Hydrogen Sulfide Sensor Research Articles

Choice of technological conditions for synthesis of sensing materials based on polyacrylonitrile on flexible substrates

Cd-containing PAN films with modifying additive CdCl2 have been fabricated by pyrolysis under the influence of incoherent infrared radiation under low vacuum conditions using different temperature and time of heat treatment. The influence of modifying additive concentration and of technological conditions on the films electrical and gas sensitive properties have been investigated. AFM-investigation of the films surface morphology has been fulfilled. The technological conditions for the formation process of the sensitive layer material for hydrogen sulphide sensor have been revealed experimentally.

Design of a Smartphone Plastic Optical Fiber Chemical Sensor for Hydrogen Sulfide Detection

We present a low-cost, handheld plastic optical fiber (POF) sensor for hydrogen sulfide (H2S) detection integrated onto a smartphone. The sensor uses smartphone flashlight as a source and camera as a pixel-based intensity detector. The POF is interconnected to the smartphone with a 3-D-printed connector on both source/detector sides. The sensing mechanism is embedded in the fiber link, making the system an all-fiber smartphone architecture. A mobile application handles data acquisition on the Android operative system. The sensor is functionalized for H2S detection through silver deposition on the POF outer surface. Experiments demonstrate the feasibility of the sensor system as the presence of H2S is successfully measured through an increase of optical losses through the POF link. This cost-effective, scalable, and compact sensor is promising for application in environmental sensing.

Trace hydrogen sulfide gas sensor based on tungsten sulfide membrane-coated thin-core fiber modal interferometer

A novel fiber-optic hydrogen sulfide sensor based on a thin-core Mach-Zehnder fiber modal interferometer (TMZFI) is demonstrated and fabricated. This in-line interferometer is composed of a short section of thin-core fiber sandwiched between two standard single mode fibers, and the fast response to hydrogen sulfide is achieved via the construction of tungsten sulfide film on the outside surface of the TMZFI using the dip-coating and calcination technique. The fabricated sensing nanofilm is characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) spectrometer, Fourier transform infrared (FTIR) and spectroscopic analysis technology, etc. Experimental results showed that the WS2 sensing film has a hexagonal structure with a compact and porous morphology. The XPS and FTIR indicate that the existence of two elements (W and S) is demonstrated. With the increasing concentration of hydrogen sulfide, the interference spectra appear blue shift. In addition, a high sensitivity of 18.37 pm/ppm and a good linear relationship are obtained within a measurement range from 0 to 80ppm. In addition, there is an excellent selectivity for H2S, which has also been proved by the surface adsorption energy results of tungsten sulfide with four gases (H2S, N2, O2 and CO2) by using the density functional theory calculations. This interferometer has the advantages of simple structure, high sensitivity and easy manufacture, and could be used in the safety monitoring field of hydrogen sulfide gas.

Copper (II)-mediated fluorescence of lanthanide coordination polymers doped with carbon dots for ratiometric detection of hydrogen sulfide

This work presented a ratiometric sensor for hydrogen sulfide (H2S) based on Cu2+-mediated fluorescence of lanthanide coordination polymers (LnCPs) doped with carbon dots (CDs). The ratiometric sensor (CDs@ZIF-8@GMP/Tb) is fabricated by the self-assembly of terbium ion (Tb3+) and guanosine monophosphate (GMP) on the surface of zeolitic imidazolate framework-8 loaded with CDs (CDs@ZIF-8). In this ratiometric sensor, GMP/Tb moiety was employed as response signal due to the ON-OFF-ON behaviors of Tb3+ fluorescence upon the sequential addition of Cu2+ and H2S, while CDs@ZIF-8 served as reference signal because of the good stability of CDs fluorescence in the presence of Cu2+ or/and H2S. The ratiometric sensor can sensitively detect H2S with a detection limit of 150nM by fluorescent spectrum method and 3μM by naked eyes. Owing to the ultrastrong binding ability of H2S and Cu2+, the ratiometric sensor not only exhibits high selectivity to H2S against other anions, thiols and biological species, which allows detection of H2S in serum sample with satisfied recovery, but also possesses the distinct feature of reversible sensing. We believe that the present study will provide a new insight into the design and application of LnCPs-based ratiometric fluorescent sensors.

