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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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Photoelectrochemical Biosensor Based on Co3O4 Nanoenzyme Coupled with PbS Quantum Dots for Hydrogen Peroxide Detection
摘要： A novel kind of hydrogen peroxide (H2O2) photoelectrochemical (PEC) sensor was constructed based on Co3O4 and PbS nanomaterials modified indium tin oxide (ITO) photoelectrode. The Co3O4 nanoparticles, as mimic enzyme of catalase (CAT), can catalyze H2O2 to generate oxygen (O2) in suit. Then the electron acceptor of O2 enhances the cathodic photocurrent of the photoelectrode. The PEC sensor exhibited high sensitivity because of the formation of p-p type heterostructure between PbS and Co3O4 semiconductors. The photocurrent enhancement can be used to detect concentration of H2O2. The calibration plot was linear in the range from 5 to 250 μM and the detection limit was estimated to be 1.2 μM. The results demonstrated the possibility of nanozyme application in PEC biosensors and the substitution of Co3O4 nanozyme for the natural enzyme.
关键词： hydrogen peroxide,PbS,nanozyme,photoelectrochemical biosensor,Co3O4
更新于2025-11-19 16:56:42
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Effects of alcohol addition on decay of sonoluminescence intensity
摘要： The observation of multibubble sonoluminescence (MBSL) during acoustic cavitational bubble collapse is known to be an appropriate approach to obtain physicochemical information about high-temperature and high-pressure sites generated under sonication. MBSL spectra observed when ultrasound is irradiated to Ar-saturated water can be classified into two categories; a continuum spectrum fraction over a wide range of wavelengths, and a clear peak located at around 310 nm, which is assignable to OH. So far, temporal changes in MBSL spectra have been reported in the presence of alcohols, which scavenge radicals generated in the sonochemical reaction [1]. The spectral changes are presumed to be due to gaseous products generated by the ultrasound decomposition of alcohols. The present study was carried out to investigate the correlation between spectral changes and the products of the sonochemical reaction including hydrogen peroxide and gaseous products from alcohols.
关键词： Gaseous product,Hydrogen peroxide,Sonochemistry,Alcohol addition,Sonoluminescence
更新于2025-11-19 16:51:07
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Bifunctional gold nanoclusters enable ratiometric fluorescence nanosensing of hydrogen peroxide and glucose
摘要： The accurate quantification of hydrogen peroxide (H2O2) and glucose is essential significance in clinical diagnosis. Herein a selective and sensitive ratiometric fluorescent nanosensor was developed for the determination of H2O2 and glucose by integrating peroxidase–like catalytic and fluorescent bifunctional properties of glutathione protected gold nanoclusters (GSH–AuNCs). The GSH–AuNCs exhibit inherent peroxidase–like activity and accelerate the decomposition of H2O2 into hydroxyl radicals. The produced hydroxyl radicals oxidize terephthalic acid (TA), a typical non–fluorescent substrate of peroxidase, to a highly fluorescent product hydroxyterephthalate (TAOH). Upon excitation with single–wavelength at 315 nm, dual–emission fluorescence peaks were recorded at 430 and 600 nm simultaneously. The fluorescence signal of TAOH at 430 nm continuously increased with increasing the concentration of H2O2 while the fluorescence signal of GSH–AuNCs at 600 nm remained unchangeable. Based upon on these facts, a ratiometric fluorescent nanosensor was fabricated for H2O2 assay with TAOH as response unit and GSH–AuNCs as reference, respectively. By converting glucose into H2O2 with catalytic oxidation of glucose oxidase (GOx), this nanosensor was further exploited for glucose assay. Under the optimum conditions, the detection limits of 10 nmol/L H2O2 and 20 nmol/L glucose were acquired. The relative standard deviations were less than 5% for both H2O2 and glucose (5.0 μmol/L solution, n = 11). The practicability of the nanosensor was verified by the determination of glucose in human serum samples. This nanosensor can be easily expanded as a general platform for the detection of other substances involving H2O2 produced or consumed.
关键词： Intrinsic peroxidase-like activity,Fluorescent gold nanoclusters,Hydrogen peroxide,Glucose,Ratiometric fluorescence,Nanosensor
更新于2025-11-14 17:03:37
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Construction of a Biosensor Based on a Combination of Cytochrome c, Graphene, and Gold Nanoparticles
摘要： A biosensor based on a combination of cytochrome c (Cyt c), electrochemical reduced graphene oxides (ERGO), and gold nanoparticles (AuNPs) on a glassy carbon electrode (GCE) was fabricated. The proposed biosensor electrode was denoted as GCE/ERGO-Na?on/AuNPs/Cyt c/Na?on, where ERGO-Na?on was deposited by dropping graphene oxides-Na?on mixed droplet ?rst and following electrochemical reduction, AuNPs were directly deposited on the surface of the ERGO-Na?on modi?ed electrode by electrochemical reduction, and other components were deposited by the dropping-dry method. The effect of the deposition amount of AuNPs on direct electrochemistry of Cyt c in the proposed electrode was investigated. The hydrogen peroxide was taken to evaluate the performance of the proposed biosensor. The results showed that the biosensor has great analytical performance, including a high sensitivity, a wide linear range, a low detection limit, and good stability, reproducibility, and reliability.
