Selective and sensitive molecular probes for hydrogen peroxide (H2O2), which plays diverse roles in oxidative stress and redox signaling, are urgently needed to investigate the physiological and pathological effects of H2O2. A lack of reliable tools for in vivo imaging has hampered the development of H2O2 mediated therapeutics. By combining a specific tandem Payne/Dakin reaction with a chemiluminescent scaffold, H2O2-CL-510 was developed as a highly selective and sensitive probe for detection of H2O2 both in vitro and in vivo. A rapid 430-fold enhancement of chemiluminescence was triggered directly by H2O2 without any laser excitation. Arsenic trioxide induced oxidative damage in leukemia was successfully detected. In particular, cerebral ischemia-reperfusion injury-induced H2O2 fluxes were visualized in rat brains using H2O2-CL-510 , providing a new chemical tool for real-time monitoring of H2O2 dynamics in living animals. 相似文献
A novel aptamer‐based CE with chemiluminescence (CL) assay was developed for highly sensitive detection of human immunoglobulin E (IgE). The IgE aptamer was conjugated with gold nanoparticles (AuNPs) to form AuNPs‐aptamer that could specifically recognize the IgE to produce an AuNPs‐aptamer‐IgE complex. The mixture of the AuNPs‐aptamer‐IgE complex and the unbounded AuNPs‐aptamer could be effectively separated by CE and sensitively detected with luminol‐H2O2 CL system. By taking the advantage of the excellent catalytic behavior of AuNPs on luminol‐H2O2 CL system, the ultrasensitive detection of IgE was achieved. The detection limit of IgE is 7.6 fM (S/N = 3) with a linear range from 0.025 to 250 pM. Successful detection of IgE in human serum samples was demonstrated and the recoveries of 94.9–103.2% were obtained. The excellent assay features of the developed approach are its specificity, sensitivity, adaptability, and very small sample consumption. Our design provides a methodology model for determination of rare proteins in biological samples. 相似文献
A label‐free, non‐derivatization chemiluminescence resonance energy transfer (CRET) detection platform has been developed for the detection of the non‐fluorescent small molecule 6‐mercaptopurine. This CRET process arose from a chemiluminescent (CL) donor–acceptor system in which the reaction of bis(2,4,6‐trichlorophenyl)oxalate (TCPO)–H2O2–fluorescein (maximum emission at 521.6 nm) served as the donor and gold nanoparticles (AuNPs, maximum absorption at 520.0 nm) served as the acceptor. This process caused a significant decrease in the CL signal of the TCPO–H2O2–fluorescein reaction. The presence of 6‐mercaptopurine induced an aggregation of AuNPs with the assistance of Cu2+ ions through cooperative metal–ligand interactions that was accompanied by a distinct change in color and optical properties. The maximum absorption band of the AuNPs was red‐shifted to 721.0 nm and no longer overlapped with the CL spectrum of the reaction; as a result, the CL signal was restored. This CRET system exhibited a wide linear range, from 9.0 nmol L?1 to 18.0 μmol L?1, and a low detection limit (0.62 nmol L?1) for 6‐mercaptopurine. The applicability of the proposed CRET system was evaluated by analysis of 6‐mercaptopurine in spiked human plasma samples. 相似文献
In this work, cerium oxide nanoparticles are capable of strongly enhancing the chemiluminescence (CL) of the luminol–hydrogen peroxide (H2O2) system. Based on this, a microarray CL method for the determination of the removal rate constant of H2O2 by human erythrocytes has been developed. It is providing direct evidence for a H2O2-removing enzyme in human erythrocytes that acts as the predominant catalyst. A reaction mechanism is discussed. The proposed microarray CL method is sensitive, selective, simple and time-saving, and has good reproducibility and high throughput. Relative CL intensity is linearly related to the concentration of H2O2 in the range from 0.01 to 50 μM. The limit of detection is as low as 6.5?×?10?11 M (3σ), and the relative standard deviation is 2. 1 % at 1 μM levels of H2O2 (for n?=?11). 相似文献
Establishing a simple and accurate method for Hg2+ detection is of great importance for the environment and human health. In this work, platinum nanoparticles (Pt NPs) with different capped agents and morphologies were synthesized. It was found that Pt NPs exhibited peroxidase‐like activity that can catalyze the chemiluminescence (CL) of the luminol system without H2O2. The most intensive CL signals were obtained by using PVP‐capped Pt NPs as catalysis. Based on the fact that Hg2+ could further enhance the CL intensity in the Pt NPs‐luminol CL system, a Pt NPs‐catalyzed CL method based on a flow injection system is developed for the sensitive analysis of Hg2+. When the concentration of Hg2+ in the system increases, the CL intensity would together increase, thereby achieving sensitive Hg2+ detection. The limit of detection (LOD) was calculated to be 8.6 nM. This developed method provides a simple and rapid approach for the sensitive detection of Hg2+ and shows great promise for applications in other complex systems. 相似文献