Nanomaterials for the Selective Detection of Hydrogen Sulfide in Air.

This paper presents a focused review on the nanomaterials and associated transduction schemes that have been developed for the selective detection of hydrogen sulfide. It presents a quite comprehensive overview of the latest developments, briefly discusses the hydrogen sulfide detection mechanisms, identifying the reasons for the selectivity (or lack of) observed experimentally. It critically reviews performance, shortcomings, and identifies missing or overlooked important aspects. It identifies the most mature/promising materials and approaches for achieving inexpensive hydrogen sulfide sensors that could be employed in widespread, miniaturized, and inexpensive detectors and, suggests what research should be undertaken for ensuring that requirements are met.

Frontispiece: Time‐Gated Detection of Cystathionine γ‐Lyase Activity and Inhibition with a Selective, Luminogenic Hydrogen Sulfide Sensor

Lanthanide Probes Hydrogen sulfide (H2S) functions as a signaling second messenger, and inhibition of H2S-producing enzymes may be a promising therapeutic strategy. The emissive lanthanide probe LLPS-LnIII generates strong turn-on luminescence via a unique mechanism. H2S-mediated reduction of an aryl azide moiety triggers an intramolecular cyclization to form a chromophore that sensitizes TbIII or EuIII luminescence. Time-gated detection with LLPS-LnIII enabled high-throughput screening for inhibition of H2S-producing cystathionine γ-lyase. For more details, see the Communication by L. W. Miller et al. on page 752 ff.

Determination of Hydrogen Sulfide by Wavelength-modulated Diode Laser Absorption Spectroscopy

ABSTRACTRapid, accurate, and sensitive determination of hydrogen sulfide was provided by tunable distributed feedback diode laser absorption spectroscopy. The laser wavelength scanning range covered the strongest absorption band of hydrogen sulfide. The absorption line at 1578 nm was used for analytical measurements. A homemade digital lock-in amplifier was used to demodulate the first and the second harmonic signals. Normalization of the second harmonic by the first harmonic signal provided calibration-free measurements so that interferences from light path, circuitry, and source intensity were minimized. A mass flow controller was used to introduce 0–100 ppm hydrogen sulfide for validating the analytical performance. The results demonstrated the linearity of the normalized harmonic signals with concentration with a correlation coefficient of 0.9995. The response time was approximately 3 s. The detection limit by Allan variance was 45 ppb with an integration time of 35 s. The sensitive hydrogen sulfide sensor is suitable for environmental monitoring with real-time detection.

Synthesis and crystal structure of a highly selective colorimetric and fluorometric sensor for hydrogen sulfide.

A novel Cu(II) complex chemosensor for hydrogen sulfide with azo as the colorimetric group has been synthesized. The complex and ligand crystals were obtained and the molecular structures were characterized by X-ray diffraction and Electrospray ionization High resolution mass spectrometer (ESI-HRMS). The photophysical and recognition properties were examined. The complex can recognize S2- , with an obvious color change from yellow to red based on a copper ion complex displacement mechanism. By contrast, no obvious changes were observed in the presence of other anions (AcO- , H2 PO4- , F- , Cl- , Br- and I- ). We present a simple, easily prepared, yet efficient, inorganic reaction-based sensor for the detection of S2- . The complex should have many chemical and analytical applications in the sensing of hydrogen sulfide.

