锌离子荧光探针研究进展

锌广泛存在于人体内,具有重要生理功能。因此,对游离锌离子的选择性识别和有效检测具有重要意义。荧光探针因其设计简单、易于操作、灵敏度高、可细胞成像等诸多优点而广泛应用于锌离子的识别研究。锌离子荧光探针常见的识别机理包括光致电子转移、分子内电荷转移、荧光共振能量转移、聚集诱导荧光增强、螯合荧光增强等。其中,基于螯合荧光增强机理的锌离子探针,其荧光团通常可同时作为识别基团,因此,相比于其它探针,具有设计较为简单、合成较为便捷的优点。本文综述了近年来文献中报道的基于以上各种识别机理的锌离子荧光探针,并着重介绍了螯合荧光增强机理在锌离子识别中的应用。     

基于罗丹明荧光信号报告基团的细胞通透性铜离子荧光探针

分别以罗丹明B和罗丹明6G为荧光信号报告基团,以增强水溶性为目的的羟乙基肼为修饰基团,合成了反应型的Cu_(2+)离子选择性荧光探针分子L1和L2.紫外光谱和荧光光谱等分析结果表明,探针分子L1和L2对Cu_(2+)离子具有高灵敏度、高选择性的光谱识别行为.探针分子对Cu_(2+)离子的识别过程是通过Cu_(2+)离子催化水解控制氧杂蒽荧光信号的螺环酰肼基团实现荧光信号的开启,从而达到识别检测Cu_(2+)离子的目的,对Cu_(2+)离子的检出限均可达到10-8mol/L量级.同时,探针分子对常见金属离子和铵离子均具有较强的抗干扰能力.由于羟乙基肼的引入增强了探针的水溶性,使得探针L1和L2具有良好的细胞通透性和低毒性,实现了其对β-胰岛细胞(INS-1细胞)中Cu_(2+)离子的荧光成像检测.     

喹啉衍生物锌离子荧光传感器*

本文综述了近年来用于锌离子检测的喹啉衍生物荧光传感器的研究进展,介绍了基于喹啉、8-羟基喹啉和8-氨基喹啉合成的锌离子荧光传感器的结构和设计原理,概述了锌离子对喹啉衍生物荧光传感器光学性能的影响,分析了喹啉衍生物锌离子荧光传感器在检测过程中的优点及其实际应用价值,并展望了这类锌离子荧光传感器的研究和发展方向。     

基于T-Hg(Ⅱ)-T结合力和G-四联体非标记型汞离子传感器的研制

利用T-Hg(Ⅱ)-T特异性结合作用识别汞离子(Hg~(2+)),以G-四联体/卟啉类化合物NMM(N-甲基卟啉二丙酸IX)复合结构(G-四联体/NM M)作为荧光信号分子,开发了一种新型汞离子传感器。该传感器操作简单、经济实用且不需要人工修饰化学基团,而且由于G-四联体/NMM的最大发射波长为615 nm,有效避免了生物自发荧光的干扰。研究表明,在对钾离子浓度、NMM浓度等反应条件进行优化后,该传感器对汞离子的检测具有较高的选择性和灵敏性,检出限低至20 nmol/L,与世界卫生组织(WHO)所规定的饮用水中30 nmol/L汞离子标准相当,具有用于检测饮用水中汞离子的潜在实用价值。     

基于胸腺嘧啶碱基错配的汞离子传感器研究进展

基于汞离子和胸腺嘧啶的质子取代反应,可形成T-Hg(Ⅱ)-T碱基错配结构,该结构可作为新型汞离子传感器的良好识别元件。相较于传统汞离子检测方法在效率与精度上的不足,以T-Hg(Ⅱ)-T碱基错配结构为识别基团的新型汞离子传感器具有一定优势。该文综述了以T-Hg(Ⅱ)-T结构为识别基团,以不同类型报告基团为基础的汞离子传感器的研究进展与趋势,从而为后续汞离子传感器的开发提供参考。     

