Detection Of Hydrogen Sulfide Research Articles

Simple turn-on fluorescent probe for ultrafast and highly selective detection of hydrogen sulfide in aqueous solutions

5H-Benzimidazo[1,2-c]quinazoline-6-thione (BI–QT), was synthesized as a benzimidazole-based probe to detect H2S. BI–QT exhibits a fluorescent “turn-on” response in DMSO/H2O (9:1, HEPES 10 mM, pH 7.4) upon the addition of H2S. The BI–QT probe can determine micromolar (0–600 µM) H2S concentrations in aqueous systems, with a detection limit of 1.12 µM. Interestingly, BI–QT exhibited an ultrafast response to H2S, with maximum intensity achieved almost instantly when exposed to H2S. BI–QT is largely unaffected by pH and responds reliably over the wide 4–11 pH range, which highlights its applicability to various physiological scenarios. UV–vis, fluorescence, and 1H NMR spectroscopic analyses investigated the sensing mechanism. The practicality of the probe was demonstrated using water samples and living cells.

Construction of an effective near-infrared fluorescence “turn-on” probe for hydrogen sulfide detection and imaging in living inflammatory cell and zebrafish models

Hydrogen sulfide (H2S) can act as a gaseous signaling mediator closely associated with inflammation development. In this work, we designed a fluorescence turn-on near-infrared (NIR) fluorescent probe CIT-H2S based on Intermolecular Charge Transfer (ICT) for the detection of H2S in living inflammatory cells and zebrafish. On this basis, a dicyanoisophorone fluorophore was chosen as the fluorescence signal reporting group of CIT-H2S, and an azide group was constructed as the recognition group of H2S. CIT-H2S is characterized by high selectivity and sensitivity for H2S over other interference species. The fluorescence intensity at 661 nm showed good linearity in the range of H2S concentration from 0 to 10 μM, with an excellent limit of detection (LOD) as low as 81.52 nM. Impressively, CIT-H2S has been visualized for detecting H2S in drug-induced inflammatory cell and zebrafish models, thus indicating that CIT-H2S is a robust tool with the ability to study the occurrence and development of hydrogen sulfide and inflammation.

Design and characterization of a Near-Infrared Fluorescent Probe SCN for selective detection of Hydrogen Sulfide (H2S) in living systems and food samples

Hydrogen sulfide (H₂S) is a colorless compound with a characteristic rotten egg odor that serves as a significant indicator of pathological processes and food spoilage. In this study, we developed a novel probe SCN for H2S detection. When exposed to H2S, the Probe SCN selectively cleaves the oxygen-nitrile bond, resulting in a strong red fluorescence emission at 662 nm, which can be attributed to recovery from the intramolecular charge transfer (ICT) effect. This probe demonstrated outstanding features, including a substantial Stokes shift (236 nm) and a low detection limit of 0.41 μM. We successfully used the Probe SCN to detect H2S changes in common food samples such as eggs, fish, pork, and shrimp. Furthermore, the Probe SCN can also be used to detect H2S in living cells and mice. These findings confirmed the effectiveness of the SCN probe as a real-time tool for H2S detection and related imaging applications.

A near-infrared turn-on fluorescent probe for the detection of hydrogen sulfide in water samples and food spoilage

Hydrogen sulfide (H2S) is a poisonous pollutant that endangers the environment, and H2S is also produced during food spoilage. Herein, we constructed a dicyanoisophorone-based near-infrared (NIR) fluorescent probe (DCID) to detect H2S. DCID exhibited significant turn-on fluorescence at 700 nm with a low limit of detection (LOD = 74 nM), large Stokes shift (220 nm), prominent selectivity, and response time (100 s) toward H2S. Importantly, the DCID probe had powerful applications in the detection of H2S in environmental samples and food spoilage. In addition, based on DCID-loaded test strips and combined a smartphone sensing platform, which provided a portable and convenient approach for the detection of H2S.

