Organelle targetable fluorescent probes for hydrogen peroxide

Hydrogen peroxide(H_2 O_2), as important products of oxygen metabolism, plays an important role in many biological processes, such as immune responses and cellular signal transduction. However, abnormal production of H_2 O_2 can damage cellular biomolecules, which was closely associated with many diseases.Thus, it is urgent to monitor the level change of H_2 O_2 in living cells, particularly at subcellular levels.Toward this end, a wide variety of H_2 O_2 fluorescent probes have been designed, developed and applied for imaging of H_2 O_2 in subcellular levels. In this review, we highlight the representative cases of H_2 O_2 fluorescent probes with mitochondria, nuclei and lysosomes-targetable ability. The review contains organelle target strategies, structures, fluorescence behavior and biological applications of these probes.     

近红外荧光探针检测金属离子、小分子和生物大分子

荧光探针技术是近年来发展迅速的一种荧光分析方法,具有灵敏度高、选择性好、操作简便和响应迅速等特点,受到环境及生命科学领域的青睐.随着荧光探针技术的发展,近红外一区荧光探针由于具有发射波长长(600～ 900 nm)、对细胞损伤小、组织穿透性强和自发荧光背景低等优点,被广泛应用于细胞、组织等复杂生物体系中生物分子的检测、...     

Design of a novel mitochondria targetable turn-on fluorescence probe for hydrogen peroxide and its two-photon bioimaging applications

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.     

原位合成H2O2在水处理技术中的应用研究进展

从过氧化氢(H₂O₂)的原位生成技术角度总结了近年来利用原位合成H₂O₂处理水中污染物的研究,分析了当前可充当氢源材料的种类及不同的氢源材料对于提高H₂O₂产率的影响,以及不同的催化剂材料和催化反应环境提高H₂O₂利用率对污染处理效果的影响因素,并对原位合成H₂O₂在水处理领域中面临的挑战和发展前景做了展望,从而为该技术的大规模应用提供指导和借鉴。     

A pinacol boronate caged NIAD-4 derivative as a near-infrared fluorescent probe for fast and selective detection of hypochlorous acid

A pinacol boronate caged NIAD-4 derivative was demonstrated to be a near-infrared fluorescent probe for fast and selective detection of hypochlorite over other ROS species.     

Hydrogen peroxide in the marine environment: cycling and methods of analysis

Hydrogen peroxide (H₂O₂) is a key intermediate in many biological and environmental processes and there are a range of analytical methods available for its quantification, e.g. spectrophotometry, fluorimetry, chemiluminescence and electroanalytical techniques. This article focuses on the determination of H₂O₂ in seawater, wherein it is believed to play a significant role in redox reactions and the photochemical oxidation of dissolved organic matter. The cycling of H₂O₂ in seawater and potential approaches to in-situ monitoring are discussed, with particular reference to chemiluminescence techniques.     

MOF derived Co3O4/N-doped carbon nanotubes hybrids as efficient catalysts for sensitive detection of H2O2 and glucose

Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large surface area and good conductivity as highly active and selective catalysts for molecular detection in enzyme-free sensors.Herein,we successfully fabricate hollow frameworks of Co3O4/N-doped carbon nanotubes(Co3O4/NCNTs)hybrids by the pyrolysis of metal-organic frameworks followed by calcination in the air.The as-prepared novel hollow Co3O4/NCNTs hybrids exhibit excellent electrochemical performance for H2O2 reduction in neutral solutions and glucose oxidation in alkaline solutions.As sensor electrode,the Co3O4/NCNTs show excellent non-enzymatic sensing ability towards H2O2 response with a sensitivity of 87.40μA(mmol/L)^-1 cm^-2,a linear range of 5.00μmol/L-11.00 mmol/L,and a detection limitation of 1μmol/L in H2O2 detection,and a good glucose detection performance with 5μmol/L.These excellent electrochemical performances endow the hollow Co3O4/NCNTs as promising alternative to enzymes in the biological applications.     