基于T-T碱基错配的荧光传感器特异性检测汞离子

在本文中,我们研制了一种基于T-T碱基错配特异性键合汞离子的荧光传感器用于汞离子的检测。该传感器由两条分别标记了荧光基团（F）和淬灭基团（Q）的DNA探针组成,并且含有两对用于结合汞离子的T-T错配碱基。当汞离子存在时,两条探针之间形成T-Hg2+-T结构,作用力增强,从而拉近了荧光基团与淬灭基团之间的距离,发生能量转移,使荧光信号在一定程度上被淬灭。在优化的条件下,我们使用该传感器对汞离子进行检测,动力学响应范围为50nM到1000nM,线性相关方程为y= 5281.13 - 1650.56 lg[Hg2+] ( R2 = 0.985),检测下限为79nM。此外,我们还考察了该传感器的选择性,当用其它干扰离子（浓度都为1.0µM）代替待测离子进行实验时,没有发生明显的荧光淬灭,说明该传感器具有较高的选择性。该传感器的构建为汞离子的检测提供了一条快速、简便的新途径。     

一种新型铜离子荧光分子探针的合成与性能研究

设计合成了一种新型的以二苯乙烯为荧光团、双(2-吡啶甲基)胺(DPA)为识别基团的铜离子荧光分子探针(E)-4-(4-(双吡啶甲基胺)苯乙烯基)氰基苯(1),其结构用UV,IR,1H NMR,13C NMR和GC/MS进行了表征,并考察了其荧光性能.结果表明该荧光分子探针在CH3CN/H2O(1/9,V/V)溶液中,能...     

具有聚集诱导发光性质的新型二芳基喹喔啉衍生物用于检测Hg~(2+)（英文）

荧光传感器由于具有高灵敏度和高选择性,在检测化学方面得到广泛的应用。本文合成了具有活性荧光团的二芳基喹喔啉衍生物(1～4),并对其进行表征。化合物3同时具有聚集诱导发光(AIE)特征的二芳基喹喔啉、和Hg2+具有特殊反应的1,3-二硫杂环戊二烯-2-硫酮基团,我们将这两个特征基团耦合在同一个化合物之中,从而构建了一类新的"开启"型汞离子荧光传感器。     

光化学传感器的设计、合成及识别性能研究

光化学传感器被广泛地用于检测各种金属离子和阴离子.荧光化学传感器具有选择性好、灵敏度高、简便快速等优点,比色化学传感器则可不借助于任何昂贵的仪器设备而直接用肉眼识别.本论文分别以黄酮﹑香豆素作为发光基团,设计、合成了识别氟离子(F-)和生物巯基化合物(还原性谷胱甘肽和半胱氨酸)的光化学传感器,并研究了其光谱性质和识别机制,另外我们对基于多孔硅的光化学传感器方面进行了一些初步尝试,取得了一些有意义的结果.     

一种基于DPA识别基团的可视化检测锌离子的荧光增强型探针

以N,N-二(2-吡啶甲基)胺(DPA)为识别基团,设计合成了一种用于检测Zn2+的荧光增强型探针WN,在CH3CH2OH/TrisHCl(1∶9,V/V,pH=7.4)缓冲溶液中研究了它对Zn2+的识别特性。实验结果表明,WN对Zn2+有较高的选择性和灵敏度,它们之间的结合比为1∶1,对Zn2+的检出限为1.14×10-8 mol·L-1。WN能够快速地可视化检测Zn2+,在HeLa活细胞中对Zn2+的荧光显微成像表明WN可应用于生物体的检测。     

Unmodified and positively charged gold nanoparticles for sensitive colorimetric detection of folate receptor via terminal protection of small molecule-linked ssDNA

