共查询到20条相似文献,搜索用时 31 毫秒
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Paolo Bertoncello Alasdair J. Stewart Lynn Dennany 《Analytical and bioanalytical chemistry》2014,406(23):5573-5587
This critical review covers the use of carbon nanomaterials (single-wall carbon nanotubes, multi-wall carbon nanotubes, graphene, and carbon quantum dots), semiconductor quantum dots, and composite materials based on the combination of the aforementioned materials, for analytical applications using electrogenerated chemiluminescence. The recent discovery of graphene and related materials, with their optical and electrochemical properties, has made possible new uses of such materials in electrogenerated chemiluminescence for biomedical diagnostic applications. In electrogenerated chemiluminescence, also known as electrochemiluminescence (ECL), electrochemically generated intermediates undergo highly exergonic reactions, producing electronically excited states that emit light. These electron-transfer reactions are sufficiently exergonic to enable the excited states of luminophores, including metal complexes, quantum dots and carbon nanocrystals, to be generated without photoexcitation. In particular, this review focuses on some of the most advanced and recent developments (especially during the last five years, 2010–2014) related to the use of these novel materials and their composites, with particular emphasis on their use in medical diagnostics as ECL immunosensors. 相似文献
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Several [Ru(bpy)3]2+ (bpy = 2,2'-bipyridine and its derivatives) complexes were synthesized and compared electrochemically and spectroscopically in the search for better luminophores for electrochemiluminescence (ECL)-based analytical applications. ECL measurement in [Ru(bpy)3]2+/tripropylamine (TPA) aqueous buffer solutions has led to a conclusion that due to the complexity of the ECL generation process, the photoluminescence efficiency cannot be used to predict ECL intensity and there is no obvious relationship between the photoluminescence quantum yield and the ECL intensity. Under the present experimental condition, when compared with the pristine [Ru(bpy)3]2+, the ethoxycarbonyl-substituted derivative, [Ru(bpy-COOEt)3]2+, one of the most efficient luminophores under photoexcitation, did not generate reasonably intense ECL, whereas luminophores with lower photoluminescence quantum yields demonstrated higher ECL. These findings are useful for further efforts in the search for more efficient ECL luminophores. 相似文献
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Fangshuo Liu Fangxin Du Fan Yuan Shuai Quan Yiran Guan Guobao Xu 《Current Opinion in Electrochemistry》2022
Electrochemiluminescence (ECL) is a powerful technique for bioassays. To meet the growing demand for bioassays, it is necessary to develop new ECL emitters and co-reaction acceleration strategies to improve detection sensitivity and expand the application scope. Carbon nitride nanomaterials and 2D transition metal carbides, as newly emerging carbon-based nanomaterials, have been increasingly used for ECL bioassays due to their attractive optical and electrochemical properties as well as diversity. In this minireview, we summarized the latest advances in ECL bioassays using carbon nitride nanomaterials and 2D transition metal carbides in the past two years. Finally, we briefly discuss the future trends and challenges of carbon-based nanomaterials for ECL bioanalysis. 相似文献
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Analytical applications of electrogenerated chemiluminescence (ECL) are reviewed with emphasis on the years 1997-2000. Recent developments are described for the ECL of organics, metal complexes and clusters, cathodic ECL on oxide covered electrodes, ECL based immunosensors, DNA-probe assays and enzymatic biosensors. Mechanisms are given for polyaromatic hydrocarbons, luminol/hydrogen peroxide, some cathodic ECL reactions and ruthenium complexes with and without co-reactants. New developments and improvements of techniques and instrumentation and their application to analytes are described. The application of ECL for visualisation of electrochemical processes and imaging of surfaces is mentioned. 相似文献