Responsive β-Diketonate-europium(III) Complex-Based Probe for Time-Gated Luminescence Detection and Imaging of Hydrogen Sulfide In Vitro and In Vivo.

As a crucial biological gasotransmitter, hydrogen sulfide (H2S) plays important roles in many pathological and physiological processes. Highly selective and sensitive detection of H2S is significant for the precise diagnosis and evaluation of diverse diseases. Nevertheless, challenges remain in view of the interference of autofluorescence in organisms and the stronger reactivity of H2S itself. Herein, we report the design and synthesis of a novel H2S-responsive β-diketonate-europium(III) complex-based probe, [Eu(DNB-Npketo)3(terpy)], for background-free time-gated luminescence (TGL) detection and imaging of H2S in autofluorescence-rich biological samples. The probe, consisting of a 2,4-dinitrobenzenesulfonyl (DNB) group coupled to a β-diketonate-europium(III) complex, shows almost no luminescence owing to the existence of intramolecular photoinduced electron transfer. The cleavage of the DNB group by a H2S-triggered reaction results in the recovery of the long-lived luminescence of the Eu3+ complex, allowing the detection of H2S in complicated biological samples to be performed in TGL mode. The probe showed a fast response, high specificity, and high sensitivity toward H2S, which enabled it to be successfully used for the quantitative TGL detection of H2S in tissue homogenates of mouse organs. Additionally, the low cytotoxicity of the probe allowed it to be further used for the TGL imaging of H2S in living cells and mice under different stimuli. All of the results suggested the potential of the probe for the investigation and diagnosis of H2S-related diseases.

Developing an ESIPT-based ratiometric fluorescent probe with fast-response for cellular imaging of hydrogen sulfide

Hydrogen sulfide (H2S) plays a crucial role in various physiological processes and is implicated in the pathogenesis of several diseases. The fluorescent probe (E)-2-(3-(3-(benzo[d]thiazol-2-yl)-2-hydroxy-5-methylstyryl)-5,5-dimethylcyclohex-2-en-1-ylidene) malononitrile (BTCMN) has been designed to image H2S in living cells using the excited-state intramolecular proton transfer (ESIPT) mechanism. This probe is developed by coupling 2-(2′-hydroxyphenyl) benzothiazole (HBT) with dicyanoisophorone through a H2S-responsive CC bond. Upon interaction with H2S, BTCMN exhibits a remarkable fluorescent change from red to green. BTCMN, which has shown exceptional performance in detecting hydrogen sulfide (H2S) with super-fast response times, large Stokes shifts (252 nm), specific selection towards H2S, and low detection limits. Importantly, BTCMN has been successfully used for visualizing endogenous and exogenous H2S in HepG2 cells with low cytotoxicity. These features collectively contribute to its effectiveness as a fluorescent probe for detecting H2S in living cells.

Enhanced H2S gas sensing utilizing UV-assisted In2O3@ZnO nanosheets

In the realm of environmental protection, there is a growing demand for efficient and environmentally friendly gas sensors. In this study, we employed a simple hydrothermal method to synthesize nanosheets composed of zinc oxide (ZnO)-doped indium oxide (In2O3), utilizing zeolitic imidazolate framework-8 (ZIF-8) as a precursor. These nanosheets demonstrated exceptional sensitivity and selectivity in detecting hydrogen sulfide (H2S) gas. A comprehensive analysis of crystal structure, chemical states, elemental composition, surface area, and morphology was conducted. Brunauer–Emmett–Teller (BET) surface area measurements to assess the materials' textural properties revealed that the nanosheets labeled In2O3/0.1ZnO possessed a high specific surface area of 49.02 m2/g, greater than the 45.65 m2/g of pure In2O3 nanosheets, a crucial factor contributing to the observed exceptional sensitivity and selectivity in detecting H2S gas. Particularly noteworthy is the substantial improvement in gas detection response from 109.9 to 146.2 (approximately 24.7 %) observed in the In2O3/0.1ZnO material under UV irradiation at the optimal temperature of 250 °C. This enhancement emphasizes the material's potential for superior gas detection. The incorporation of ZIF-8-derived ZnO nanostructures played a crucial role in creating additional active sites, further enhancing the gas-sensing capabilities. Importantly, this innovative synthesis technique ensures the production of clean, non-toxic materials, aligning with environmental conservation objectives, and holds promise for achieving heightened sensitivity and selectivity in the detection of environmentally harmful gases.