The detection of protein/small molecule interactions plays important roles in drug discovery and protein/metabolite interactions in biology. In this work, by coupling the terminal protection of small molecule-linked ssDNA strategy with the unmodified and positively charged gold nanoparticle ((+)AuNP) nanoprobes, we have developed a sensitive and simple colorimetric sensor for the detection of folate receptor, a highly expressed protein in many kinds of malignant tumors. The target folate receptor binds the folate moieties of the folate-linked ssDNA through high affinity interactions and protects the protein-bound ssDNA from digestion by exonuclease I. The protected ssDNA thus adsorbs the ((+)AuNP) through electrostatic interactions, leading to a red-to-blue color change of the sensing solution for sensitive colorimetric detection of folate receptor at the sub-nanomolar level. Besides, this colorimetric sensor shows high selectivity toward folate receptor against other control proteins. The developed sensor avoids the modification/conjugation of the AuNP nanoprobes and the involvement of any expensive instruments for signal transduction in protein detection. Featured with these obvious advantages, the colorimetric sensor strategy demonstrated herein can be easily expanded for sensitive and convenient detection of various protein/small molecule interactions.     

Facilely constructed two-sided microstructure interfaces between electrodes and cellulose paper active layer: eco-friendly,low-cost and high-performance piezoresistive sensor

Cellulose - The microstructure plays an important role in improving the sensing performance of pressure sensor. However, the design of microstructural active layer of pressure sensor usually...     

用于半胱氨酸检测的电化学生物传感器研究进展

半胱氨酸(Cys)作为人体重要的非必需氨基酸之一,对蛋白质合成、渗透调节、解毒过程、神经系统功能和抗氧化过程均发挥着重要作用,近年来广泛应用于医学临床、食品加工和生化研究领域。因此,发展快速、准确检测半胱氨酸浓度的方法具有重要意义。本文简要介绍了半胱氨酸的基本知识以及半胱氨酸的传统检测方法,对半胱氨酸定量检测的电化学传感器的研制与应用进行了重点阐述,并对其发展前景进行了展望。     

A methionine-based turn-on chemical sensor for selectively monitoring Hg2+ ions in 100% aqueous solution

Dansyl-labeled methionine is synthesized by solid-phase synthesis, and found to be a highly sensitive and selective sensor for Hg(2+). The sensor sensitively detects Hg(2+) ions in aqueous solution by a turn-on response; however, the sensor detects Hg(2+) ions by a turn-off response in organic and mixed aqueous-organic solutions. We investigated the binding stoichiometry, binding constant, and binding mode of the sensor under various solvent conditions. In 100% aqueous solution, 2 : 1 complexation of the sensor with Hg(2+) ions is more favorable than 1 : 1 complexation, whereas the sensor preferentially forms a 1 : 1 complex in 100% CH(3)CN or in 50% CH(3)CN-aqueous solutions. Results reveal that the stoichiometry of the sensor-Hg(2+) complex plays an important role in the type of response to Hg(2+) ions, and that 2 : 1 complexation is required for a turn-on response to Hg(2+) ions in aqueous solution.     

氧化铱纳米颗粒修饰碳纤维电极用于水果中pH在线检测

pH检测在农业生产、食品加工、环境保护、疾病诊断等领域有着重要意义.电化学法具有响应速度快、灵敏度高和操作简单等优点,是目前最常用的pH检测方法之一.然而,商品化的pH计存在体积大、质子敏感膜易损等问题,仅能在相对稳定的样本溶液环境中工作,并不适用于植入式pH分析.本文将氧化铱纳米颗粒修饰在碳纤维微电极表面,构建了一种...     

A Multi‐Component Sensor System for Detection of Amphiphilic Compounds

Many biologically important compounds are amphiphilic in character. Glycolipids, for example, represent a biologically important class of amphiphiles. Receptors and sensors for such compounds must also be amphiphilic making them a challenge to prepare. Here, a cucurbit[8]uril (CB[8])‐based sensor system has been prepared and tested for detection of amphiphilic compounds. This multi‐component system consists: a CB[8], which acts as a hydrophobic lipid receptor, a hydrophilic pyridinium‐based carbohydrate receptor, and a fluorescent indicator. The system self‐assembles in aqueous solution. The pyridinium quenches the fluorescence of the indicator giving a strong turn‐on response when it is displaced by the analyte. The sensor system was characterized by NMR, X‐ray crystallography, and fluorescence titrations.     

