基于量子点的电化学发光核酸分析传感器研究进展

核酸是一种十分重要的生物大分子,有关核酸分析的研究一直是生物分析中非常活跃的领域。电化学发光(ECL)技术具备灵敏度高、可控性强、选择性高等优点,广泛应用于生物分析领域。量子点(QDs)具有优异的光学特性和良好的电化学性能。量子点独特的光电特性可与电化学发光相结合,构建灵敏度高、特异性强及检出限低的电化学发光生物传感器用于核酸分析。本文简要地介绍了量子点并对其进行系统的分类,重点介绍了量子点作为发光体材料在电化学发光核酸分析传感器中的应用。     

铅卤钙钛矿纳米晶的电致化学发光

卤化铅钙钛矿纳米晶体(Lead halide perovskites nanocrystals,LHP NCs)具有高摩尔吸光度系数、晶格缺陷高容忍度、超高载流子迁移率和窄发射半峰宽等优良特性,其研究在光伏和光电子领域得到了广泛的重视,而LHP NCs优良的光电特性也使之在分析传感领域受到关注。近年来,国内外相继发表了多篇综述文章,包括LHP NCs的合成、提高LHP NCs材料稳定性的方法及其在太阳能电池、LED、激光、光催化等方面的应用。然而,目前LHP NCs在传感领域,特别在电致化学发光(Electrochemiluminescence,ECL)方面的研究和应用,还缺乏比较系统的综述。该文综述了LHP NCs的ECL研究及其应用情况,讨论了LHP NCs ECL相关研究中存在的问题和面临的挑战,以期增加读者对LHP NCs ECL研究现状和未来发展趋势的了解。     

大尺寸石墨烯量子点组装体的制备及电化学发光性能

对氧化石墨烯纳米材料进行HNO₃氧化处理, 制备了水溶性好且具有强电化学发光(ECL)活性的大尺寸石墨烯量子点组装体(Large-sized graphene quantum dot assemblies, LSGQD-NAs). 利用透射电子显微镜(TEM)、 原子力显微镜(AFM)、 傅里叶变换红外光谱(FTIR)和拉曼光谱(Raman)等方法对其进行了表征, 结果表明, 石墨烯量子点组装体的平均高度为20 nm, 且富含大量的羟基和羧基. 电化学测试结果显示, 在共反应物K₂S₂O₈存在下, LSGQD-NAs在阴极产生很强的ECL(峰值约在685 nm); 并推测了其ECL反应机理, 发现LSGQD-NAs容易通过中心未氧化的石墨烯π-π作用于GC电极表面进行组装修饰. 本研究为基于石墨烯量子点ECL传感器的研究提供了新方法.     

南京大学鞠熀先研究组近期的研究成果介绍

量子点的电致化学发光(ECL)技术集成了发光分析的高灵敏度和电化学分析的电位可控性的优点,已成为分析化学工作者十分感兴趣的研究领域之一。最近,南京大学生命分析化学教育部重点实验室鞠熀先研究组对量子点的阴极和阳极ECL性质进行了深入地研究,探讨了发光机理,并成功地将其应用于生物分析和实际样品的检测。图1裸电极和QDs膜修饰石墨充蜡电极在氧气饱和的磷酸缓冲溶液(pH7.0)中的循环伏安(a,b)和ECL(c,d)曲线该研究组于2004年提出第一支量子点水相电致化学发光传感器,并用于H2O2检测(Anal.Chem.2004,76:6871~6876)。通过构建仿生…     

硅量子点为共反应剂的联吡啶钌电致化学发光研究及对多巴胺的检测

利用水热法合成了水溶性硅量子点(SiQDs),并探究了联呲啶钌(Ru(bpy)■)在硅量子点修饰玻碳电极(SiQDs/GCE)上的电致化学发光(ECL)行为。结果表明,在中性条件下,SiQDs能够作为共反应剂明显增强Ru(bpy)■的阳极ECL信号。研究了SiQDs修饰量、缓冲溶液pH等因素对该体系ECL信号的影响规律,并对ECL机理进行了探讨。多巴胺对ECL信号具有明显的抑制作用,据此可以实现对多巴胺的灵敏检测。在1.0×10~(-8)～1.0×10~(-4) mol·L~(-1)范围内,多巴胺浓度与ECL信号的减少值呈线性变化关系,相关系数达0.993。     

