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Hydrogen peroxide detection with a silver nanoparticle grating chip fabricated by plasmonic plating
摘要： An optical detection of hydrogen peroxide (H2O2) is proposed, using grating structures of silver nanoparticles (AgNPs). Periodic line structures of AgNPs are deposited on a gold nanoparticle (AuNP)-decorated glass plate using an interference exposure with a green laser beam, based on the plasmonic plating method. This AgNP grating chip diffracts incident light, and the diffraction efficiency is dependent on the amount of AgNPs. By applying a drop of H2O2 solution onto the chip, the diffraction intensity declines due to the autocatalytic decomposition of AgNPs. A portable measurement system of the diffraction intensity change is constructed, and the H2O2 detection in the concentration range 6.7 – 668 μmol/L is performed in 2 min simply by dropping the H2O2 solution onto the substrate.
关键词： silver nanoparticles,plasmonic plating,optical sensor,hydrogen peroxide detection,diffraction grating
更新于2025-11-25 10:30:42
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Luminescence and anion recognition performance of mononuclear Eu(III) complexes with N- and O- donor pyridine derivatives
摘要： A series of Eu(III) complexes with pyridine-2-carboxamide (PCA), pyridine-2-carboxaldoxime (PCAO), pyridine-2,3-dicarboxylic anhydride (PDCA) or pyridine-2-methanol (PM) as primary ligands and 4,4′-dimethoxy-2,2′-bipyridine (DMBP) as ancillary ligand were synthesized. The interaction between the ligands and complexes were confirmed by FT-IR study. The complexes were abbreviated as [Eu(PCA)3DMBP].Cl3 (C1), [Eu(PCAO)3DMBP].Cl3 (C2), [Eu(PDCA)3DMBP].Cl3 (C3) and [Eu(PM)3DMBP].Cl3 (C4). Optical studies were done by UV–vis spectroscopy and PL spectroscopy. The highest intrinsic luminescent quantum yield (53.42%) and lifetime value (1456 μs) were found for C3. Lowest quantum yield was exhibited by C2. Anion sensing studies of all the complexes were done by UV–vis and PL spectroscopy and it was observed that complex C1 showed remarkable change in optical properties upon addition of F? and HSO4? ions. Thus C1 can be used as optical sensor for F? and HSO4? ions. The FQD for F? and HSO4? ions were found to be 6.55 and 3.58 respectively for C1.
关键词： Sensing performance,Antenna effect,Hydrogen bonding,Optical sensor,Lifetime decay
更新于2025-11-21 11:18:25
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A fluorescent probe based on tetrahydro[5]helicene derivative with large Stokes shift for rapid and highly selective recognition of hydrogen sulfide
摘要： In this work, we have designed and synthesized a dinitrobenzene-sulfonate tetrahydro[5]helicene (H-DNP) as an effective fluorescent probe for detection of hydrogen sulfide (H2S). Upon the addition of H2S, a significant fluorescence enhancement (75-fold) at 495 nm can be observed with a distinct color change from colorless to yellow. Additionally, H-DNP shows low background spectroscopic signal, large Stokes Shift up to ~140 nm, good sensitivity, rapid response time less than 2 min, low detection limit (48 nM) and high selectivity towards common bio-thiols (Cysteine, Homocysteine and Glutathione). Compared with the previous dinitrophenoxy tetrahydro[5]helicene, this probe has shorter response time and lower detection limit. Most importantly, this probe H-DNP has low toxicity to cells and excellent cell permeability, which can be applied to visualize H2S in living cells.
关键词： Fluorescence,Cell imaging,Probe,4-dinitrobenzene,Helicene,2,Hydrogen sulfide
更新于2025-11-21 11:08:12
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A sequential and reversibility fluorescent pentapeptide probe for Cu(II) ions and hydrogen sulfide detections and its application in two different living cells imaging
摘要： In this study, we report a sequential and reversibility fluorescent probe (DP5) based on pentapeptide conjugated with dansyl groups using the solid phase peptide synthesis (SPPS) technology. DP5 showed immediate “turn off” response toward Cu2+ ions at an excitation wavelength of 330 nm with detection limits of 23.5 nM. The 2:1 binding ratio between DP5 and Cu2+ were confirmed using Job's plot method and fluorescence titration study, and DP5-Cu complex was observed with an association constant of 6.76 × 108 M?2. As designed, DP5-Cu complex as a promising analytical probe exhibited highly selective for H2S detection in aqueous solutions. The detection limit for H2S was obtained to be 17.2 nM, and lower than EPA and WHO guidelines. In addition, the reversibility and cyclicity were imparted to the DP5 during the detection of Cu2+ and H2S, and cycle effect is very good. Furthermore, DP5 displayed better biocompatibility and low biotoxicity, and sequential fluorescence “on-off-on” responses of DP5 to Cu2+ and H2S were successfully applied in two different living cells.