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高灵敏CdTe量子点探针的构建及与金属离子的作用 总被引:1,自引:0,他引:1
采用变性的牛血清白蛋白(dBSA)对水相合成的CdTe量子点进行修饰, 构建了高灵敏金属离子探针, 研究了其对重金属离子的检测性能并对机理进行了探讨. 通过优化反应条件, 合成了具有高量子产率的以巯基乙酸为稳定剂的水溶性CdTe量子点, 并采用变性的牛血清白蛋白分别对不同粒径的CdTe量子点进行修饰, 确定变性的牛血清白蛋白与不同粒径量子点之间的最佳比例. 在纯化变性的牛血清白蛋白修饰的量子点(dBSA-QDs)的基础上, 研究了该量子点与不同金属离子的作用. 结果表明, 量子点经修饰后, 其量子产率、 抗光漂白性及稳定性得到显著提高; 而且dBSA-QDs的荧光可被重金属离子有效猝灭, 与巯基乙酸稳定的量子点(TGA-QDs)相比, 检测灵敏度显著提高. 相似文献
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A unique multilabeling at a single-site protocol of the Ru(bpy)(3)(2+) electrochemiluminescence (ECL) system is proposed. Nanoparticles (NPs) were used as assembly substrates to enrich ECL co-reactants of Ru(bpy)(3)(2+) to construct nanoscale-enhanced ECL labels. Two different kinds of NP substrates [including semiconductor NPs (CdTe) and noble metal NPs (gold)] capped with 2-(dimethylamino)ethanethiol (DMAET) [a tertiary amine derivative which is believed to be one of the most efficient of co-reactants of the Ru(bpy)(3)(2+) system] were synthesized through a simple one-pot synthesis method in aqueous media. Although both CdTe and gold NPs realized the enrichment of ECL co-reactants, they presented entirely different ECL performances as nanoscale ECL co-reactants of Ru(bpy)(3)(2+). The different effects of these two NPs on the ECL of Ru(bpy)(3)(2+) were studied. DMAET-capped CdTe NPs showed enormous signal amplification of Ru(bpy)(3)(2+) ECL, whereas DMAET-capped gold NPs showed a slight quenching effect of the ECL signal. DMAET-capped CdTe NPs can be considered to be excellent nanoscale ECL labels of the Ru(bpy)(3)(2+) system, as even a NP solution sample of 10(-18) M was still detectable after an electrostatic self-assembly concentration process. DMAET-capped CdTe NPs were further applied in the construction of aptamer-based biosensing system for proteins and encouraging results were obtained. 相似文献
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The discharge of heavy metal ions into water resources as a result of human activities has become a global issue. Contamination with heavy metal ions poses a major threat to the environment and human health. Therefore, there is a dire need to probe the presence of heavy metal ions in a more selective, facile, quick, cost-effective and sensitive way. Conventional sensors are being utilized to sense heavy metal ions; however, various challenges and limitations like interference, overlapping of oxidation potential, selectivity and sensitivity are associated with them that limit their in-field applicability. Hence, nanomaterial based chemical sensors have emerged as an alternative substitute and are extensively employed for the detection of heavy metal ions as a potent analytical tool. The incorporation of nanomaterials in sensors increases their sensitivity, selectivity, portability, on-site detection capability and device performance. Nanomaterial based electrodes exhibit enhanced performance because surface of electrode at nano-scale level offers high catalytic potential, large active surface area and high conductivity. Therefore, this review addresses the recent progress on chemical sensors based on different nanomaterials such as carbon nanotubes (CNTs), metal nanoparticles, graphene, carbon quantum dots and nanocomposites for sensing heavy metals ions using different sensing approaches. Furthermore, various types of optical sensors such as fluorescence, luminescence and colorimetry sensors have been presented in detail. 相似文献
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《Electrochemistry communications》2007,9(4):551-557