Oxidative stress is considered as an important factor and an early event in the etiology of Alzheimer's disease (AD). Cu bound to the peptide amyloid‐β (Aβ) is found in AD brains, and Cu‐Aβ could contribute to this oxidative stress, as it is able to produce in vitro H2O2 and HO. in the presence of oxygen and biological reducing agents such as ascorbate. The mechanism of Cu‐Aβ‐catalyzed H2O2 production is however not known, although it was proposed that H2O2 is directly formed from O2 via a 2‐electron process. Here, we implement an electrochemical setup and use the specificity of superoxide dismutase‐1 (SOD1) to show, for the first time, that H2O2 production by Cu‐Aβ in the presence of ascorbate occurs mainly via a free O2.? intermediate. This finding radically changes the view on the catalytic mechanism of H2O2 production by Cu‐Aβ, and opens the possibility that Cu‐Aβ‐catalyzed O2.? contributes to oxidative stress in AD, and hence may be of interest. 相似文献
The authors report that carbon nitride quantum dots (CN QDs) exert a strong enhancing effect on the Cu(II)/H2O2 chemiluminescent system. Chemiluminescence (CL) intensity is enhanced by CN QDs by a factor of ~75, while other carbon nanomaterials have a much weaker effect. The possible mechanism of the effect was evaluated by recording fluorescence and CL spectra and by examining the effect of various radical scavengers. Emitting species was found to be excited-state CN QDs that produce green CL peaking at 515 nm. The new CL system was applied to the sensitive detection of H2O2 and glucose (via glucose oxidase-catalyzed formation of H2O2) with detection limits (3σ) of 10 nM for H2O2 and 100 nM for glucose. The probe was employed for glucose determination in human plasma samples with satisfactory results.
Graphical abstract The effect of carbon nitride quantum dots (CN QDs) on Cu(II)-H2O2 chemiluminescence reaction was studied and the new CL system was applied for sensitive detection of glucose based on the glucose oxidase (GOx)-catalyzed formation of H2O2.
Using the hemin‐H2O2‐Na2CO3‐NaOH chemiluminescence (CL) system, the study on the photodecomposition behavior of hemin under ultraviolet light and solar light were carried out and the determination of hemin was developed coupled with simple flow injection technique. The results showed that the decomposition reaction of hemin in different light irradiations corresponded with a first‐order reaction. And then the determination of hemin was completed by the CL emission from the reaction of hemin with H2O2 in aqueous carbonate. The linear range was 2.2 × 10?10 to 6.88 × 10?7 M and the detection limit was 2.2 × 10?11 M (S/N = 3). The relative standard deviation (RSD) was 2.82% for ten independent detections of 1.72 × 10?8 M hemin. As a preliminary application, the proposed method was successfully applied for the analysis of hemin in pharmaceutical formulations and animal blood with a recovery of 96?108%. A possible CL mechanism of the present system was discussed, and free radicals were suggested to be involved in this reaction. 相似文献
Hydrogen peroxide and hydroxyl radical, both important members of the reactive oxygen species (ROS) family, can cause serious oxidative damages in biological systems. In order to proclaim and prevent oxidation stress, researches on the biomolecule oxidation induced by H2O2 or OH. are in crucial need. However, due to the high reactivity of ROS, traditional methods are difficult to achieve the in situ quantitative investigations on those reactions involving ROS. In this work, using scanning electrochemical microscopy technique (SECM) in a tip generation‐substrate collection mode (TG‐SC), the controllable release and the high‐efficiency collection of electrogenerated H2O2 were achieved. Compared to ex situ fluorescence method, SECM improved the collection efficiency approximately two times larger. Based on it, SECM combined with surface plasmon resonance (SPR) was employed to in situ monitor the protein oxidation (taking Cu12+? MT as a model) induced by H2O2. OH., which was generated from the interaction between H2O2 and Cu12+? MT, can attack the peptide chain and induced the unrepairable protein oxidation damage. The whole process was quantitatively characterized by SPR, and the linear relationship between SPR dip shift and the amounts of released H2O2 was successfully built. Our work proves that the combined SECM‐SPR technique can realize the in situ quantitative determinations of the biomolecule oxidation induced by ROS, which affords an avenue for further elucidation on the mechanisms of oxidation stress in organisms. 相似文献