Development of a Potentiometric Chemical Sensor for the Rapid Detection of Carbofuran Based on Air Stable Lipid Films with Incorporated Calix[4]arene Phosphoryl Receptor Using Graphene Electrodes

The present article describes a miniaturized potentiometric carbofuran chemical sensor on graphene nanosheets with incorporated lipid films. The graphene electrode was used for the development of a very selective and sensitive chemical sensor for the detection of carbofuran by immobilizing an artificial selective receptor on stabilized lipid films. The artificial receptor was synthesized by transformation of the hydroxyl groups of resorcin[4]arene receptor into phosphoryl groups. This chemical sensor responded for the wide range of carbofuran concentrations with fast response time of ca. 20 s. The presented potentiometric carbofuran chemical sensor is easy to construct and exhibits good reproducibility, reusability, selectivity, rapid response times, long shelf life and high sensitivity of ca. 59 mV/decade over the carbofuran logarithmic concentration range from 10^?6 to 10^?3 M.     

Ratiometric fluorescence and visual sensing of ATP based on gold nanocluster-encapsulated metal-organic framework with a smartphone

Adenosine triphosphate (ATP) plays an important role in various biological processes and the ATP level is closely associated with many diseases. Herein, we designed a novel dual-emissive fluorescence nanoplatform for ATP sensing based on red emissive europium metal-organic framework (Eu-MOF) and blue emissive gold nanoclusters (AuNCs). The presence of ATP causes the decomposition of Eu-MOF owing to strong affinity of Eu³⁺ with ATP. As a result, the red emission of Eu-MOF decreases while the blue emission of AuNCs remains unchanged. The distinct red/blue emission intensity change enables the establishment of a ratiometric fluorescent and visual sensor of ATP. Moreover, a fluorescent paper-based sensor was fabricated with the ratiometric ATP probes, which enabled easy-to-use and visual detection of ATP in serum samples with a smartphone.     

Importance of receptor flexibility in binding of cyclam compounds to the chemokine receptor CXCR4

We have elucidated the binding sites of four moncyclam and one bicyclam antagonist AMD3100, in the human chemokine receptor CXCR4. Using the predicted structural models of CXCR4, we have further predicted the binding sites of these cyclam compounds. We used the computational method LITiCon to map the differences in receptor structure stabilized by the mono and bicyclam compounds. Accounting for the receptor flexibility lead to a single binding mode for the cyclam compounds, that has not been possible previously using a single receptor structural model and fixed receptor docking algorithms. There are several notable differences in the receptor conformations stabilized by monocyclam antagonist compared to a bicylam antagonist. The loading of the Cu(2+) ions in the cyclam compounds, shrinks the size of the cyclam rings and the residue D262(6.58) plays an important role in bonding to the copper ion in the monocylam compounds while residue E288(7.39) is important for the bicyclam compound.     

Incubation type Si-based planar ion channel biosensor

A new planar-type ion channel biosensor with the function of cell culture has been fabricated using silicon on an insulator substrate as the sensor chip material. Coating of the sensor chip with fibronectin was essentially important for cell incubation on the chip. Although the seal resistance was quite low (∼7 MΩ) compared with the pipette patch-clamp gigaohm seal, the whole-cell channel current of the transient receptor potential vanilloid type 1 (TRPV1) channel expressing HEK293 cells was successfully observed, with a good signal-to-noise ratio, using capsaicin as a ligand molecule. Figure A new planer type ion channel biosensor with function of cell culture is fabricated using the silicon on insulator substrate as the sensor chip material. The coating of the sensor chip by the fibronectin was essentially important for the cell incubation on the chip. Whole cell channel current of TRPV1 channel was successfully observed using capsaicin as a ligand molecule with good signal to noise.