光照下自然水体生物膜产生H2O2及其对十二烷基苯磺酸钠降解的影响

通过模拟实验研究了不同活性的自然水体生物膜在光照条件下生成过氧化氢(H₂O₂)的反应. 并研究了光照对自然水体生物膜体系中十二烷基苯磺酸钠(SDBS)降解的影响, 结合无生物膜H₂O₂溶液中SDBS的降解实验, 验证了H₂O₂对SDBS降解的作用. 结果表明, 具有生物活性的生物膜可以生成H₂O₂, 而无活性和光合作用受到抑制的生物膜则不能生成H₂O₂; 光照条件下, 生物膜体系中SDBS的降解量明显高于无光照条件下的; 光照和Fe²⁺对H₂O₂降解SDBS有促进作用.     

自然水体生物膜体系中过氧化氢浓度的影响因素

以过氧化氢(H₂O₂)为自然水体生物膜产生的活性氧(ROS)的代表, 通过模拟实验, 研究了水-自然水体生物膜体系中光/暗变化、 生物膜的避光预处理与数量、 有机配体和pH值对体系中H₂O₂浓度的影响. 结果表明, 光照可快速增加体系中H₂O₂浓度, 光照转为无光时体系H₂O₂浓度下降(约为光照时的2/3); 避光预处理会显著降低体系中H₂O₂的产生速率和浓度; 生物膜数量的增减会导致体系H₂O₂浓度的相应增减; 有机配体的存在会使体系内H₂O₂浓度下降(约1/2~1/3); pH=7和5的体系中H₂O₂的浓度高于pH=9的体系(高出约1.5倍). 上述各因素主要通过影响生物膜生产H₂O₂、 H₂O₂自然分解和生物膜去除H₂O₂ 3种作用来影响体系H₂O₂浓度.     

溶解有机质对光照自然水体生物膜体系中H2O2生成的影响

通过模拟实验研究了生物膜胞外聚合物(EPS)和乙二胺四乙酸(EDTA) 2种典型溶解有机质(DOM)成分对自然水体生物膜体系中过氧化氢(H₂O₂)生成特征的影响, 并研究了体系初始pH值、 DOM浓度、 溶解氧(DO)等因素的影响. 结果表明, DOM的存在对自然水体生物膜体系中H₂O₂的生成有明显影响. 光照能促使EPS产生H₂O₂, 而EPS的存在对生物膜产生H₂O₂的直接影响不显著, EPS与生物膜共存体系中的H₂O₂由二者共同产生; EDTA本身不产生H₂O₂, 且对H₂O₂分解影响很小, 但会显著抑制生物膜产生H₂O₂, 且浓度越高抑制作用越明显. 体系pH值、 DOM浓度和DO均能不同程度影响EPS产生H₂O₂及EDTA抑制生物膜产生H₂O₂的作用.     

H2O2-responsive theranostic nanomedicine

This review summarizes and discusses the very-recent developments of H₂O₂-responsive theranostic nanoplatforms for versatile biomedical applications, including diagnostic imaging, attenuating tumor hypoxia, enhancing the therapeutic effi ciency of photodynamic therapy/radiation therapy/chemotherapy and theranostic of inflammation/diabetic. It is highly believed that H₂O₂-responsive theranostic nanomedicine will be extensively developed a new specifi c and effi cient theranostic modality to benefi t the personalized biomedicine in the near future.     