Carbon monoxide (CO) is proposed as an active pharmaceutical agent with promising pharmaceutical prospects, as it has been involved in multifaceted modulation of diverse physiological and pathological processes. However, questions remain for therapeutic application of inhaled CO attributed to the inherent great affinity between CO and hemoglobin. Therefore, a robust platform with the function of CO transport and controllable release, depending on the local status of an organism, is of prominent significance for effectively avoiding the side effects of CO inhalation and optimizing the biological regulation function of CO. Utilizing the oxidative stress biomarker H2O2 as a trigger and combining with photo‐control, a two‐photon H2O2‐activated CO photoreleaser, FB, featuring highly sensitive and specific H2O2 sensing and photocontrollable CO release, was developed and the vasodilation effect of CO against angiotensin II was demonstrated. 相似文献
Overabundance of hydrogen peroxide originating from environmental stress and/or genetic mutation can lead to pathological conditions. Thus, the highly sensitive detection of H2O2 is important. Herein, supramolecular fluorescent nanoparticles self‐assembled from fluorescein isothiocyanate modified β‐cyclodextrin (FITC‐β‐CD)/rhodamine B modified ferrocene (Fc‐RB) amphiphile were prepared through host–guest interaction between FITC‐β‐CD host and Fc‐RB guest for H2O2 detection in cancer cells. The self‐assembled nanoparticles based on a combination of multiple non‐covalent interactions in aqueous medium showed high sensitivity to H2O2 while maintaining stability under physiological condition. Owing to the fluorescence resonance energy transfer (FRET) effect, addition of H2O2 led to obvious fluorescence change of nanoparticles from red (RB) to green (FITC) in fluorescent experiments. In vitro study showed the fluorescent nanoparticles could be efficiently internalized by cancer cells and then disrupted by endogenous H2O2, accompanying with FRET from “on” to “off”. These supramolecular fluorescent nanoparticles constructed via multiple non‐covalent interactions are expected to have potential applications in diagnosis and imaging of diseases caused by oxidative stresses. 相似文献
A label-free and enzyme-free demultiplexer system for the fabrication of 1:2 molecular demultiplexer with luminol functionalized gold nanoparticles (Lum-AuNPs) as signal transducers was developed for the first time. The Lum-AuNPs had both chemiluminescence (CL) activity and surface plasmon resonance property. It was found that organothiols (RSH) could easily induce the aggregation of AuNPs via strong Au–S covalent interactions in the absence of hydrogen peroxide (H2O2), generating a red shift in the absorption band of AuNPs. However, the presence of H2O2 would readily oxidize RSH to disulfide (RS-SR), and the aggregation of Lum-AuNPs did not occur due to lack of the sulfhydryl group. Meanwhile, H2O2 could react with Lum-AuNPs, producing a strong CL emission owing to the enhancement effect of RSH on AuNPs-luminol-H2O2 CL system. Thus, RSH, H2O2, absorbance ratio, and CL intensity served as the signal input, address input, and two different signal outputs of the 1:2 molecular demultiplexer, respectively. 相似文献
The presence of carbonate or Tris causes a dramatic enhancement in the cheminluminescence (CL) for the oxidation of luminol with hydrogen peroxide catalyzed by microperoxidase 8 (MP8). A nearly constant enhancement in CL was observed over a wide range of H2O2 and luminol concentrations. The enhancement in CL is strongly pH-dependent, varying from 1.3 to 22.2 for carbonate and 1.6 to 10.2 for Tris. The CL enhancement is much more prominent at pH 9-10 than at high pH (>10.5) because of the extremely weak CL emission at pH below 10 when no enhancer is present. The CL enhancement is attributed to an accelerated CL cycle and the existence of alternative routes for luminol CL, possibly involving the carbonate, or Tris radicals. The dramatic enhancement in CL of the MP8-luminol-H2O2 system by the readily available reagents, sodium carbonate or Tris, will have general applications for sensitive CL assays. As an example, the presence of antioxidant results in a diminished and delayed CL emission, allowing the determination of its concentration at sub-micromolar level. 相似文献
The kinetics and mechanisms of the oxidative degradation of 2,4‐dihydroxybenzoic acid (2,4‐DHBA) by the Fenton and photo‐Fenton processes were investigated in detail by a combination of HPLC, IC, and TOC analyses. The formation of 2,3,4‐trihydroxybenzoic acid (2,3,4‐THBA) at an early oxidation stage shows that hydroxylation of the aromatic ring is the first step of the process. This intermediate was able to reduce FeIII and to contribute to the recycling of FeII. Complete mineralization could only be achieved under irradiation (photo‐Fenton). A detailed study of the dependence of the rate of mineralization on the concentration of H2O2 and dissolved O2 was carried out. It was found that, even at a low initial concentration of H2O2, mineralization by the photo‐Fenton process was complete in a relatively short time, provided that the O2 concentration was high enough, indicating that O2 may, at least in part, substitute H2O2. Channeling reaction pathways toward O2 rather than H2O2 consumption is of particular interest for the technical development of the photo‐Fenton process. 相似文献
