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A novel “turn-on” mitochondria-targeting near-infrared fluorescent probe for determination and bioimaging cellular hydrogen sulfide
摘要： Hydrogen sulfide (H2S) has been regarded as an important gas transmitter playing vital role in cytoprotective processes and redox signaling. It is very meaningful to monitor and analyze it in biosystem for obtaining important physiological and pathological information. Despite numerous fluorescent probes for cellular H2S have been reported in past decades, only a few have capability to detect mitochondrial H2S with near-infrared (NIR) emission. Therefore, a new mitochondria-targeting NIR fluorescent probe (Mito-NSH) for detection of cellular H2S was developed by introducing 2,4-dinitrophenyl ether into a novel dye (Mito-NOH). A large "turn-on" NIR fluorescence response was obtained due to thiolysis of ether to hydroxyl group when Mito-NSH was treated with NaHS. Moreover, Mito-NSH could quantitatively detect H2S at concentration ranging from 0 to 30 μM with a detection limit of 68.2 nM, and it exerts some superior optical properties, such as large stokes shift (107 nm), highly selectively mitochondria location, fast response and high selectivity to H2S. More impressively, it was successfully applied to imaging exogenous and endogenously generated H2S in living HeLa cells via confocal fluorescence microscopy.
关键词： Fast response,NIR fluorescent probe,"Turn-on" response,Hydrogen sulfide,Mitochondria-targeting
更新于2025-09-23 15:23:52
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Developing cysteamine-modified SERS substrate for detection of acidic pigment with weak surface affinity
摘要： In this paper, we developed cysteamine-modified surface-enhanced Raman scattering (SERS) substrate for detecting detect trace amount of acidic pigment that shows weak affinity with gold nanoparticles (Au NPs). To realize sensitive and reproducible detection of pigment with weak affinity, the SERS substrate was prepared by attaching cysteamine (CA) to the Au NPs, the acidic pigment molecule could rapidly reached to the surface of Au NPs because of the formation of multi-hydrogen-bond and electrostatic interaction between the pigment and CA molecule. The proposed method allowed us to detect five kinds of acidic pigment with a limit of 1.0 ppm, which is below the strictest safety limit. Compared with the previous methods, the advantages of the present substrate were its simple substrate preparation, high reproducibility and good universality. Furthermore, the reliable and enough accurate results had been obtained by using of the proposed substrates in the assay of trace pigment in real samples.
关键词： surface-enhanced Raman scattering,hydrogen bond interaction,cysteamine-modified,acidic pigment,weak affinity
更新于2025-09-23 15:23:52
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Hydrogen production via a novel two-step solar thermochemical cycle based on non-volatile GeO2
摘要： Encouraged by recent advances in solar-chemical fuel production, a moderately high-temperature solar thermochemical cycle based on GeO2/Ge is investigated thermodynamically. Since the GeO2/Ge redox has a great oxygen exchange capacity and suffers unfavorable phase change at high temperature, methanothermal reduction is introduced to lower the operation temperature below melting point of redox. The calculated results indicate that reduction conditions of 875 K < T_red < 1200 K and CH4:GeO2 = 2:1 are conducive to achieving high selectivities of H2 and CO. As for the oxidation step, the H2O:Ge ratio of 8:1 is found abundant enough to ensure complete reoxidation of Ge. Isothermal and non-isothermal solar-to-fuel efficiency (η_solarfuel) are compared, where η_solarfuel of 0.47 and isothermal η_solarfuel of 0.28 respectively. In addition, the preferred site of CH4 adsorbing on GeO2 is predicted, and the calculated adsorption energy is lower than that of SnO2, indicating that GeO2 could be a suitable material for substrate before methanothermal reduction.
关键词： Non-volatile redox,Isothermal and nonisothermal operation,Syngas production,Hydrogen production,GeO2/Ge based solar-chemical cycle
更新于2025-09-23 15:23:52
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Construction of a Novel Fluorescent Probe for On-site Measuring Hydrogen Sulfide Levels in Food Samples
摘要： Hydrogen sulfide (H2S) has been involved in many foodstuffs and beverages. On-site measuring the H2S level in food samples was beneficial to the concerns about food safety and food quality. Herein, we rationally constructed a novel fluorescent probe to track the H2S levels in various food samples. The optical experiments indicated that the probe displayed highly selective and sensitive response to H2S. In addition, the probe can function well in a wide pH value condition, providing a reliable platform to sense H2S. The practical application demonstrated that the probe was applied for tracking H2S levels in banana, grape, and vinegar for the first time. Importantly, by fabricating test strips, the probe was first served to monitor the released H2S in raw meat without relying on elaborate instrumentation. Thus, the probe could be employed as a simple tool to measure the H2S levels in various food samples, as well as to monitor the fresh-like quality of raw meat under on-site conditions.