Factors influencing decomposition of H2O2 over supported Pd catalyst in aqueous medium

Since H₂O₂ decomposition can result in selectivity/yield loss in the direct H₂O₂ synthesis process from H₂ and O₂ over supported Pd catalysts, it is important to have an enhanced understanding about the factors affecting the H₂O₂ decomposition reaction. Herein, detailed studies have been undertaken to investigate the influence of different factors, such as (a) nature and concentration of acid in reaction medium, (b) nature and concentration of halide in presence and absence of acid in reaction medium, (c) pretreatment procedures and (d) catalyst modification by incorporation of different halides, on the H₂O₂ decomposition reaction over a 5% Pd/C catalyst in aqueous medium at 25 °C. This study has shown that the H₂O₂ decomposition activity is profoundly influenced by all the above factors. The effectiveness of the acids in suppressing the H₂O₂ decomposition activity decreased in the following order: hydroiodic acid > hydrobromic acid > hydrochloric acid  acetic acid > phosphoric acid > sulfuric acid > perchloric acid. The ability of the acid to decrease the H₂O₂ decomposition activity was found to very strongly depend on the nature of its associated anion. Halides, such as iodide, bromide and chloride were particularly effective in suppressing the H₂O₂ decomposition activity. Oxidation pretreatment of the catalyst was found to strongly suppress its H₂O₂ decomposition activity, while a reduction treatment was found to promote its activity. A gradual decrease in the H₂O₂ decomposition activity of the catalyst was observed with each successive usage due to in situ sub-surface oxidation of Pd by H₂O₂. Halide incorporation either via the reaction medium or prior catalyst modification had a similar qualitative effect on the H₂O₂ decomposition activity.     

Catalysis by hetropoly compounds. Part XXVI. Gas phase synthesis of methyl tert-butyl ether over heteropolyacids

Gas phase synthesis of methyl tert-butyl ether (MTBE) from methanol and isobutylene has been studied with several heteropolyacids at 303–383 K. It was found that a Dawson-type heteropolyacid, H₆P₂W₁₈O₆₂, was much active than Keggin-type heteropolyacids, H_nXW₁₂O₄₀ (X = P, Si, Ge, B, and Co), and other solid acids such as SO²⁻₄/ZrO₂, SiO---Al₂O₃ and H-ZSM-5 at 323 K. Since the acid strength of H₆P₂W₁₈O₆₂ was weaker than H₃PW₁₂O₄₀ and H₄SiW₁₂O₄₀, factors other than the acid strength are important for the catalytic activity. Pseudoliquid phase behavior was demonstrated for H₆P₂W₁₈O₆₂ and H₃PW₁₂O₄₀ by the measurements of the absorption of methanol during the reaction and by the unique pressure dependencies of the rate of synthesis. From the absorption data (the amount and rate), it is concluded that the high catalytic activity of H₆P₂W₁₈O₆₂ is brought about by a high-activity state of the pseudoliquid phase in which controlled amounts of molecule are absorbed and the absorption-desorption is rapid. On the other hand, the pseudoliquid phase of H₃PW₁₂O₄₀ is in a low-activity state absorbing excessive amounts of molecule.     

Development of a triple channel detection probe for hydrogen peroxide

The rapid and reliable measurement of hydrogen peroxide (H₂O₂) is imperative for many areas of technology, including pharmaceutical, clinical, food industry and environmental applications. In this work, a novel multifunctional complex, [Ru(bpy)₂(luminol-bpy)](PF₆)₂ (bpy: 2,20'-bipyridine), was designed and synthesized by incorporating a Ru(II) complex with a luminal group. In the presence of horseradish peroxidase (HRP), reaction of [Ru(bpy)₂(luminol-bpy)]²⁺ with H₂O₂ can be monitored by three sensing channels including photoluminescence (PL), chemiluminiscence (CL) and eletrochemiluminiscence (ECL). The quantitative assays for H₂O₂ in aqueous solutions using [Ru(bpy)₂(Luminalbpy)]( PF₆)₂ as a probe were established with PL, ECL and CL signal output modes, respectively.     