A highly efficient, metal‐free carbon nanocatalyst is presented that possesses abundant active, oxygenated graphitic edge sites. The edge site‐rich nanocarbon catalyst exhibits about 28 times higher activity for H2O2 production than a basal plane‐rich carbon nanotube with a H2O2 selectivity over 90 %. The oxidative treatment further promotes the H2O2 generation activity to reach close to the thermodynamic limit. The optimized nanocarbon catalyst shows a very high H2O2 production activity, surpassing previously reported catalysts in alkaline media. Moreover, it can stably produce H2O2 for 16 h with Faradaic efficiency reaching 99 % and accumulated H2O2 concentration of 24±2 mm . Importantly, we find that the heterogeneous electron transfer kinetics of the carbon‐based catalyst is closely related to the electrocatalytic activity, suggesting that first outer‐sphere electron transfer to O2 is an important step governing the H2O2 production rate. 相似文献
The oxidative dissolution of silver nanoparticles (AgNPs) plays an important role in the synthesis of well‐defined nanostructured materials, and may be responsible for their activities in biological systems. In this study, we use stopped‐flow spectrophotometry to investigate the kinetics and mechanism of the oxidative dissolution of AgNPs by H2O2 in quasi‐physiological conditions. Our results show that the reaction is first order with respect to both [Ag0] and [H2O2], and parallel pathways that involve the oxidation of H2O2 and HO2? are proposed. The order of the reaction is independent of the size of the AgNPs (≈5–20 nm). The rate of dissolution increases with increasing pH from 6.0 to 8.5. At 298 K and I=0.1 M , the value of kb is five orders of magnitude higher than that of ka (where ka and kb are the rate constants for the oxidative dissolution of AgNPs by H2O2 and HO2?, respectively). In addition, the effects of surface coating and the presence of halide ions on the dissolution rates are investigated. A possible mechanism for the oxidative dissolution of AgNPs by H2O2 is proposed. We further demonstrate that the toxicities of AgNPs in both bacteria and mammalian cells are enhanced in the presence of H2O2, thereby highlighting the biological relevance of investigating the oxidative dissolution of AgNPs. 相似文献
The present study describes a novel and very sensitive electrochemical assay for determination of hydrogen peroxide (H2O2) based on synergistic effects of reduced graphene oxide‐ magnetic iron oxide nanocomposite (rGO‐Fe3O4) and celestine blue (CB) for electrochemical reduction of H2O2. rGO‐Fe3O4 nanocomposite was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X‐ray diffraction (XRD), electrochemical impedance spectroscopy and cyclic voltammetry. Chitosan (Chit) was used for immobilization of amino‐terminated single‐stranded DNA (ss‐DNA) molecules via a glutaraldehyde (GA) to the surface of rGO‐Fe3O4. The MTT (3‐(4,5‐Dim ethylt hiazol‐2‐yl)‐2,5‐diphenylt etrazolium bromide) results confirmed the biocompatibility of nanocomposite. Experimental parameters affecting the ss‐DNA molecules immobilization were optimized. Finally, by accumulation of the CB on the surface of the rGO‐Fe3O4‐Chit/ssDNA, very sensitive amperometric H2O2 sensor was fabricated. The electrocatalytic activity of the rGO‐Fe3O4‐Chit/DNA‐CB electrode toward H2O2 reduction was found to be very efficient, yielding very low detection limit (DL) of 42 nM and a sensitivity of 8.51 μA/μM. Result shows that complex matrices of the human serum samples did not interfere with the fabricated sensor. The developed sensor provided significant advantages in terms of low detection limit, high stability and good reproducibility for detection of H2O2 in comparison with recently reported electrochemical H2O2 sensors. 相似文献
Considering that hydrogen peroxide (H2O2) plays significant roles in oxidative stress, the cellular signal transduction and essential biological process regulation, the detection and imaging of H2O2 in living systems undertakes critical responsibility. Herein, we have developed a novel two-photon fluorescence turn on probe, named as Pyp-B for mitochondria H2O2 detection in living systems. Selectivity studies show that probe Pyp-B exhibit highly sensitive response toward H2O2 than other reactive oxygen species (ROS) and reactive nitrogen species (RNS) as well as biologically relevant species. The fluorescence colocalization studies demonstrate that the probe can localize in the mitochondria solely. Furthermore, as a bio-compatibility molecule, the highly selective and sensitive of fluorescence probe Pyp-B have been confirmed by its cell imaging application of H2O2 in living A549 cells and zebrafishes under the physiological conditions. 相似文献