排序方式: 共有81条查询结果,搜索用时 31 毫秒
1.
Anxun Zheng Chang Shen Prof. Qian Tang Dr. Cheng-Bin Gong Dr. Cheuk-Fai Chow 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(41):9643-9649
Herein, a catalytic chemosensing assay (CCA), based on a bimetallic complex, [RuII(bpy)2(CN)2]2(CuII)2 (bpy=2,2′-bipyridine), is described. This complex integrates a task-specific catalyst (CuI-catalyst) and a signaling unit ([RuII(bpy)2(CN)2]) to specifically hydrolyze methyl parathion, a highly toxic organophosphate (OP) pesticide. The bimetallic complex catalyzed the hydrolysis of the phosphate ester to generate o,o-dimethyl thiophosphate (DTP) anion and 4-nitrophenolate. Intrinsically, 4-nitrophenolate absorbed UV/Vis light at λmax=400 nm, creating the first level of the chemosensing signal. DTP interacted with the original complex to displace the chromophore, [RuII(bpy)2(CN)2], which was monitored by spectrofluorometry; this was classified as the second level of chemosensing signal. By integrating both spectroscopic and spectrofluorometric signals with a simple AND logic gate, only methyl parathion was able to provide a positive response. Other aromatic and aliphatic OP pesticides (diazinon, fenthion, meviphos, terbufos, and phosalone) and 4-nitrophenyl acetate provided negative responses. Furthermore, owing to the metal-catalyzed hydrolysis of methyl parathion, the CCA system led to the detoxification of the pesticide. The CCA system also demonstrated its catalytic chemosensing properties in the detection of methyl parathion in real samples, including tap water, river water, and underground water. 相似文献
2.
Dr. Daniele Paderni Dr. Eleonora Macedi Dr. Larisa Lvova Dr. Gianluca Ambrosi Prof. Mauro Formica Prof. Luca Giorgi Prof. Roberto Paolesse Prof. Vieri Fusi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(49):e202201062
A new series of ligands containing the 2-(2-hydroxy-3- naphthyl)-4-methylbenzoxazole (HNBO) fluorophore showed selectivity for Mg2+ ions, without the interference of Ca2+. The most promising representative L3 resulted the best performing sensor for Mg2+ both in solution and embedded in an all-solid-state optode, especially towards real samples of drinkable water. 相似文献
3.
The absorption and fluorescence spectroscopic responses of three pyridinium hemicyanine dyes to anions F−, Cl−, Br−, I−, H2PO4−, HSO4− and OAc− were investigated. At lower concentrations of OAc− (less than 1 equiv.), both the absorption and the fluorescence intensities of 1 – 3 were more effectively changed than F− at identical concentrations. At higher concentrations of OAc− (more than 1 equiv.), the interaction was opposite for each compound. 1H NMR results indicated the interaction between 1 , 2 or 3 and F− proceeded through hydrogen bonding. The results showed that these dyes are promising to develop dual fluorescence and chromogenic chemosensors toward F− and OAc− according to the subtle difference in the affinity of F− and OAc−. 相似文献
4.
Fasil A. AbebeEkkehard Sinn 《Tetrahedron letters》2011,52(41):5234-5237
Two new fluorescein-based chemosensors for Cu2+ were designed with highly selective “off-on” behavior, one of them working in both absorption and emission, the other only in absorption. Binding to Cu2+ binding is reversible, as indicated by the bleaching of the color when the metal is extracted. The compounds form the basis for rapid, selective and sensitive Cu2+ chemosensors in aqueous media. 相似文献
5.
A novel turn-on rhodamine B-based fluorescent chemosensor (RBCS) was designed and synthesized by reacting N-(rhodamine B)lactam-1,2-ethylenediamine and carbon disulfide. Upon addition of Fe3+ in EtOH/H2O solution (2:1, v/v, HEPES buffer, 0.6?mM, pH 7.20), the RBCS displayed a significant fluorescence enhancement at 582?nm and a dramatic color change from colorless to pink, which can be detected by the naked eye. Significantly, the RBCS exhibited a highly selective and sensitive ability toward Fe3+. The detection limit of the probe was 2.05?×?10?7?M. Job's plot indicated the formation of 1:1 complex between the RBCS and Fe3+. Moreover, the practical use of the RBCS is demonstrated by its application in the detection of Fe3+ in HeLa cells. 相似文献
6.
荧光分子在良溶剂中基本不发光或发光较弱,而在聚集状态下发光较强的现象,称为聚集诱导发光(Aggregation-induced emission,AIE)现象,这与传统的聚集导致猝灭(Aggregation-caused quenching,ACQ)现象相反。本文研究了多苯基吡咯衍生物的结构与发光性能的关系。通过比较吡咯衍生物的单晶结构和发光性质发现扭曲的结构可以限制共轭发光基团的分子内旋转(RIR),这是产生AIE现象的主要原因。羧酸化的吡咯衍生物可以对Al3+实时、选择性检测。由DMF诱导的三苯基吡咯羧酸衍生物(TPPA)重结晶在固态时出现可控的荧光发射,它具备很好的温度选择性,响应迅速,并可以循环利用,这证明TPPA可以作为一种热响应材料用于温度监控设备中。 相似文献
7.