关键词： Fluorescent probe,On-site measurement,Hydrogen sulfide,Food sample,Test strip
更新于2025-09-23 15:23:52
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Porous SiO2-coated Au-Ag alloy nanoparticles for the alkyne-mediated ratiometric Raman imaging analysis of hydrogen peroxide in live cells
摘要： We prepared an ultrathin porous silica shell-coated Au-Ag alloy nanoparticle (AuAg@p-SiO2NP) and developed it as a novel alkyne-based surface-enhanced Raman scattering (SERS) nanoprobe for the ratiometric Raman imaging of exogenous and endogenous H2O2 in live cells. The AuAg@p-SiO2NPs functionalized with 4-mercaptophenylboronic acid (MPBA) and 4-mercaptophenylacetylene (MPAE, 1,986 cm-1) as internal standard were first incubated with dopamine (DA) to incorporate the bridging molecules through the formation of borate bond between DA and MPBA on the surface of nanoparticle. Then, the signaling alkyne molecules of 3-(4-(phenylethynyl) benzylthio) propanoic acid (PEB, 2,214 cm-1) were conjugated to the surface of nanoparticle through the formation of amide bond between the carboxyl group on the PEB and the amino group on the DA, forming the ratiometric SERS nanoprobe. In the presence of H2O2, the alkynyl on the PEB is released from the surface of the Au-Ag alloy nanoparticle due to the boronate-to-phenol switch, decreasing the Raman signal at 2,214 cm-1 significantly. Since the Raman signal of MPAE at 1,986 cm-1 remains unchanged, quantitative analysis of H2O2 concentration can be achieved based on the ratiometric value of I1986/I2214. Under the optimized conditions, the plot of the ratiometric value of I1986/I2214 versus the H2O2 concentration in the range from 0.12 to 8 m M revealed a good linear response with a detection limit of 52 nM based on a signal-to-noise ratio of S/N = 3. The porous SiO2-coated Au-Ag alloy nanoparticle provides a novel SERS substrate with excellent biocompatibility, high stability, and effective anti-interference ability. Together with the alkynyl derivatives as internal standard, the SERS nanoprobe reported here allows the ratiometric detection of H2O2 in live cells and can be further applied to quantify many other biomolecules by using different signaling agents.
关键词： porous SiO2-coated Au-Ag alloy nanoparticle,SERS,alkyne,cell imaging,hydrogen peroxide
更新于2025-09-23 15:23:52
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Conjugated donor-acceptor polymer photocatalysts with electron-output “tentacles” for efficient hydrogen evolution
摘要： The tunable structures and versatile properties for conjugated polymers (CPs) make them viable as a molecular platform for photocatalytic water splitting. Normally, structure design of polymer photocatalyst is focus on tuning its optical band structure or charge-separation ability, the importance of electron-output ability in photocatalytic process is always ignored. This study demonstrates a molecular engineering strategy by introducing an electron-output “tentacle” site, i.e. dibenzothiophene-S,S-dioxide (FSO) unit, into the polymer backbone to construct a series of donor-acceptor type conjugated polymer photocatalysts for efficient hydrogen evolution, which not only results in optimized light absorption ability and excellent exciton-separation, but also leads to the efficient electron-output ability. Detailed DFT calculations further theoretically confirm the vital role of FSO unit as an electron-output “tentacle” site.
关键词： Conjugated polymer,Electron-output “tentacles”,Artificial photosynthesis,Hydrogen evolution,Photocatalysis
更新于2025-09-23 15:23:52
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Perovskite photocatalyst CsPbBr3-xIx with a bandgap funnel structure for H2 evolution under visible light
摘要： A simple and efficient light-assisted method is employed to prepare powder samples of all-inorganic mixed-perovskite CsPbBr3-xIx from CsPbBr3 by ion exchange in aqueous HBr/KI solution such that the concentration of I in a sample particle decreases on going from the surface to the interior. CsPbBr3-xIx/Pt, namely, CsPbBr3-xIx samples loaded with Pt nanoparticles, shows a high performance for the hydrogen evolution under visible-light irradiation in aqueous HBr solution saturated with CsPbBr3. The H2 evolution rate of the CsPbBr3-xIx/Pt powders (200 mg) is determined to be 224 μmol h-1, under 120 mW cm-2 visible-light (λ ≥ 420 nm) illumination. The CsPbBr3-xIx samples have a high stability, with no apparent decrease in the catalytic activity after 50 h of repeated H2 evolution experiments. The apparent quantum efficiency of CsPbBr3-xIx/Pt is determined to be 2.15% under the irradiation of 450 nm light.