Properties of Hydrogen Sulfide Sensors Based on Thin Films of Tin Dioxide and Tungsten Trioxide

The effect of hydrogen sulfide in the concentration range of 0–100 ppm on the characteristics of thin films of tin dioxide and tungsten trioxide obtained by the methods of magnetron deposition and modified with gold in the bulk and on the surface is studied. The impurities of antimony and nickel have been additionally introduced into the SnO2 bulk. An optimal operating temperature of sensors 350°C was determined, at which there is a satisfactory correlation between the values of the response to H2S and the response time. Degradation of the sensor characteristics is investigated in the long-term (~0.5–1.5 years) tests at operating temperature and periodic exposure to hydrogen sulfide, as well as after conservation of samples in the laboratory air. It is shown that for the fabrication of H2S sensors, the most promising are thin nanocrystalline Au/WO3:Au films characterized by a linear concentration dependence of the response and high stability of parameters during exploitation.

A colorimetric sensor for hydrogen sulfide detection using direct inhibition of active site in G-quadruplex DNAzyme

Because of the toxicity of hydrogen sulfide and its important role in various physiological processes, the development of a selective and sensitive hydrogen sulfide sensing method is vital. In this study, a colorimetric method for hydrogen sulfide detection was developed by exploiting the direct inhibition of active site in G-quadruplex DNAzyme by hydrogen sulfide. Hydrogen sulfide inactivates the peroxidase-like activity of PS2.M-hemin G-quadruplex DNAzyme by directly blocking the active site of the DNAzyme, allowing the label-free colorimetric detection of hydrogen sulfide by the naked eye by using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS2−) as a peroxidase substrate. From titration results, the detection limit of this colorimetric hydrogen sulfide sensor was estimated to be 410 nM. In addition, the sensor is highly selective for hydrogen sulfide over various anions and was used to determine hydrogen sulfide concentrations in tap water samples.

Time-Gated Detection of Cystathionine γ-Lyase Activity and Inhibition with a Selective, Luminogenic Hydrogen Sulfide Sensor.

Herein, we report the design, synthesis, and characterization of a lanthanideIII complex-based probe for the time-gated luminescence detection of hydrogen sulfide (H2 S) in aqueous media. The probe's unique sensing mechanism relies on the selective reduction of azide to amine by sulfide, followed by intramolecular cyclization to form a quinolinone. The quinolinone is a sensitizer that absorbs near-UV light and transfers excitation energy to coordinated TbIII or EuIII ions to trigger a strong "turn-on" luminescence response with ms-scale lifetimes characteristic of lanthanide complexes. Using this probe, we developed a robust, high throughput screening (HTS) assay for detecting H2 S generated by cystathionine γ-lyase (CSE), one of the main producers of H2 S in mammalian cells. In a 240-compound screen to identify potential CSE inhibitors, the EuIII analogue of the sensor showed a low false-positive rate and high Z'-factor (>0.7).

High sensitive luminescence metal-organic framework sensor for hydrogen sulfide in aqueous solution: A trial of novel turn-on mechanism

Metal-organic framework (MOF) is a class of crystalline porous solid materials which could be designed as sensors for bioactive molecules. In this study, we illustrated a novel turn-on mechanism based on collapse of MOF structure for luminescence MOF sensors. Taking H2S as an analyte, we validated our mechanism using a specially selected MOF material FeIII-MIL-88-NH2 for H2S sensing. The detection limit towards H2S is about 10μM, which is lower than the reported MOF sensors for H2S designing with other turn-on mechanism.

A photoelectrochemical sensor for hydrogen sulfide in cancer cells based on the covalently and in situ grafting of CdS nanoparticles onto TiO2 nanotubes

A facile photoelectrochemical sensor for the determination of hydrogen sulfide (H2S) is developed. Photocurrent is generated through the grafting of CdS nanoparticles covalently and in situ onto TiO2 nanotubes. The surface of TiO2 nanotubes was modified by a layer of thioglycolic acid (TGA) to introduce thiol groups which can adsorb and immobilize Cd ions. CdS nanoparticles would be formed onto TiO2 nanotubes after treating with exogenous or endogenous H2S. Both the exogenous and H2S released from cancer cells were detected based on the photoelectric properties of CdS nanoparticles. And a wide linear range (10nM–106nM) was achieved with a detection limit of 0.7nM.