The hollow spherical CdSe QD assemblies were synthesized via a sonochemical approach that utilizes β-cyclodextrin as a template reagent in aqueous solution. The hollow nanospheres have an average diameter of 70 nm and are found to consist of an assembly of monodispersed 5 nm sized CdSe quantum dots. Following an electrochemical reaction with persulfate ions, strong electrogenerated chemiluminescence (ECL) was observed from the CdSe nanoassemblies suspended in an aqueous solution of pH ⩽ 7.95. The study indicates that the morphology of the 70 nm nanoassembly plays an important role in generating the stable ECL since individually dispersed quantum dots did not exhibit any significant ECL. The unique ECL intensity and stability of the synthesized spherical nanoassemblies could allow for potential sensor applications of CdSe quantum dots in water. 相似文献
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Luminescent sensors incorporating two luminophores, an indicator and a reference, offer many advantages over intensity measurements from sensors made with one indicator dye. Quantum dots have yet to be widely employed as insensitive reference luminophores in such systems. This work describes the use of near-infrared emitting quantum dots in conjunction with a long-lifetime platinum(II) porphyrin phosphor in a microsphere-based, ratiometric oxygen sensor. The process for self-assembly of the nanocomposite system was developed, and the response and photostability of the prototypes were investigated. Results indicate the sensors possess excellent sensitivity (K(SV) = 0.00826 μM(-1)) at oxygen concentrations below 300 μM and were resistant to photobleaching. The sensor luminophores displayed minimal spectral overlap and little interference from excitation light, preventing the need for optical filters. A reversible photoenhancement of the quantum dot signal was also observed when exposed for extended periods of time. This work demonstrates the advantages of incorporating long-wavelength quantum dots into ratiometric intensity sensing schemes and highlights some key limitations that must be considered in their use. 相似文献
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Heteroatom doped carbon dots(CDs) with distinct merits are of great attractions in various fields such as solar cells, catalysis, trace element detection and photothermal therapy. In this work, we successfully synthesized blue-fluorescence and photostability manganese-doped carbon dots(Mn-CDs) with a quantum yield up to 7.5%, which was prepared by a facile one-step hydrothermal method with sodium citrate and manganese chloride. The Mn-CDs is the high mono-dispersity, uniform spherical nanoparticles. The Mn element plays a critical role in achieving a high quantum yield in synthesis of carbon dots, which was confirmed by the structure analysis using XPS and FTIR. Spectroscopic investigations proved that the decent PLQY and luminescence properties of Mn-CDs are due to the heteroatom doped, oxidized carbon-based surface passivation. In addition, the Mn-CDs are demonstrated as promising fluorescent sensors for iron ions with a linear range of 0–500 mmol/L and a detection limit of2.1 nmol/L(turn-off), indicating their great potential as a fluorescent probe for chemical sensing. 相似文献
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Kenneth Chu Jonathan R. Adsetts Prof. Dr. Shuijian He Ziying Zhan Liuqing Yang Jonathan M. Wong David A. Love Prof. Dr. Zhifeng Ding 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(68):15892-15900
Artificial lighting sources are one of the most important technological developments for our modern lives; the search for cost-effective and efficient luminophores is therefore crucial to a sustainable future. Graphene quantum dots (GQDs) are carbon-based nanomaterials that exhibit exceptional optical and electronic properties, making them a prime candidate for a luminophore in a light-emitting device. Nitrogen-doped GQDs fabricated from a facile top-down electrochemical exfoliation process with a nitrogen-containing electrolyte in this report showed strong photoluminescent emission at 450 nm, and electrogenerated chemiluminescence at 660 nm in the presence of benzoyl peroxide as a coreactant. When introduced into solid-state light-emitting electrochemical cells, for the first time, the GQDs displayed a broad white emission centered at 610 nm, corresponding to Commision Internationale de l'eclairage (CIE) colour coordinates of (0.38, 0.36). 相似文献