关键词： Cu2+ ions,Pentapeptide,Fluorescent probe,Cell imaging,Hydrogen sulfide,Aqueous solutions
更新于2025-11-21 11:08:12
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Perylenequinone-based “turn on” fluorescent probe for hydrogen sulfide with a high sensitivity in living cells
摘要： Hydrogen sulfide (H2S) is a kind of gaseous signal molecule in many physiological processes. In order to detect H2S, a novel “turn on” fluorescent probe 6,12-dihydroxyperylene-1,7-dione (DPD) was designed and synthesized. The probe DPD is fluorescence silence, while the addition of H2S induces an obvious green fluorescence with an obvious color change from dark blue to yellow-green. The probe shows excellent selectivity, fast response (2.5 minutes) and linear curve (0-90 μM) in wide effective pH range (4-10). Competition experiments are also revealed in corresponding studies and the detection limit is 3.6 μM. The response mechanism is proved to be the reduction of the probe by H2S, which is confirmed by 1H NMR. Furthermore, through the fluorescence turn-on signal toward H2S in Hela cells, probe DPD was successfully applied to monitor H2S in living Hela cells.
关键词： hydrogen sulfide,probe,fluorescence imaging,cell imaging,perylenequinone
更新于2025-11-21 11:08:12
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A Combined Experimental and Theoretical Insights into the Synergistic Effect of Cerium Doping and Oxygen Vacancies into BaZrO <sub/>3-δ</sub> Hollow Nanospheres for Efficient Photocatalytic Hydrogen Production
摘要： The long-standing debate over the influence of oxygen vacancies and various dopants has been the center point in perovskite-based compounds for their photocatalytic applications. Hydrothermally synthesized Cerium doped BaZrO3 (BZO) hollow nanospheres has been systematically studied by experimental and theoretical calculations to understand the effect of Cerium doping and oxygen vacancies on the photocatalytic properties. Compounds synthesized by a template-free route were composed of hollow nanospheres generated by Ostwald ripening of spherical nanospheres, which were formed by agglomeration of nanoparticles. The high alkaline condition and high temperature during the hydrothermal condition may lead to the formation of local disorders and oxygen vacancies in the compounds, confirmed by ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) analysis and density functional theoretical (DFT) calculations. Combination of oxygen vacancies and progressive doping of Ce onto BZO, BaZr1–xCexO3 (x = 0.00 – 0.04), creates additional energy levels stipulated by vacancy defects and Ce mixed valance states within the band gap of BZO thereby reducing its band gap. The photocatalytic efficacy of the compounds has been examined by photo-driven H2 generation concomitant with oxidation of a sacrificial donor. In this study, BaZr0.97Ce0.03O3 shows the highest efficiency (823 μmol h-1 g-1) with an apparent quantum yield (AQY) of 6% in photocatalytic H2 production among all five synthesized samples. The data obtained from the UV–Vis DRS, XPS, ESR analysis and DFT calculations, the synergistic effect of decreasing the band gap due to Ce doping and the presence of Ce (III)/Ce (IV) pairs along with oxygen vacancies and lattice distortions could be the reasons behind the enhanced photocatalytic efficacy of BaZr1–xCexO3 (x = 0.00 – 0.04) under UV–Visible light.
关键词： Photocatalytic hydrogen production,Cerium doping,Oxygen vacancies,BaZrO3,Hollow nanospheres
更新于2025-11-21 11:01:37
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Hydrogen Induced Etching Features of Wrinkled Graphene Domains
摘要： Wrinkles are observed commonly in CVD (chemical vapor deposition)-grown graphene on Cu and hydrogen etching is of significant interest to understand the growth details, as well as a practical tool for fabricating functional graphene nanostructures. Here, we demonstrate a special hydrogen etching phenomenon of wrinkled graphene domains. We investigated the wrinkling of graphene domains under fast cooling conditions and the results indicated that wrinkles in the monolayer area formed more easily compared to the multilayer area (≥two layers), and the boundary of the multilayer area tended to be a high density wrinkle zone in those graphene domains, with a small portion of multilayer area in the center. Due to the site-selective adsorption of atomic hydrogen on wrinkled regions, the boundary of the multilayer area became a new initial point for the etching process, aside from the domain edge and random defect sites, as reported before, leading to the separation of the monolayer and multilayer area over time. A schematic model was drawn to illustrate how the etching of wrinkled graphene was generated and propagated. This work may provide valuable guidance for the design and growth of nanostructures based on wrinkled graphene.