An optical sensor for hydrogen sulfide detection in open path using WMS-2f/1f technique

An optical hydrogen sulfide (H2S) sensor based on wavelength modulation spectroscopy with the second harmonic (2f) corrected by the first harmonic (1f) signal (WMS-2f/1f) is developed using a distributed feedback (DFB) laser emitting at 1.578 μm and a homemade gas cell with 1-m-long optical path length. The novel sensor is constructed by an electrical cabinet and an optical reflecting and receiving end. The DFB laser is employed for targeting a strong H2S line at 6 336.62 cm-1 in the fundamental absorption band of H2S. The sensor performance, including the minimum detection limit and the stability, can be improved by reducing the laser intensity drift and common mode noise by means of the WMS-2f/1f technique. The experimental results indicate that the linearity and response time of the sensor are 0.999 26 and 6 s (in concentration range of 15.2—45.6 mg/m3), respectively. The maximum relative deviation for continuous detection (60 min) of 30.4 mg/m3 H2S is 0.48% and the minimum detection limit obtained by Allan variance is 79 μg/m3 with optimal integration time of 32 s. The optical H2S sensor can be applied to environmental monitoring and industrial production, and it has significance for real-time online detection in many fields.

Application of ODEMS (Odorant Dispersion and Emissions Monitoring System) to Measure Odorous Emissions from Composting Plant

Odour annoyance represents a very important issue of societal and industrial perspective. It can be due to the intrinsic character of the odour, its frequency and the moment of the perception. Location of industries depends on their odour acceptability in the neighbourhood. As 13 to 20% of the population in European countries would be annoyed by environmental odours, stringent regulations are being enforced for odor monitoring and recently, several works have been carried out to determine suitable and valuable strategies/methods to limit odor annoyance.Industrial and agricultural activities generate atmospheric pollution and olfactive nuisances due to the emission of a complex mixture of volatile compounds. Hydrogen sulphide (H2S) and ammonia (NH3) are clearly identified within composting plants (Cabrol et al, 2012) and due to their high olfactory impact, have to be monitored as mentioned in a report of the French Environmental and Energy Management Agency (ADEME, 2012).ODEMS is a system composed by a network of miniature and autonomous sensors combined with reversed dispersion (Figure 1) and dispersion (Figure 2) modelling systems and enable to provide reliable spatial and temporal information down to the low ppbv level. The miniaturized cost-effective sensors Cairsens are based on amperometric detection and are developed by Cairpol company. Ammonia and hydrogen sulfide sensors have been deployed within a composting plant for determining the odorous sources and evaluating the real impact on the neighbourhood. After a period of data collection, considering weather conditions, this study revealed that this system is also able to predict the impact of a site-specific activity.

Hybrid SnO₂/TiO₂ Nanocomposites for Selective Detection of Ultra-Low Hydrogen Sulfide Concentrations in Complex Backgrounds.

In this paper, we present a chemiresistive metal oxide (MOX) sensor for detection of hydrogen sulfide. Compared to the previous reports, the overall sensor performance was improved in multiple characteristics, including: sensitivity, selectivity, stability, activation time, response time, recovery time, and activation temperature. The superior sensor performance was attributed to the utilization of hybrid SnO2/TiO2 oxides as interactive catalytic layers deposited using a magnetron radio frequency (RF) sputtering technique. The unique advantage of the RF sputtering for sensor fabrication is the ability to create ultra-thin films with precise control of geometry, morphology and chemical composition of the product of synthesis. Chemiresistive films down to several nanometers can be fabricated as sensing elements. The RF sputtering technique was found to be very robust for bilayer and multilayer oxide structure fabrication. The geometry, morphology, chemical composition and electronic structure of interactive layers were evaluated in relation to their gas sensing performance, using scanning electron microscopy (SEM), X-ray diffraction technique (XRD), atomic force microscopy (AFM), Energy Dispersive X-ray Spectroscopy (EDAX), UV visible spectroscopy, and Kelvin probe measurements. A sensor based on multilayer SnO2/TiO2 catalytic layer with 10% vol. content of TiO2 demonstrated the best gas sensing performance in all characteristics. Based on the pattern relating material’s characteristics to gas sensing performance, the optimization strategy for hydrogen sulfide sensor fabrication was suggested.