Near-infrared fluorescent probe based on the regulatory dye pKa for imaging of H2S in rice roots and living cells

Hydrogen sulfide (H2S) is a key factor in various biological processes such as plant grow and its response to environmental stress. Here, we develop a novel near-infrared (NIR) fluorescent probe for detecting hydrogen sulfide based on the regulatory NIR dye pKa values. After triggering the H2S substitution response, probe A with introducing the cyano moiety not only exhibits a significant near-infrared emission (Emax: 724 nm) response in physiological environments, but also shows a fast response, high selectivity, and sensitivity (LOD as 0.52 µM). In addition, probe A with low biological cytotoxicity is successfully used for imaging detection of cellular exogenous and endogenous hydrogen sulfide. More importantly, in situ imaging of probe A tracks the H2S fluctuations in the rice root system and its response to environmental stress. Hence, this work offers a new NIR fluorescence imaging monitoring tool for hydrogen sulfide in biological systems.

Dual-Mode Ce-MOF Nanozymes for Rapid and Selective Detection of Hydrogen Sulfide in Aquatic Products.

Increasing concern over the safety of consumable products, particularly aquatic products, due to freshness issues, has become a pressing issue. Therefore, ensuring the quality and safety of aquatic products is paramount. To address this, a dual-mode colorimetric-fluorescence sensor utilizing Ce-MOF as a mimic peroxidase to detect H2S was developed. Ce-MOF was prepared by a conventional solvothermal synthesis method. Ce-MOF catalyzed the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by hydrogen peroxide (H2O2) to produce blue oxidized TMB (oxTMB). When dissolved, hydrogen sulfide (H2S) was present in the solution, and it inhibited the catalytic effect of Ce-MOF and caused the color of the solution to fade from blue to colorless. This change provided an intuitive indication for the detection of H2S. Through steady-state dynamic analysis, the working mechanism of this sensor was elucidated. The sensor exhibited pronounced color changes from blue to colorless, accompanied by a shift in fluorescence from none to light blue. Additionally, UV-vis absorption demonstrated a linear correlation with the H2S concentration, ranging from 200 to 2300 µM, with high sensitivity (limit of detection, LOD = 0.262 μM). Fluorescence intensity also showed a linear correlation, ranging from 16 to 320 µM, with high selectivity and sensitivity (LOD = 0.156 μM). These results underscore the sensor's effectiveness in detecting H2S. Furthermore, the sensor enhanced the accuracy of H2S detection and fulfilled the requirements for assessing food freshness and safety.

Enhanced oxygen anions generation on Bi2S3/Sb2S3 heterostructure by visible light for trace H2S detection at room temperature

Bismuth sulfide (Bi2S3) possesses unique properties that make it a promising material for effective hydrogen sulfide (H2S) detection at room temperature. However, when exposed to light, the oxygen anions (O2–(ads)) adsorbed on the surface of Bi2S3 can react with photoinduced holes, ultimately reducing the ability to respond to H2S. In this study, Bi2S3/Sb2S3 heterostructures were synthesized, producing photoinduced oxygen anions (O2–(hv)) under visible light conditions, resulting in enhanced H2S sensing capability. The Bi2S3/Sb2S3 heterostructure sensor exhibits a two-fold increase in sensing response to 500 ppb H2S under in door light conditions relative to its performance in darkness. Additionally, the sensing response of the Bi2S3/Sb2S3 sensor (Ra/Rg= 23.3) was approximately five times higher than pure Bi2S3. The improved sensing performance of the Bi2S3/Sb2S3 heterostructures is attributable to the synergistic influence of the heterostructure configuration and light modulation, which enhances the H2S sensing performance by facilitating rapid charge transfer and increasing active sites (O2–(hv)) when exposed to visible light.