基于碳点的发光材料在潜在手印显现中的应用

遗留在犯罪现场的肉眼不可见的潜在手印是一类重要的痕迹物证,检验鉴定前需要使用一定技术手段将其显现出来。近年来,一些新材料和新技术的引入为手印显现技术的革新注入了新活力,其中稀土发光材料、量子点、荧光金属纳米簇等发光材料在该领域展现出极大潜力。碳点作为具有良好光致发光性能的新型纳米材料,近来逐渐引起了手印显现领域研究人员的广泛关注。本文综述了两类基于碳点材料的手印显现技术国内外研究进展,分别是液体分散碳点用于手印显现和固态发光碳点用于手印显现。具体来说,液体分散碳点显现手印的原理主要基于传统小微粒悬浮液机理或一些特殊效应(咖啡环效应、界面偏析效应);用于手印显现的固态发光碳点包括固态碳点粉末和固态碳点复合粉末两类,合成这些材料时研究人员采用了不同的策略。最后,从三个方面分析了碳点在手印显现应用中面临的问题,即碳点物理形貌和表面性质、碳点光致发光性质以及碳点显现过程与化学生物分析兼容性,并就解决问题的可能途径提出了展望。     

硫化镉量子点对三联吡啶钌电化学发光的增敏作用及用于邻苯二酚的检测

研究了CdS量子点(CdS QDs)对三联吡啶钌(Ru(bpy)_3~(2+))电致化学发光(ECL)信号的作用,发现CdS QDs对Ru(bpy)_3~(2+)的ECL信号有良好的增敏作用,基于此建立了高灵敏的CdS QDs/Ru(bpy)_3~(2+)ECL体系。探讨了该体系的ECL机理,考察了CdS QDs的浓度、缓冲溶液p H值、扫描速率等实验参数对ECL信号的影响,优化了体系的ECL条件。基于邻苯二酚对该体系ECL信号的抑制作用,建立了邻苯二酚的ECL检测方法。在1.0×10~(-8)~1.0×10~(-5)mol/L范围内,邻苯二酚的浓度与ECL信号的变化值呈良好的线性关系,检出限(S/N=3)为5.5 nmol/L,将本方法用于茶叶中邻苯二酚的检测,结果令人满意。     

超四面体硫簇结构调控与电化学发光研究进展

电化学发光(ECL)因其独特的性能特点在生物分析等领域展现出广阔的应用前景,高效ECL试剂的开发则为性能优异的传感器件的发展和临床应用提供了重要工具. 开放骨架超四面体硫簇由于同时具有分子筛的多孔结构和半导体的优异光电性能,在ECL分析中受到了越来越多的关注. 超四面体硫簇的结构组成可以实现原子级别的精确调控,并且其本身还可以作为结构单元来构筑多孔结构半导体材料. 这些特点使通过原子级别的结构组成调节来调控超四面体硫簇的性能成为可能,为发展性能优异的电化学发光材料,拓展其在生化传感、免疫分析和生物成像等方面的应用提供有效工具. 本综述总结了超四面体硫簇的合成、缺陷掺杂、功能调控及ECL生化分析等方面的研究进展,为推进高效ECL新材料的发展和新应用的拓展提供了借鉴.     