Structural effects of naphthalimide-based fluorescent sensor for hydrogen sulfide and imaging in live zebrafish.

Hydrogen sulfide (H2S) is an important biological messenger, but few biologically-compatible methods are available for its detection in aqueous solution. Herein, we report a highly water-soluble naphthalimide-based fluorescent probe (L1), which is a highly versatile building unit that absorbs and emits at long wavelengths and is selective for hydrogen sulfide over cysteine, glutathione, and other reactive sulfur, nitrogen, and oxygen species in aqueous solution. We describe turn-on fluorescent probes based on azide group reduction on the fluorogenic ‘naphthalene’ moiety to fluorescent amines and intracellular hydrogen sulfide detection without the use of an organic solvent. L1 and L2 were synthetically modified to functional groups with comparable solubility on the N-imide site, showing a marked change in turn-on fluorescent intensity in response to hydrogen sulfide in both PBS buffer and living cells. The probes were readily employed to assess intracellular hydrogen sulfide level changes by imaging endogenous hydrogen sulfide signal in RAW264.7 cells incubated with L1 and L2. Expanding the use of L1 to complex and heterogeneous biological settings, we successfully visualized hydrogen sulfide detection in the yolk, brain and spinal cord of living zebrafish embryos, thereby providing a powerful approach for live imaging for investigating chemical signaling in complex multicellular systems.

Electrochemical hydrogen sulfide biosensors.

The measurement of sulfide, especially hydrogen sulfide, has held the attention of the analytical community due to its unique physiological and pathophysiological roles in biological systems. Electrochemical detection offers a rapid, highly sensitive, affordable, simple, and real-time technique to measure hydrogen sulfide concentration, which has been a well-documented and reliable method. This review details up-to-date research on the electrochemical detection of hydrogen sulfide (ion selective electrodes, polarographic hydrogen sulfide sensors, etc.) in biological samples for potential therapeutic use.

H2S optical waveguide gas sensors based on chitosan/Au and chitosan/Ag nanocomposites

In this work we present simple technique to fabricate chitosan based nanocomposite coatings containing Ag and Au nanoparticles and investigate the possibility of using these materials as sensitive layer of optical planar waveguide based nonreversible hydrogen sulfide sensors (chemidosimeters). It is shown that chitosan/Ag and chitosan/Au based sensors allows detection of hydrogen sulfide gas at concentration ranges 0.1–100ppm and 5–300ppm correspondently.

Selective hydrogen sulfide (H2S) sensors based on molybdenum trioxide (MoO3) nanoparticle decorated reduced graphene oxide

This paper investigates a selective method of sensing hydrogen sulfide using molybdenum trioxide (MoO3) nanoparticle decorated graphene oxide (GO). Reduced graphene oxide was synthesized from natural graphite (NG) by the modified Hummer׳s method and decorated with the MoO3 nanoparticles. Sensors were fabricated by the spin coating of MoO3-decorated rGO between Pt electrodes on alumina substrate (Al2O3). In comparison with pristine rGO sensor, the MoO3–rGO chemiresistors have a clear response to hydrogen sulfide down to 50ppm at 70°C. Thermal characterization of the sensor is studied. Results show that the fabricated devices have the maximum gas response at about 160°C. Selectivity tests indicated that these sensors have poor respond to interfering analytes such as ethanol, carbon monoxide and nitric oxide. Furthermore, the effect of MoO3 content and graphene oxide suspension concentration on the sensor response is investigated. Hereby it is shown that the sensor content of 3wt% MoO3 and of 5mg/ml of GO suspension concentration has the highest sensitivity. Decorated reduced graphene oxide chemiresistors offer advantages such as remarkable potential for mass production due to their ease of manufacturing, good performance, and significant selectivity.