A highly selective fluorescent sensor with aggregation-induced emission for detection of H2S and its application in live cells imaging

Hydrogen sulfide (H2S) is traditionally considered as an ecologically toxic gas, has been proven to be the third endogenous signalling gasotransmitter and plays important roles in physiological and pathophysiological conditions. Herein, we designed and synthesized a novel “turn off” fluorescent probe for the detection of hydrogen sulfide(H2S) in vitro. Probe A could detect H2S in CH3CN/PBS system with significant fluorescence quenching. Probe A also showed obviously aggregation-induced emission (AIE) effects. Fluorescence titration experiments revealed probe A combine with H2S in a 1: 1 ratio with a detection limit of 6.54 μM. Cell imaging results demonstrated the potential applicability of probe A for H2S detection in living cells. The supramolecular assembly of probe A and β-cyclodextrin further revealed the interaction with H2S.

A water-soluble fluorescent sensor accelerated with ortho-aldehyde for the detection of hydrogen sulfide in spoiled food and cells

In view of the important physiological and pathological roles of hydrogen sulfide (H2S) in living systems, the development of a highly sensitive and selective fluorescent sensor for the detection of H2S is crucial. A novel fluorescent sensor has been synthesized in this paper, which utilises thiolysis of thiophene esters assisted by an ortho-aldehyde group as a sensing strategy to achieve highly specific detection of H2S. It was shown that the sensor has excellent sensing performance for H2S with 300-fold fluorescence enhancement, Stokes shift up to 170 nm, fast response time up to 5 min, high sensitivity (limit of detection, LOD = 55 nM) and good selectivity. The sensor has been successfully used for colourimetric and fluorescence detection of H2S in solution. Test papers prepared with the sensor can be used to detect H2S gas in spoiled eggs and milk. In addition, the sensor can image H2S in living cells and zebrafish.

A cytoplasm-applicative aggregation-induced fluorescent probe for detecting hydrogen sulfide and imaging study

Herein, a cytoplasm-applicative aggregation-induced fluorescent probe Pyr-HS was developed for detecting H2S in living cells and C. elegans. The trials were carried out to utilize the aggregation-induced strategy to realize the wide linear range as well as cytoplasm-applicative imaging capability. In-solution tests suggested that Pyr-HS responded to H2S with notable fluorescence enhancement and naked-eye observed color change. The detecting product Pyr-OH exhibited the obvious aggregation to form crystal clusters. By coupling the correlation curves, the linear range of the detecting system was extended to 0–1500 μM, with the LOD value of 0.4481 μM. The Pyr-HS has high sensitivity and selectivity. With low cyto-toxicity, Pyr-HS achieved the imaging of both the exogenous and endogenous H2S in living cells and Caenorhabditis elegans. The aggregation of the detecting product locked the fluorescence signals in the cytoplasm, which was a potential cytoplasm-applicative imaging pattern. This work was informatic with the aggregation-induced strategy in introducing the wide linear range and cytoplasm-applicative imaging.

Rapidly responsive and highly selective NIR fluorescent probe for detecting hydrogen sulfide in food samples and living cells

Hydrogen sulfide (H2S) is a pungent gas that is one of the key mediators of signal transduction in biological systems, and its presence is related to the freshness of some protein foods. Using phenothiazine derivatives as fluorophores and 2, 4-dinitrobenzene sulfonate (DNBS) fragments as reaction groups, a near-infrared (NIR) probe WX-HS for H2S identification was designed. With the addition of H2S, WX-HS appeared a strong fluorescence signal at 660 nm with short reaction time (90 s) and high sensitivity, and fluorescence state change from non-fluorescent to orange-red. In addition, WX-HS could effectively detect H2S produced during food oxidation. Based on its low cytotoxicity, the WX-HS probe further enabled the detection and imaging of H2S in A549 cells.