关键词： photocatalysis,hydrogen evolution,bandgap funnel,all-inorganic perovskite,halide gradient
更新于2025-09-23 15:23:52
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MgO/g-C3N4 nanocomposites as efficient water splitting photocatalysts under visible light irradiation
摘要： A series of MgO/g-C3N4 nanocomposites was prepared by calcination of the mixture of magnesium nitrate hexahydrate and g-C3N4, and applied as photocatalysts for hydrogen evolution from water splitting. The results demonstrate that the MgO/g-C3N4 nanocomposites can effectively harvest sunlight to produce hydrogen from water with higher photocatalytic efficiency than the bare g-C3N4. A high hydrogen evolution rate (HER) of 30.1 μmol h-1 was achieved under visible light for the MgO/g-C3N4 composite loaded with 1 wt% MgO, which is much higher than that of the bare g-C3N4 (5.76 μmol h-1). The enhanced photocatalytic activity of the MgO/g-C3N4 composite could be attributed to the formation of heterojunction between g-C3N4 and MgO that promotes the photo-induced charge carriers' transmission and separation.
关键词： photocatalysis,MgO/g-C3N4 nanocomposite,heterojunction,hydrogen evolution
更新于2025-09-23 15:23:52
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Revealing the role of kapok fibre as bio-template for In-situ construction of C-doped g-C3N4@C, N co-doped TiO2 core-shell heterojunction photocatalyst and its photocatalytic hydrogen production performance
摘要： For the first time, C-doped g-C3N4@C, N co-doped TiO2 core-shell heterojunction photocatalyst was successfully prepared by an in-situ one-pot hydrothermal bio-template approach, assisted by calcination treatment at 500?°C. Kapok fibre was used as a bio-templates and in-situ C doping in g-C3N4 and TiO2 during the formation of core-shell heterojunction photocatalyst. Moreover, the used of urea as g-C3N4-precursor also contribute to band-gap narrowing by an in-situ carbon and nitrogen doping in TiO2. Various characterisation techniques were employed to understand the effect TiO2 precursor concentration on the evolution of core-shell nanostructure heterojunction photocatalyst that can affect and boost the catalytic activity. The detailed understanding of the concurrent growth of C-doped g-C3N4 (CCN) and C, N co-doped TiO2 mechanism, as well as the formation of core-shell nanostructures heterojunction formation, are also proposed in this study. Our finding indicated that the bio-template core-shell nanostructure heterojunction photocatalysts showed a dramatic increase in photoinduced electron-hole separation efficiency as demonstrated by the photoelectrochemical and photoluminescence analyses. The enhancement in photogenerated charge carrier separation and narrower band gap resulted in superior photocatalytic activities with the highest rate of hydrogen production was recorded by CCN/T-1.5 sample (625.5 μmol h-1 g-1) in methanol aqueous solution. The well-developed interconnected heterojunction formation with appropriate CCN and TiO2 contents in core-shell nanoarchitectures system is a prime factor for the future design of a highly efficient visible-light-driven photocatalyst.
关键词： Bio-template,Heterojunction photocatalyst,Core-shell,Co-doping,Photocatalytic hydrogen production,Visible light
更新于2025-09-23 15:23:52
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Carbon Nanotube-Supported Cu <sub/>3</sub> P as High-Efficiency and Low-Cost Cocatalysts for Exceptional Semiconductor-Free Photocatalytic H <sub/>2</sub> Evolution
摘要： Developing an inexpensive and high-efficiency hydrogen-production cocatalyst to replace the noble metal Pt remains a big challenge in the fields of sustainable photocatalytic hydrogen evolution. Herein, we report the exploration of a high-efficient binary noble metal free Cu3P-CNT H2-evolution cocatalyst by direct high-temperature phosphatizing of Cu(OH)2-CNT. Impressively, combining the advantages of noble metal free Cu3P and carbon nanotube (CNT), the binary Cu3P-CNT cocatalysts show high-efficient photocatalytic H2 evolution in Eosin Y(EY)-contained semiconductor-free photocatalytic systems. The maximum visible-light H2-generation rate for promising EY-Cu3P-CNT systems was 17.22 mmolg-1h-1. The highest apparent quantum efficiency (AQE) could reach 10.23% at 500 nm. More importantly, we found that the separation of photogenerated electrons and holes in the Eosin Y, the efficiency of electron transfer from EY to the active edge sites of Cu3P, and the electrocatalytic H2-evolution activity of Cu3P, could be simultaneously boosted via readily adding the conductive CNT, thus achieving the significantly improved photocatalytic H2 evolution. This work provides a simple and facile strategy to design highly efficient semiconductor-free photocatalytic proton-reduction systems using high-activity transition metal phosphides (TMPs) and inexpensive carbon nanomaterials.
关键词： Photocatalytic Hydrogen Evolution,noble metal-free Cu3P Co-catalysts,Solar Fuel,Carbon nanotube (CNT),Dye sensitization
更新于2025-09-23 15:23:52