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Due to strong photoluminescence, extraordinary photostability, excellent biocompatibility, and good water-solubility, metal nanoclusters have attracted enormous attention since discovered. They are found to be novel fluorescence labels for biological applications and environmental monitoring. Recently the chemiluminescence (CL) or electrochemiluminescence (ECL) of metal nanoclusters has received increasing attention. This review covers recent vibrant developments in this field of the past 5 years, and highlights different functions of metal nanoclusters in various CL and ECL systems, such as luminophores, catalysts, and quenchers. Latest synthetic methods of metal nanoclusters used in CL or ECL are also summarized. Furthermore, we discuss some perspectives and critical challenges of this field in the near future. 相似文献
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A nanocomposite of CdSe quantum dots with nitrogen‐doped carbon nanotubes was prepared for enhancing the electrochemiluminescent (ECL) emission of quantum dots. With hydrogen peroxide as co‐reactant, the nanocomposite modified electrode showed a cathodic ECL emission with a starting potential of ?0.97 V (vs. Ag/AgCl) in phosphate buffer solution, which was five‐times stronger than that from pure CdSe quantum dots and three‐times stronger than that from CdSe quantum dots composited with carbon nanotubes. The latter showed a starting potential of ?1.19 V. This result led to a sensitive ECL sensing of hydrogen peroxide with good stability, acceptable reproducibility and a detection limit down to 2.1×10?7 mol L?1. Nitrogen‐doped carbon nanotubes could be used as a good material for the construction of sensitive ECL biosensors for chemical and biochemical analysis. 相似文献
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Due to the highly sensitive electrochemiluminescence (ECL), tris(2,2′-bipyridyl) ruthenium(II) (Ru(bpy)32+) is often used in the field of bioarrays with the help of co-reactants. However, the generally used co-reactant, tripropylamine (TPA), is toxic, corrosive and volatile. Therefore, the search for safe, sensitive and economical co-reactants is critical. Herein, three aminocarboxylic acids, ethylenediamine-tetraacetic acid (EDTA), nitrilotriacetic acid (NTA), and 2-hydroxyethylethylene diaminetriacetic ac... 相似文献
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Dr. Huaping Peng Zhongnan Huang Dr. Haohua Deng Weihua Wu Kaiyuan Huang Zhenglian Li Prof. Wei Chen Prof. Juewen Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(25):10068-10071
Ligand-protected gold nanoclusters (AuNCs) have emerged as a new class of electrochemiluminescence (ECL) luminophores for their interesting catalytic and emission properties, although their quantum yield (ΦECL) in aqueous medium is low with a poor mechanistic understanding of the ECL process. Now it is shown that drying AuNCs on electrodes enabled both enhanced electrochemical excitation by an electrocatalytic effect, and enhanced emission by aggregation-induced ECL (AIECL) for 6-aza-2-thiothymine (ATT) protected AuNCs with triethylamine (TEA) as a coreactant. The dried ATT-AuNCs/TEA system resulted in highly stable visual ECL with a ΦECL of 78 %, and a similar enhancement was also achieved with methionine-capped AuNCs. The drying enabled dual-enhancement mechanism has solved a challenging mechanistic problem for AuNC ECL probes, and can guide further rational design of ECL emitters. 相似文献
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利用巯基乙酸水热法合成出表面修饰—COOH的CdTe量子点,并将CdTe量子点(QDs)连接在Fe3O4纳米粒子表面,制备出CdTe/Fe3O4磁性量子点。通过磁力将磁性量子点修饰于石墨电极表面。在pH7.5的PBS缓冲溶液中,H2O2可使CdTe量子点产生电致化学发光,H2O2浓度在4~100μmol/L范围内与CdTe量子点的电致化学发光强度呈良好的线性关系,检出限为0.24μmol/L。据此建立了测定样品中过氧化氢含量的电致化学发光分析法,并成功地应用于李氏禾草汁原液中过氧化氢含量的测定。该研究借助纳米Fe3O4的磁力特征,使敏感膜易于形成和更新分离,简化了实验操作,同时起到增强发光强度的作用。 相似文献