Vc-Functionalized Fe3O4 Nanocomposites as Peroxidase-like Mimetics for H2O2 and Glucose Sensing

A simple and efficient colorimetric biosensing for hydrogen peroxide and glucose with peroxidase-like vitamin C(V_c) functionalized Fe₃O₄ magnetic nanoparticles(V_c/Fe₃O₄MNPs) as a catalyst is reported. Compared with Fe₃O₄ MNPs and other catalysts, V_c/Fe₃O₄ MNPs exhibited superior catalytic properties. Kinetic studies indicated that vitamin C incorporated on Fe₃O₄ MNPs improved the affinity toward H₂O₂. As low as 0.29 μmol/L H₂O₂ can be detected with a wide linear range of 0.5—100 μmol/L H₂O₂; moreover, as low as 0.288 μmol/L glucose can be detected with a linear range of 0.5—25 μmol/L glucose. The detection method was highly sensitive in sensing H₂O₂ and glucose. The robustness of V_c/Fe₃O₄ MNPs rendered them suitable for wide ranging applications.     

光催化氧气还原制备H2O2

H2O2广泛应用于化工和环保领域,其分解的唯一产物是水,有利于生产与自然生态系统的协调可持续发展.工业上H2O2的合成主要是通过蒽醌法间接合成,该方法能耗大,污染环境.而直接由H2与O2混合制备H2O2,具有极大的安全风险,且需要消耗大量H2.通过光催化技术将O2和H2O转化成H2O2的方法,避免了H2与O2的直接混合...     

Design of novel catalyst imbedding heteropoly acids in polymer films: Catalytic activity for ethanol conversion

Membrane-like H₃PMo₁₂O₄₀ or H₅PMo₁₀V₂O₄₀-imbedded polymer films were prepared by blending these materials using a chloroform-methanol mixture as solvent, and they were tested as catalysts for the ethanol conversion reaction in a continuous flow fixed-bed reactor. It was found that the chloroform-methanol mixture itself gave no influence on the catalytic activity of bulk H₃PMo₁₂O₄₀ and H₅PMo₁₀V₂O₄₀. Polysulfone, polyethersulfone and polyphenylene oxide were used as blending polymers in this study. H₃PMo₁₂O₄₀-imbedded polymer films showed a higher catalytic activity than H₃PMo₁₂O₄₀ itself due to uniform and fine dispersion of H₃PMo₁₂O₄₀ through polymer films, but the extent of activity and selectivity was varied according to a kind of polymer materials. It was revealed that H₃PMo₁₂O₄₀ or H₅PMo₁₀V₂O₄₀-imbedded polyphenylene oxide film showed much higher oxidation catalytic activity than the corresponding bulk heteropoly acids. This may be due to the interaction (or bonding) of proton of heteropoly acid with polyphenylene oxide, judging from the fact that glass transition temperature of polyphenylene oxide was increased after blending with heteropoly acid. The catalytic activity of the heteropoly acid imbedded in the same polymer was greatly affected by the composite of heteropoly acid. The permeabilities of reactants through polymer films also affected the product selectivity.     

Optimised hydrothermal synthesis of multi-dimensional hybrid coordination polymers containing flexible organic ligands

In this paper, we summarise our recent research interest in the hydrothermal synthesis and structural characterisation of multi-dimensional coordination polymers. The use of N-(phosphonomethyl)iminodiacetic acid (also referred to as H₄pmida) in the literature as a versatile chelating organic ligand is briefly reviewed. This molecule plays an important role in the formation of centrosymmetric dimeric [V₂O₂(pmida)₂]⁴⁻ anionic units, which were first used by us as building blocks to construct novel coordination polymers. Starting with [V₂O₂(pmida)₂]⁴⁻ in solution, we have isolated [M₂V₂O₂(pmida)₂(H₂O)₁₀] species (where M²⁺ = Mn²⁺, Co²⁺ or Cd²⁺) via the hydrothermal synthetic approach, which were then employed for the construction of [CdVO(pmida)(4,4′-bpy)(H₂O)₂]·(4,4′-bpy)_0.5·(H₂O), [CoVO(pmida)(4,4′-bpy)(H₂O)₂]·(4,4′-bpy)_0.5, [Co(H₂O)₆][CoV₂O₂(pmida)₂(pyr)(H₂O)₂]·2(H₂O) and [Cd₂V₂O₂(pmida)₂(pyr)₂(H₂O)₄]·4(H₂O) by the inclusion of bridging organic ligands in the reactive mixtures, such as pyrazine (pyr) and 4,4′-bipyridine (4,4′-bpy). These materials can contain channel systems, and exhibit magnetic behaviour, not only due to the V⁴⁺ centres but also to the transition metal centres which establish the links between neighbouring dimeric [V₂O₂(pmida)₂]⁴⁻ anionic units. A closely related anionic moiety, [Ge₂(pmida)₂(OH)₂]²⁻, was engineered to allow the study of such crystalline hybrid materials using one- and two-dimensional high-resolution solid-state NMR.     