Micro-spherical SnO2/Zn2SnO4 heterojunction for sensitive and selective detection of hydrogen sulfide

Detecting hydrogen sulfide (H2S) with high performance is crucial in various applications, particularly in breath diagnostics. Ternary metal oxide materials with appropriate structures are seen as promising for precise and sensitive gas detection. In this study, a composite material of Zn2SnO4/SnO2 with different crystal shapes was created using a one-step co-precipitation method by adjusting the precursor ratio. Among these, the micro-spherical Zn2SnO4/SnO2 composite displayed the smallest size, largest specific surface area, and highest pore volume. Gas sensors utilizing this material exhibited effective response and recovery to H2S concentrations ranging from 0.2 to 25 ppm. Notably, a response value of 1850 was achieved for 1 ppm H2S at a relatively low operating temperature of 160℃. Additionally, the sensor demonstrated exceptional selectivity (selectivity coefficient ≥185), repeatability, and long-term stability. This type of gas sensor holds significant potential for applications in breath analysis and disease diagnosis.

Smartphone Imaging Device for Multimodal Detection of Hydrogen Sulfide Using Cu-Doped MOF Sensors.

Multimodal sensing platforms may offer reliable, fast results, but it is still challenging to incorporate biosensors with high discriminating ability in complex biological samples. Herein, we established a highly sensitive dual colorimetric/electrochemical monitoring approach for the detection of hydrogen sulfide (H2S) utilizing Cu-doped In-based metal-organic frameworks (Cu/In-MOFs) combined with a versatile color selector software-based smartphone imaging device. H2S can result in the enhancement of the electrochemical signal because of the electroactive substance copper sulfide (CuxS), the decrease of the colorimetric signal of the characteristic absorption response caused by the strong coordination effect on Cu/In-MOFs, and the obvious changes of red-green-blue (RGB) values of images acquired via an intelligent smartphone. Attractively, the Cu/In-MOFs-based multimodal detection guarantees precise and sensitive detection of H2S with triple-signal detection limits of 0.096 μM (electrochemical signals), 0.098 μM (colorimetric signals), and 0.099 μM (smartphone signals) and an outstanding linear response. This analytical toolkit provides an idea for fabricating a robust, sensitive, tolerant matrix and reliable sensing platform for rapidly monitoring H2S in clinical disease diagnosis and visual supervision.

One-Step Synthesis of Chitosan Hydrogel as Electrochemical Chemosensor for Hydrogen Sulfide Detection in Pregnancy-Induced Hypertension Syndrome Serum Sample.

Oxidative stress caused by pregnancy-induced hypertension syndrome significantly affects the health of pregnant women. Hydrogen sulfide is a typical gaseous signal molecule against oxidative stress, and it is of profound significance to develop a detection method. In this study, a stimuli-responsive hydrogel was constructed based on the coordination and bonding principle of metal ions and chitosan (CS) to realize the quantitative detection of hydrogen sulfide (H2S). The chain of CS contains a large number of amino groups and hydroxyl groups, which can form the coordination structure with Cu2+, triggering CS to form a stable hydrogel. The hydrogel can be formed within about 5 s, which has the characteristics of rapid preparation. In the presence of target H2S, the cross-linking agent Cu2+ in the hydrogel can compete out, resulting in the collapse of the hydrogel and the release of the electrochemical probe. By detecting the concentration of the released electrochemical probe, the quantitative detection of H2S can be achieved. The prepared hydrogel has a good linear relationship with the concentration of H2S from 1 μM to 60 μm. At the same time, the hydrogel has good specificity and stability, and it can be applied to the detection of H2S in serum samples.