关键词： gold nanoparticles,cytochrome c,graphene,direct electrochemistry,biosensor,hydrogen peroxide
更新于2025-09-23 15:23:52
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Enzymatic sensor for phenols based on titanium dioxide generating surface confined ROS after treatment with H2O2
摘要： Titanium dioxide (TiO2) is a popular material as host matrix for enzymes. We now evidence that TiO2 can accumulate and retain reactive oxygen species after treatment by hydrogen peroxide (H2O2) and support redox cycling of a phenolic analyte between horseradish peroxidase (HRP) and an electrode. The proposed detection scheme is identical to that of second generation biosensors, but the measuring solution requires no dissolved H2O2. This significantly simplifies the analysis and overcomes issues related to H2O2 being present (or generated) in the solution. The modified electrodes showed rapid stabilization of the baseline, a low noise level, fast realization of a steady-state current response, and, in addition, improved sensitivity and limit of detection compared to the conventional approach, i.e. in the presence of H2O2 in the measuring solution. Hydroquinone, 4-aminophenol, and other phenolic compounds were successfully detected at sub-μM concentrations. Particularly, a linear response in the concentration range between 0.025 and 2 μM and LOD of 24 nM was demonstrated for 4-aminophenol. The proposed sensor design goes beyond the traditional concept with three sensors' generations offering a new possibility for the development of enzymatic sensors based on peroxidases and the formation of ROS on titania after treatment with H2O2.
关键词： Hydroperoxyl species,Titanium dioxide,Horseradish peroxidase,Bioelectrochemistry,Hydrogen peroxide
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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Solid-State Fluorescence-based Sensing of TATP via Hydrogen Peroxide Detection
摘要： Fluorenylboronate ester chromophore-based thin films were investigated for the detection of triacetone triperoxide (TATP) vapors via the decomposition product, hydrogen peroxide. Sensing with a high level of sensitivity was achieved using a fluorescence "turn-on" mechanism based on the significant shifts in the absorption and photoluminescence spectra that occurs when the boronate esters were converted to phenoxides by hydrogen peroxide under basic conditions. The addition of an organic base was found to be critical for achieving fast conversion reactions and the formation of the phenoxide anions. Addition of a nitrile group to the fluorenyl boronate ester moiety improved the stability of the material to photooxidation, increased the photoluminescence quantum yields, and enhanced the absorption and emission shifts to longer wavelengths. In real-time sensing measurements, films comprising the cyanofluorenyl boronate ester moiety and tetra-n-butylammonium hydroxide had a response time to acid-decomposed TATP vapor of seconds and a limit of detection of 40 ppb in 60 s.
关键词： fluorenylboronate ester,triacetone triperoxide,phenoxide,nitrile,fluorescence,hydrogen peroxide
更新于2025-09-23 15:23:52
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In situ electrochemical reduction assisted assembly of a graphene-gold nanoparticles@polyoxometalate nanocomposite film and its high response current for detection of hydrogen peroxide
摘要： The nanocomposite film including polyoxometalate (POM) cluster K28Li5H7P8W48O184·92H2O (P8W48), reduced graphene oxide (rGO) and Au nanoparticles (Au NPs) was successfully fabricated by electrochemical reduction assisted technique. This synthesis was novel, convenient, and environmentally friendly. Moreover, the time of fabricating process was greatly shorten to about 1 hour comparing to that of the traditional method of layer by layer (LbL) self-assembly. The reduced P8W48 was served as reducing agent, stabilizer and bridging molecules simultaneously in the composite film. The structure of the composite material was verified by comprehensive characterization using scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The investigation of the electrocatalysis for H2O2 showed that the {PEI/rGO}-Au@P8W48 modified electrode has high catalytic activity, good sensitivity, good selectivity, low detection limit and fast response. In addition, the result indicated that the electrocatalytic activity of the electrode with Au NPs was better than that of the electrode without Au NPs. The enhanced catalytic property was attributed to the synergistic effect of the rGO, P8W48 and Au NPs.
关键词： graphene,hydrogen peroxide,Au nanoparticles,electrocatalysis,polyoxometalates
更新于2025-09-23 15:22:29
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Kinetic effects and oxidation pathways of sacrificial electron donors on the example of the photocatalytic reduction of molecular oxygen to hydrogen peroxide over illuminated titanium dioxide
摘要： Sacrificial electron donors are frequently used in photocatalytic reactions to enhance the performance of the reaction, typically short-chain alcohols as well as their respective aldehydes and acids are used. This study focuses on the differences between the individual electron donors regarding their oxidation rates, mechanistic pathways, the influence of the intermediates and their direct impact on the H2O2 generation. The individual H2O2 formation rates of 16 different electron donors, photonic and faradaic efficiencies for H2O2 production are carefully discussed. Furthermore, a new multi-reaction pathway for t-butanol oxidation is postulated and critically examined.
关键词： Alcohol oxidation,Reaction kinetics,Reaction pathway,Hydrogen peroxide,Photocatalysis,Sacrificial electron donors
更新于2025-09-23 15:22:29