Synthesis of carbon dots with a tunable photoluminescence and their applications for the detection of acetone and hydrogen peroxide

Carbon dots(CDs) with multi-color emissive properties and a high photoluminescent quantum yield(PLQY) have attracted great attention recently due to their potential applications in chemical,environmental,biological and photo-electronic fields.Solvent-dependent effect in photoluminescence provides a facial and effective approach to tune the emission of CDs.In this study,green emissive nitrogen-doped carbon dots(N-CDs) are synthesized from p-hydroquinone and ethylenediamine through a simple hydrothermal method.The as-prepared N-CDs possess a robust excitation-independent green luminescence and a high PLQY of up to 15.9%.Further spectroscopic characterization indicates that the high PLQY is achieved by the balance of nitrogen doping states and the surface passivation extent in CDs.The N-CDs also exhibit solvent-dependent multi-color emissive property and distinct PLQY in different solvents(the maximum can reach up to 25.3%).Furthermore,the as-prepared N-CDs are applied as fluorescence probes to detect acetone and H2O2 in water.This method has exhibited a low detection limit of acetone(less than 0.1 %) and a quick and linear response to the H_2O_2 with the concentration from 0 to 120 μmol/L.This work broadens the knowledge of applying CDs as probes in the bio and chemical sensing fields.     

Ultraviolet stimulation of hydrogen peroxide production using aminoindazole, diaminopyridine, and phenylenediamine solid polymer complexes of Zn(II)

Hydrogen peroxide (H₂O₂) is a valuable chemical commodity whose production relies on expensive and energy intensive methods. If an efficient, sustainable, and inexpensive solar-mediated production method could be developed from the reaction between dioxygen and water then the use of H₂O₂ as a fuel may be possible and gain acceptance. When concentrated at greater than 10 M, H₂O₂ possesses a high specific energy, is environmentally clean, and is easily stored. However, the current method of manufacturing H₂O₂ via the anthraquinone process is environmentally unfriendly making the unexplored nature of its photochemical production at high concentration from solar irradiation of interest. Towards this end, we studied the concentration and quantum yield of hydrogen peroxide produced in an ultraviolet (UV-B) irradiated environment using solid, Zn(II)-centered, complexes of amino-substituted isomers of indazole, pyridine, and phenylenediamine to catalyze the reaction. Aqueous suspensions in contact with air were exposed to 280–360-nm light from a low-power lamp. Of the ten complexes studied, Zn-5-aminoindazole had the greatest first-day production of 63 mM/day with a 37% quantum yield and p-phenylenediamine (PPAM) showed the greatest long-term stability. Isomeric forms of the catalysts’ organic components (e.g., amino groups) affected H₂O₂ production. For example, irradiation of diaminopyridine isomers indicated 2,3-diamino and 3,4-diamino structures were the most productive, each generating 32 mM/day H₂O₂, whereas the 2,5-diamino isomer generated no H₂O₂. A significant decrease in H₂O₂ production with time was observed for all but PPAM, suggesting the possibility of a catalyst-poisoning mechanism. We propose a reaction mechanism for H₂O₂ production based on the stability of the resonance structures of the different isomers.