基于聚合物点的电致化学发光生物传感器用于葡萄糖检测

羧基功能化的聚[(9,9-二辛基芴基-2,7-二基)-co-(1,4-苯并-{2,1′,3}-噻二唑)]聚合物点(PFBT-COOH)在无外加共反应试剂的条件下具有高的电致化学发光(ECL)信号,且过氧化氢(H_2O_2)对其ECL具有高效猝灭作用。采用PFBT-COOH修饰玻碳电极,进一步交联葡萄糖氧化酶(GOD)以构建酶传感器(GOD/PFBT-COOH/GCE)。随着检测底液中葡萄糖浓度的增加,葡萄糖在GOD催化下原位产生的H_2O_2量增加,导致传感器的ECL信号逐渐减弱,从而实现葡萄糖的准确、快速、灵敏检测。此方法测得葡萄糖的线性范围为1.0×10~(-7)～3.0×10~(-3) mol/L,检出限为3.0×10~(-8) mol/L。血清样品中葡萄糖的加标回收率为98.5%～106%。该策略为酶传感器的构建提供了新思路,为葡萄糖的检测提供了新方法。     

Tris（2,2＇-bipyridyl） Ruthenium（Ⅱ） Doped Silica Film Modified Indium Tin Oxide Electrode and Its Electrochemiluminescent Properties

An approach was reported to synthesize silica hybridized ruthenium bipyridyl complex through amidation reaction by covalent attachment of bis（bipyridyl）-4,4＇-dicarboxy-2,2＇-bipyridyl-ruthenium to （3-aminopropyl）-triethoxysilane. The hybrid complex then was gelatinized through acid catalytic hydrolysis method and a sol-gel modified indium tin oxide electrode was prepared via spin coating technique. As prepared indium tin oxide electrode possesses good stability therein with excellent electrochemiluminescence behavior.     

A Novel Solid‐state Electrochemiluminescent Enantioselective Sensor for Ascorbic Acid and Isoascorbic Acid

A novel, stable, solid‐state and stereoselective electrochemiluminescence (ECL) sensor has been designed to enantioselectively discriminate ascorbic acid (AA) and isoascorbic acid (IAA) by immobilizing Ru(bpy)₃²⁺ (Ru), thiolated β‐cyclodextrin (β‐CD‐SH) and gold/platinum hybrid nanoparticles supported on multiwalled carbon nanotube/silica coaxial nanocables (GP‐CSCN) on glassy carbon electrode. All chemical compounds could be immobilized on the surface of electrode stably through nafion film, and high stereoselectivity could be introduced to the sensor via the synergistic effects of the β‐CD‐SH and GP‐CSCN nanomaterials. When the developed sensor interacted with AA and IAA, obvious difference of ECL intensities was observed, and a larger intensity was obtained from AA, which indicated that this strategy could be employed to enantioselectively recognize AA and IAA. As a result, ECL technique might act as a promising method for recognition of chiral compounds.     

Molecular Size and Electronic Structure Combined Effects on the Electrogenerated Chemiluminescence of Sulfurated Pyrene‐Cored Dendrimers

The electrochemistry, photophysics, and electrochemically generated chemiluminescence (ECL) of a family of polysulfurated dendrimers with a pyrene core have been thoroughly investigated and complemented by theoretical calculations. The redox and luminescence properties of dendrimers are dependent on the generation number. From low to higher generation it is both easier to reduce and oxidize them and the emission efficiency increases along the family, with respect to the polysulfurated pyrene core. The analysis of such data evidences that the formation of the singlet excited state by cation–anion annihilation is an energy‐deficient process and, thus, the ECL has been justified through the triplet–triplet annihilation pathway. The study of the dynamics of the ECL emission was achieved both experimentally and theoretically by molecular mechanics and quantum chemical calculations. It has allowed rationalization of a possible mechanism and the experimental dependence of the transient ECL on the dendrimer generation. The theoretically calculated Marcus electron‐transfer rate constant compares very well with that obtained by the finite element simulation of the whole ECL mechanism. This highlights the role played by the thioether dendrons in modulating the redox and photophysical properties, responsible for the occurrence and dynamics of the electron transfer involved in the ECL. Thus, the combination of experimental and computational results allows understanding of the dendrimer size dependence of the ECL transient signal as a result of factors affecting the annihilation electron transfer.     