单个量子点的光学性质与应用

量子点(QDs)是一种具有诸多优良光学特性的荧光纳米颗粒,已在化学分析、生物传感、分子影像等领域得到了广泛应用.单个量子点的光学性质研究有望发现一些宏观方法不能发现的实验现象,可以为改善其光学性能提供思路,有助于更好的应用于各领域.本文评述了单个量子点的检测与判定方法,单个量子点的荧光增强、漂白、眨眼(blinking)、蓝移等光学性质及其在单分子示踪、生物化学传感、超分辨定位技术等方面的应用.总结了目前量子点作为荧光探针在实际应用中遇到的问题,并提出未来量子点将朝着合成能同时满足尺寸小、量子产率高、 "non-blinking"、蓝移幅度大、无生物毒性的量子点及能同时为成像/检测提供荧光探针与散射探针的等离子体量子点等研究方向发展.     

CdTe量子点修布电极的阳极电致化学发光

制备了CdTe量子点/Nafion修饰玻碳电极(CdTe QDs/Nafion/GCE),并研究了该修饰电极在中性磷酸盐缓冲溶液(PBS)中的电致化学发光(ECL)行为.结果表明,三丙胺(TPA)作为共反应剂存在时,QDs/Nafion/GCE在中性PBS中可以产生强的阳极电化学发光信号.考察了量子点的用量、Nafion的用量、pH、电解质等条件对ECL的影响.抗坏血酸对QDs/Nafion/GCE的ECL具有抑制作用,且抑制程度与抗坏血酸浓度呈线性关系,为利用电致化学发光法检测抗坏血酸提供了新方法.     

Strategies of tailored nanomaterials for electrochemiluminescence signal enhancements

Nanomaterials and their applications were studied extensively over the past few decades due to their properties which are associated mainly with the nanoscale sizes and unique characteristics that they have. Among many applications, these nanomaterials have been playing great, multifaceted roles in increasing the analytical performances of electrochemiluminescence (ECL). In this article, we review the main possible approaches – based on nanoparticles – to modify the photophysical properties of the excited state generated as a consequence of the electrochemical stimulus and in particular taking profit of the so-called metal-enhanced fluorescence (MEF) and resonance energy transfer (RET) processes. We believe that these strategies will lead to the design of very efficient systems that can substantially increase the possible successful applications of ECL.     

Highly fluorescent N,N-dimethylaminophenylethynylarenes: synthesis, photophysical properties, and electrochemiluminescence

A new family of aryl-pi-donor-aryl molecules has been synthesized and studied with respect to their photophysical properties and electrogenerated chemiluminscence (ECL) for the first time. Anthracene, phenanthrene, naphthalene, biphenyl, and fluorene were coupled with N,N-dimethylanilino moiety via a C-C triple bond (1-7). Introduction of such a strong electron-donating moiety as N,N-dimethylanilino group through a triple bond imparts new properties to the resultant molecules that are not commonly observed for the parent arenes. All molecules show absorption in the near-visible region and emission totally in the visible region with high fluorescence quantum yields. Bright solid-state photoluminescence has also been noticed for all the compounds in the visible region. 9-Anthryl- and 1-naphthyl- derivatives exhibited blue-shifted electrochemiluminescence (ECL) relative to their photoluminescence because of aggregation. 9-Phenanthryl- and 2-naphthyl- derivatives did not show ECL. 2-Biphenyl derivative showed monomeric ECL while 4-biphenyl counterpart exhibited excimer ECL. No ECL was observed for 2-fluorenyl derivative. The observed electronic properties are discussed with regard to the structure of the molecules. The characteristics of the molecules chosen in the present study open up new prospects and promises for novel tunable organic materials, on the basis of simple extension of conjugation to promote intramolecular communication, for ECL, OLED, and other optoelectronic applications.     