Tailoring the Ni-O Microenvironment in Amorphous-Dominated Highly Active and Stable Zn/NiO for Hydrogen Sulfide Detection.

Amorphous metal oxide semiconductor (MOS) materials are endowed with great promise to modulate electronic structures for gas-sensing performance improvement. However, the elevated-temperature requirement of gas sensors severely impedes the application of amorphous materials due to their low thermal stability. Here, a cationic-assisted strategy to tailor the Ni-O microenvironment in an amorphous-dominated Zn/NiO heterogeneous structure with high thermal stability was developed. It was found that 6 mol % Zn incorporation into amorphous NiO can effectively preserve the amorphous-dominated NiO phase even at high temperature. After calcination, the amorphous oxide can only be converted to crystals partly thus leading to the formation of amorphous/crystalline compounds, and the content of the amorphous phase can be adjusted by changing the calcination temperature. This amorphous/crystalline configuration can induce more electron transfer from Ni to Zn species, leading to the formation of active Niδ+ (δ>2) centers. Ex situ XPS and in situ Raman spectroscopy studies proved that the generated Niδ+ species pronouncedly promote the electron transfer during the H2S adsorption process. The amorphous/crystalline-6 mol % Zn/NiO sensor exhibits exceptional hydrogen sulfide response (2 ppm, 3.23), outstanding repeatability (as long as 5 weeks), and low limit of detection (as low as 50 ppb), surpassing most reported nickel-based gas sensors such as the crystal nickel oxide prepared in this work. The response and detection limit of the latter is only (2 ppm, 1.89) and (0.05 ppm) respectively. Our work thus opens up more opportunities for fundamental understanding and modulating of highly active amorphous sensing materials.

A Near-Infrared Fluorescent Probe with Large Stokes Shift for Sensitive Detection of Hydrogen Sulfide in Environmental Water, Food Spoilage, and Biological Systems.

Hydrogen sulfide (H2S) is an important endogenous gas transmitter that plays a critical role in various physiological and pathological processes and can also cause a negative impact on foodstuffs. In this study, we designed and synthesized a simple, easily available, high-yield, and low-cost near-infrared (λem = 710 nm) fluorescent probe, DEM-H2S, with a substantial Stokes shift (205 nm) for the detection of H2S. DEM-H2S features high selectivity and sensitivity (LOD = 80 nM) toward H2S, accompanied by a noticeable color change. Upon interaction with H2S, DEM-H2S exhibits a restored ICT (Intramolecular Charge Transfer) process, thereby manifesting near-infrared fluorescence. DEM-H2S has been successfully utilized to detect H2S in actual water samples and to monitor the spoilage of food items, such as pork, shrimp, and eggs. Furthermore, DEM-H2S enables the imaging of endogenous and exogenous H2S in living MCF-7 cells and zebrafish. Hence, DEM-H2S provides an attractive method for the detection of H2S in environmental, food, and biological systems, holding potential value in physiological and pathological research.

Benzylic Trifluoromethyl Accelerates 1,6-Elimination Toward Rapid Probe Activation.

Activity-based detection of hydrogen sulfide in live cells can expand our understanding of its reactivity and complex physiological effects. We have discovered a highly efficient method for fluorescent probe activation, which is driven by H2S-triggered 1,6-elimination of an α-CF3-benzyl to release resorufin. In detecting intracellular H2S, 4-azido-(α-CF3)-benzyl resorufin offers significantly faster signal generation and improved sensitivity compared to 4-azidobenzyl resorufin. Computed free energy profiles for the 1,6-elimination process support the hypothesis that a benzylic CF3 group can reduce the activation energy barrier toward probe activation. This novel probe design allows for near-real-time detection of H2S in HeLa cells under stimulation conditions.