.6% to 102.0%, as well as tracking the production of H2S during food spoilage. Meanwhile, the probe exhibits superior biocompatibility and can not only be available used for H2S detection in living cells but be further designed as an H2S-activated CO photoreleaser, based on which it can be developed as a targeted anti-cancer drug.

A lipid droplet-targeting fluorescent probe for specific H2S imaging in biosamples and development of smartphone platform

Hydrogen sulfide (H2S), a significant gas signal molecule, is closely related to various physiological/pathological processes. The monitoring of H2S is crucial in understanding the occurrence and development of diseases such as cancers. Emerging evidence suggests that abnormal regulation of Lipid droplets (LDs) is associated with many human diseases. For example, cancer cells are characterized by the abnormal accumulation of LDs. Therefore, understanding the relationship between LDs and cancer is of great significance for developing therapies against cancer. To address this challenge, we designed and developed a LD-targeting and H2S-activated probe (BTDA-DNB) by engineering a 2,4-dinitrophenyl ether (DNBE) as the H2S reactive site. In the presence of H2S, a strongly fluorescent emitter, 3-(benzo[d]thiazol-2-yl)-N,N-diethyl-2-imino-2H-chromen-7-amine (BTDA) was obtained with the leaving of DNBE group. BTDA-DNB displayed favorable sensitivity, selectivity and functioning well at physiological pH. The probe features excellent LD-targeting specificity and low cellular toxicity. The practical applications of LD-targeting probe BTDA-DNB as H2S probe in living cells, cancer tissues and Arabidopsis seedling have been evaluated. The excellent imaging performance demonstrates a potential ability for cancer diagnosis. Benefitted from the excellent performance on visual recognition H2S, a robust smartphone-integrated platform for H2S analysis was also successfully established.