直接进样电喷雾离子阱质谱法对含硫三联吡啶衍生物的研究

采用电喷雾电离质谱通过直接进样方式对合成的3个含硫的三联吡啶配体及2个钌配合物进行分析,详细研究了其在电喷雾条件下的质谱行为。结果表明,含有芳硫基和苄硫基的三联吡啶配体在电喷雾过程中采取了不同的断裂方式,前者首先从与芳硫键相连的碳硫键断裂失去不含硫的部分碎片离子,而后者则从苄基碳硫键断裂失去含硫的部分碎片离子。两类配体与钌形成的配合物均具有较稳定的结构,不易发生多级质谱断裂。通过对配合物分子离子峰和同位素峰的分析讨论,确定了含硫的三联吡啶合钌配合物的结构。这一研究结果表明电喷雾多级串联质谱适合于含硫三联吡啶类配体及其钌配合物的结构研究,方法简便高效、准确可靠,为该类化合物的结构研究提供了参考。     

构建新型固相电致化学发光传感界面用于检测三丙胺

通过静电作用将带正电的Ru(bpy)23+和带负电的纳米铂制备成铂钌纳米复合物(Ru-PtNPs),并将其滴涂在Nafion分散的多壁碳纳米管(MWCNTs-Nafion)复合膜修饰的玻碳电极上,制备了一种新的基于联吡啶钌的固相电致化学发光(ECL)传感器。利用扫描电镜以及电致化学发光的方法对传感界面进行表征。实验结果表明,通过此种方式可将大量的发光试剂Ru(bpy)23+固载到电极表面,并对三丙胺(TPA)保持良好的电催化活性,Ru-PtNPs/MWCNTs-Nafion修饰电极在0.1 mol.L-1磷酸盐缓冲溶液(PBS,pH 7.4)中对TPA的响应有很好的灵敏度和稳定性,线性范围为6.67×10-7～1.00×10-3mol·L-1,检出限(S/N=3)为3.3×10-7 mol·L-1。     

Electrochemiluminescence Single-cell Analysis on Nanostructured Interface

Due to the heterogeneity of single cells, the development of single-cell analysis methods is conducive to the research of cellular mechanisms, clinical diagnosis, and treatment. Electrochemiluminescence (ECL) has the advantage of being controllable in time and space. Compared with spectroscopy, ECL does not require a light source, thus avoiding the interference of scattered light and luminescent impurities. Therefore, ECL is playing an increasingly important role in the field of single-cell analysis. In ECL single-cell analysis, it is important to construct a suitable nanostructure interface to realize signal conversion. This review first briefly introduced the ECL system commonly used in single-cell analysis, then focused on the recent developments in ECL single-cell analysis on nanostructure interface, finally discussed the future challenges and outlooks of ECL single-cell analysis.     

CdS纳米晶@碳点复合物膜的电致化学发光

采用热解柠檬酸法制备碳点(CDs),并将之与表面无包裹剂的CdS纳米晶(CdS NCs)超声复合制备CdS纳米晶@碳点(CdS NCs@CDs)复合物。研究了复合物膜阴极电致化学发光(ECL),探讨了CDs对CdS纳米晶膜ECL增强的机理。CDs分散性良好、尺寸在1.5~4 nm之间;与粒径约为4 nm的CdS纳米晶按体积比2∶3复合后,在360 nm光激发下复合物具有最强的荧光发射且表现为CDs的荧光。同时,复合物膜产生归属于激发态CdS纳米晶的最强的ECL发射,且ECL发光峰起置电势正移至-1.05 V。复合物膜的ECL发射是pH依赖的,在pH值为6时,复合物膜具有最大的ECL强度,为CdS纳米晶膜ECL强度的19倍。这种ECL增强源于CDs能束缚大量电子产生局域电场从而促进近邻CdS纳米晶激发态的形成与弛豫。     

基于电化学发光和阻抗技术研究DNA单碱基错配

单碱基错配的识别和稳定性差异在核酸多态性研究中至关重要。在同一电化学传感器平台上,采用电化学发光（ECL）和电化学阻抗（EIS）2种技术,协同研究DNA链中不同类型和不同位点的单碱基错配识别和稳定性差异。电极表面具有茎环构象的探针DNA与完全互补DNA、不同类型或不同位点单碱基错配DNA杂交前后的ECL和EIS信号强度变化有显著差异。信号强度变化可揭示单碱基错配识别的稳定性。结果表明,DNA链中心位点的C-A单碱基错配稳定性低于链两端的,靠近键合电极表面双链链端的C-A单碱基错配稳定性低于非键合电极表面双链链端的,同一中心位点C-X碱基对的稳定性顺序为C-G?C-T>C-A≥C-C。研究结果可为核酸多态性研究提供参考。