双光子荧光显微成像兼具诸如近红外激发、暗场成像、避免荧光漂白和光致毒、定靶激发、高横向分辨率与纵向分辨率、降低生物组织吸光系数及降低组织自发荧光干扰等特点而显著地优于单光子荧光显微成像,为生命科学研究提供了更为锐利的工具。而用于像离子的含量及其对生理的影响、离子参与的生理活动机制、离子与分子的作用、特定分子的分布及其相互作用等方面研究的双光子荧光探针,是实现成像的关键。双光子荧光探针的研究旨在促进双光子荧光显微镜应用的发展,促进生命科学、医学科学的快速发展,同时也带动双光子荧光探针所隶属的化学这一学科的发展。因此对双光子荧光探针的研究具有重要的理论和实践意义。该文综述了双光子荧光显微成像的优点、双光子荧光探针设计的原理及双光子荧光探针在离子分析方面的应用,并展望了这类荧光探针的发展趋势与应用前景。 相似文献
8.
A Highly Selective and Sensitive Turn-On Fluorescent Chemosensor Based on Rhodamine 6G for Iron(III)
Zhi-Qiang Hu Ying-Ying Gu Wen-Zhou Hu Lei-Li Sun Jiang-Hua Zhu Yi Jiang 《ChemistryOpen》2014,3(6):264-268
Recently, more and more rhodamine derivatives have been used as fluorophores to construct sensors due to their excellent spectroscopic properties. A rhodamine-based fluorescent and colorimetric Fe3+ chemosensor 3’,6’-bis(ethylamino)-2-acetoxyl-2’,7’-dimethyl-spiro[1H-isoindole-1,9’-[9H]xanthen]-3(2H)-one (RAE) was designed and synthesized. Upon the addition of Fe3+, the dramatic enhancement of both fluorescence and absorbance intensity, as well as the color change of the solution, could be observed. The detection limit of RAE for Fe3+ was around 7.98 ppb. Common coexistent metal ions showed little or no interference in the detection of Fe3+. Moreover, the addition of CN− could quench the fluorescence of the acetonitrile solution of RAE and Fe3+, indicating the regeneration of the chemosensor RAE. The robust nature of the sensor was shown by the detection of Fe3+ even after repeated rounds of quenching. As iron is a ubiquitous metal in cells and plays vital roles in many biological processes, this chemosensor could be developed to have applications in biological studies. 相似文献
9.
A novel copolymer, poly(N‐hexyl‐3,7‐phenothiazylene‐1,2‐ethenylene‐2,6‐pyridylene‐1,2‐ethenylene) ( P3 ), containing N‐hexyl‐3,7‐phenothiazylene and 2,6‐pyridylene chromophores was synthesized to investigate the effect of protonation, metal complexation, and chemical oxidation on its absorption and photoluminescence (PL). Poly(N‐hexyl‐3,8‐iminodibenzyl‐1,2‐ethenylene‐1,3‐phenylene‐1,2‐ethenylene) and poly(N‐hexyl‐3,7‐phenothiazylene‐1,2‐ethenylene‐1,3‐phenylene‐1,2‐ethenylene) ( P2 ), consisting of 1,3‐divinylbenzene alternated with N‐hexyl‐3,8‐iminodibenzyl and N‐hexyl‐3,7‐phenothiazylene, respectively, were also prepared for comparison. Electrochemical investigations revealed that P3 exhibited lower band gaps (2.34 eV) due to alternating donor and acceptor conjugated units (push–pull structure). The absorption and PL spectral variations of P3 were easily manipulated by protonation, metal chelation, and chemical oxidation. P3 displayed significant bathochromic shifts when protonated with trifluoroacetic acid in chloroform. The complexation of P3 with Fe3+ led to a significant absorption change and fluorescence quenching, and this implied the coordination of ferric ions with the 2,6‐pyridylene groups in the backbone. Moreover, both phenothiazylene‐containing P2 and P3 showed conspicuous PL quenching with a slight redshift when oxidized with NOBF4. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1272–1284, 2004 相似文献
10.
Colorimetric detection of anions (HSO4? and CN?) was achieved via analyte triggered colour changing of the dipodal and tripodal sensors in CH3CN–H2O (1:1). The sensors exhibited very sharp visual colour changes and fluorescence quenching–enhancing effect upon addition of the HSO4? and CN?. The large downfield shift of the NH proton signals in 1H-NMR complexation studies and quantum chemical DFT calculations proved the formation of hydrogen-bonded complexes where no proton transfer mechanism was found. 相似文献