多孔金属有机膦酸化合物的制备

本文概述了制备多孔金属有机膦酸化合物的三种途径,即直接反应法,引入第二配体法和引入模板剂的方法,并对多孔金属无机膦酸材料的潜在用途作了简单介绍。     

含金属笼型倍半硅氧烷的研究进展

倍半硅氧烷作为催化剂载体硅胶表面结构与性能研究的模型,可以通过表征其表面反应性质来直观认识硅胶负载型催化剂的作用机制。过去几十年来,倍半硅氧烷的研究呈现飞跃式的发展态势,开发出许多新化合物和新合成方法,并在一些催化过程中得到应用。将倍半硅氧烷作为金属化合物的配体,极大地丰富了元素化学的内容。本文重点介绍了合成含金属笼型倍半硅氧烷的相关进展,同时介绍了含金属笼型倍半硅氧烷在聚合物材料应用中的研究。     

Electroactive Metal–Organic Frameworks as Emitters for Self-Enhanced Electrochemiluminescence in Aqueous Medium

Metal–organic frameworks (MOFs) have limited applications in electrochemistry owing to their poor conductivity. Now, an electroactive MOF (E-MOF) is designed as a highly crystallized electrochemiluminescence (ECL) emitter in aqueous medium. The E-MOF contains mixed ligands of hydroquinone and phenanthroline as oxidative and reductive couples, respectively. E-MOFs demonstrate excellent performance with surface state model in both co-reactant and annihilation ECL in aqueous medium. Compared with the individual components, E-MOFs significantly improve the ECL emission due to the framework structure. The self-enhanced ECL emission with high stability is realized by the accumulation of MOF cation radicals via pre-reduction electrolysis. The self-enhanced mechanism is theoretically identified by DFT. The mixed-ligand E-MOFs provide a proof of concept using molecular crystalline materials as new ECL emitters for fundamental mechanism studies.     

Electroactive Metal–Organic Frameworks as Emitters for Self‐Enhanced Electrochemiluminescence in Aqueous Medium

Metal–organic frameworks (MOFs) have limited applications in electrochemistry owing to their poor conductivity. Now, an electroactive MOF (E‐MOF) is designed as a highly crystallized electrochemiluminescence (ECL) emitter in aqueous medium. The E‐MOF contains mixed ligands of hydroquinone and phenanthroline as oxidative and reductive couples, respectively. E‐MOFs demonstrate excellent performance with surface state model in both co‐reactant and annihilation ECL in aqueous medium. Compared with the individual components, E‐MOFs significantly improve the ECL emission due to the framework structure. The self‐enhanced ECL emission with high stability is realized by the accumulation of MOF cation radicals via pre‐reduction electrolysis. The self‐enhanced mechanism is theoretically identified by DFT. The mixed‐ligand E‐MOFs provide a proof of concept using molecular crystalline materials as new ECL emitters for fundamental mechanism studies.     

Analytical applications of nanomaterials in electrogenerated chemiluminescence

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.     

Fundamentals and bioanalytical applications of functional quantum dots as electrogenerated emitters of chemiluminescence

Since the electrochemiluminescence (ECL) of quantum dots (QDs) of silicon was reported by Science in 2002, lots of QDs (e.g., II-VI, III-V and IV-VI) with different sizes and shapes have been used as ECL emitters for bioanalysis. Especially, QDs functionalized with multitudinous biomolecules offer excellent ECL signal-transduction platforms for designing a new generation of biosensing devices.In this article, we focus on recent advances in the ECL principles of functional QDs, and their bioanalytical applications in DNA analysis, immunoassay, cytosensing and detection of other biological molecules.     

Recent Advances in Aggregation-Induced Electrochemiluminescence

The emergence of the rising alliance between aggregation-induced emission (AIE) and electrochemiluminescence (ECL) is defined as aggregation-induced electrochemiluminescence (AIECL). The booming science of AIE has proved to be not only distinguished in luminescent materials but could also inject new possibility into ECL analysis. Especially in the aqueous phase and solid state for hydrophobic materials, AIE helps ECL circumvent the dilemma between substantial emission intensity and biocompatible media. The wide range of analytes makes ECL an overwhelmingly interesting analytical technique. Therefore, AIECL has gained potential in clinical diagnostics, environmental assays, and biomarker detections. This review will focus on introduction of the novel concept of AIECL, current applied luminophores, and related applications developed in recent years.