关键词： graphene,hydrogen etching,wrinkling,CVD synthesis
更新于2025-11-21 11:01:37
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G‐C3N4‐SiC‐Pt for Enhanced Photocatalytic H2 Production from Water under Visible Light Irradiation
摘要： The g-C3N4 and SiC has drawn increasing attention for application to visible light photocatalytic hydrogen evolution from water splitting due to their unique band structure and high physicochemical stability. In this study, g-C3N4-SiC heterojunction with loaded noble metal was constructed. The g-C3N4-SiC-Pt composite photocatalysts were successfully prepared by the combination method of a bio-reduction, sol-deposition and calcination. The layers of g-C3N4 were thinned and the SiC and Pt nanoparticles simultaneously were tightly bound to g-C3N4 by calcination in the process of preparing the g-C3N4-SiC-Pt. The heterojunction formed in the interface of SiC and g-C3N4 enhances the separation efficiency of the photogenerated electron-hole pairs. These composite photocatalysts achieve a high hydrogen evolution rate of 595.3 μmol·h-1·g-1 with a 1wt% of deposited Pt, 3.7- and 2.07-fold higher than g-C3N4-bulk and g-C3N4-SiC under visible-light irradiation with a quantum efficiency of 2.76% at 420 nm, respectively.
关键词： visible light,g-C3N4-SiC-Pt photocatalysts,hydrogen evolution,photocatalysis
更新于2025-11-21 11:01:37
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Few-Layered 1T-MoS2-Modified ZnCoS Solid-Solution Hollow Dodecahedra for Enhanced Photocatalytic Hydrogen Evolution
摘要： Enhancing solar hydrogen production efficiency essentially relies on the modification of low-cost and highly stable photocatalysts with enhanced light-harvesting ability and promoted charge transfer kinetics. Herein, we report a facile synthetic route to modify the performance of a low-cost metal sulfide semiconductor, consisting of the bimetallic metal-organic frameworks (MOFs)-templating and the simultaneous sulfidation of the photocatalyst and loading of MoS2 co-catalyst. The mutual sulfur atom shared by all the transition metal sulfides allowed the formation of ZnCoS solid-solution structure and the stabilization of the metallic 1T-MoS2 phase, contributing to the photocatalytic activity enhancement from several aspects: i) extending the light absorption region from UV to visible and near-infrared light by the incorporation of another transition metal sulfide species, i.e., CoS; ii) achieving abundant catalytically active sites, and high electronic conductivity between the intimately contacted ZnCoS and MoS2 by loading few-layered 1T-MoS2; and iii) further increasing its capability of utilizing the single-photon with relatively higher energy in the UV-visible region by the involvement of a metal-free photosensitizer–Eosin Y (EY). As a consequence, the novel few-layered 1T MoS2-modified hollow Zn0.5Co0.5S rhombic dodecahedra exhibited a high photocatalytic H2 production activity of 15.47 mmol h-1 g-1 with an apparent quantum efficiency of 30.3% at 420 nm and stability with 90% H2 evolution retention even after seven consecutive runs for total 35 h irradiation. This novel approach to prepare advanced materials could be further extended to the phase-controllable preparation of MoS2 and the discovery of other transition metal chalcogenides with high activity and stability in various applications.
关键词： ZnCoS solid-solution,hollow dodecahedra,dye-sensitization,1T-MoS2,photocatalytic hydrogen evolution,MOF-templating
更新于2025-11-21 10:59:37
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Photocatalytic Reforming of Sugar and Glucose into H2 over Functionalized Graphene Dots
摘要： Photocatalytic reforming of biomass into H2 combining with its photosynthesis counterpart constitutes a sustainable carbon cycle that produces a clean solar fuel. This study reports the use of environmentally benign graphene-based photocatalysts to effectively reform sugar and glucose. We produce a catalyst consisting of sulfur and nitrogen codoped graphene oxide dots (SNGODs) by sequentially annealing graphite-derived graphene oxide with sulfur and ammonia, exfoliating the annealed product into dots, and autoclaving the dots in an ammonia solution. The codoping introduces quaternary nitrogen on the graphene basal plane to patch the vacancy defects and the autoclaving creates a conjugation between the nitrogen nonbonding states and the graphitic-π orbital by introducing peripheral amide and amino groups. These functionalization steps enlarge the electron resonance domain, narrowing the bandgap and inducing charge delocalization and separation. Here, when SNGODs deposited with a Pt cocatalyst effectively catalyzed H2 production from aqueous solutions of sugar and glucose under visible light irradiation for more than 80 h. The apparent quantum yields of the reforming of sugar and glucose reach 11% and 7.4%, respectively, under 420-nm monochromatic irradiation. This pioneer study demonstrates the superiority of using carbon-based photocatalysts for biomass reforming and provides a structure-tuning strategy for enhancing the catalytic activity.
关键词： Reforming of sugar,Hydrogen production,Graphene oxide,Reforming of glucose,Photocatalytic reforming
更新于2025-11-20 15:33:11