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1.
《Journal of Coordination Chemistry》2012,65(19):3383-3394
This article describes an electrochemical metal-ion sensor based on a cobalt phthalocyanine (CoPc) complex and determination of its sensor activity for some transition metal ions. Ag+ and Hg2+, among several transition metal ions, coordinate to the sulfur donors of CoPc and alter the electrochemical responses of CoPc in solution, indicating possible application of the complex as Ag+ and Hg2+ sensor. For practical application, CoPc was encapsulated into a polymeric cation exchange membrane, Nafion, on a glassy carbon electrode and used as an electrochemical coordination element. This composite electrode was potentiometrically optimized and potentiometrically and amperometrically characterized as transition metal-ion sensors with respect to reproducibility, repeatability, stability, selectivity, linear concentration range, and sensitivity. A µmol?dm?3 sensitivity of the CoPc-based sensor indicates its possible practical application for the determination of Ag+ and Hg+2 in waste water samples. 相似文献
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Saluma Samanman Apon Numnuam Warakorn Limbut Proespichaya Kanatharana Panote Thavarungkul 《Analytica chimica acta》2015
For the first time, a simple and highly sensitive label-free electrochemical carcinoembryonic antigen (CEA) immunosensor based on a cryogel electrode has been developed and tested. The as-prepared nanocomposite combined the advantages of the graphene, AuNPs and chitosan (AuNPs–GP–CS) together with the ease of preparing a cryogel coupled to a silver deposition, to act as a redox mediator, on a Au electrode. Under the optimal conditions, the decrease of the cyclic voltammetry (CV) silver peak current was proportional to the CEA concentration over a range of from 1.0 × 10−6 to 1.0 ng mL−1 with a detection limit of 2.0 × 10−7 ng mL−1. This AuNPs–GP–CS cryogel electrode gave a 1.7 times higher sensitivity and 25 times lower detection limit than the non-cryogel electrode. Moreover, the proposed electrochemical immunosensor exhibited good selectivity, reproducibility and stability. When applied to analyse clinical serum samples, the data determined by the developed immunosensor were in agreement with those obtained by the current hospital analysis system (enzyme linked fluorescent assay) (P > 0.05), to indicate that the immunosensor would be potentially useful for clinical diagnostics. 相似文献
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M. R. Ganjali Tahereh Poursaberi Fatemeh Basiripour Masoud Salavati-Niassari Mohammad Yousefi Mojtaba Shamsipur 《Analytical and bioanalytical chemistry》2001,370(8):1091-1095
A PVC membrane electrode based on a cadmium–salen (N,N′-bis-salicylidene-1,2ethylenediamine) complex as an anion carrier is described. The electrode has an anti-Hofmeister selectivity
sequence with a preference for thiocyanate at pH 1.5–11.0. It has a linear response to thiocyanate from 1.0 × 10–6 to 1.0 × 10–1 mol L–1 with a slope of 59.1 ± 0.2 mV per decade, and a detection limit of 7 × 10–7 mol L–1. This electrode has high selectivity for thiocyanate relative to many common organic and inorganic anions. The proposed sensor
has a fast response time of approximately 15 s. It was applied to the determination of thiocyanate in a milk sample.
Received: 1 December 2000 / Revised: 19 April 2001 / Accepted: 30 April 2001 相似文献
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Bhargav Patel Anish Kumar Shobhana K. Menon 《Journal of inclusion phenomena and macrocyclic chemistry》2009,64(3-4):239-247
A highly selective PVC membrane electrode was prepared for thiocyanate (SCN?) determination, based on macrotricyclic binuclear Cu(II)–Schiff base complex as an ionophore. The novel macrotricyclic compound (cryptand) was synthesized by condensation of 4,4′-diamino-dibenzo-18-crown-6 with bis(4-formyl phenyl)terephthalate under high-dilution condition and the structure was confirmed by FT-IR, 1H NMR,13C NMR and MS studies. The Cu(II) complex of the compound was prepared and was examined for use as anion-selective electrode as a carrier which displays an anti-Hofmeister selectivity sequence in following order: SCN? > ClO4 ? > NO3 ? > CN? > I? > CO3 2? > NO2 ? > Br? > Cl? > SO4 2? with a preference for thiocyanate ion over many common anions. The electrode has a linear dynamic range between 1.0 × 10?7 and 1.0 × 10?1 M, with a Nernstian slope of ?58.9 mV decade?1 and detection limit of 3.1 × 10?8 M. The working pH range of the sensor was found be in the range of 3.0–8.0. It exhibits a fast response time of 20 s and has a lifetime of about 2 months. Application of the electrode for determination of thiocyanate in waste water samples and in human urine samples have also been demonstrated. 相似文献
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Xiu-Li Wang Chuang Xu Hong-Yan Lin Jian Luan Guo-Cheng Liu Ai-Xiang Tian Ju-Wen Zhang 《Transition Metal Chemistry》2012,37(8):751-756
A new POM-templated metal?Corganic complex [Cu4(L)7(H2O)12(SiMo12O40)2]·7H2O [L?=?N,N??-bis(3-pyridinecarboxamide)-1,6-hexane], has been hydrothermally synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction analysis. The results reveal that the complex is a 2D metal?Corganic coordination framework of [Cu4(L)7(H2O)12] n 8n+ cations containing decanuclear cycles with dimensions of ca. 17.55?×?57.42 ?, in which the SiMo12O40 4? anions act as non-coordinated anionic templates. The electrochemical properties of a bulk-modified carbon paste electrode of the complex have been investigated, and the results indicate that the complex-modified CPE has good electrocatalytic activity toward the reduction of nitrite in aqueous 1?M H2SO4 solution. 相似文献
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《Journal of Coordination Chemistry》2012,65(15):1645-1654
A new inorganic-organic hybrid, [Zn(phen)2(ppy)][{Zn(phen)2}{Zn(phen)2(H2O)}{P2W18O62}]?·?2H2O (phen?=?1,10′-phenanthroline, ppy?=?2-(5-phenylpyridin-2-yl)pyridine) (1), by using pre-prepared Wells–Dawson salt α-K6P2W18O62?·?15H2O as precursor, has been synthesized under hydrothermal conditions. Compound 1 was characterized by single-crystal X-ray diffraction, elemental analyses, IR spectrum and cyclic voltammetry. Yellow crystals crystallized in the monoclinic space group P2 (1)/c with a?=?16.2450(11)?Å, b?=?17.0918(11)?Å, c?=?43.640(3)?Å, β?=?92.0060(10)°, V?=?12109.4(14)?Å3, Z?=?4. The title compound represents a novel zero-dimensional structure based on bisupporting Wells–Dawson POM: one terminal oxygen atom located in the “belt” site and another located in the “cap” site of the same hemisphere of the polyanion are coordinated by Zn2+ cations. Compound 1 also contains the isolated secondary metal complex [Zn(phen)2(ppy)]2+ with two different organic ligands phen and ppy. 相似文献
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XIONG Guo-Xiang SHEN Shu-Yin YE Jian-Ping ZHOU Qing-Fu XU Hui-JunLaboratory of Photochemistry Institute of Photographic Chemistry Chinese Academy of Sciences Beijing China 《中国化学》1997,15(5):443-449
A novel zinc phthalocyanine containing four 17-crown-5 ether voids(17C5ZnPc) has been synthesized and characterized. UV-visible absorption and fluorescence emission spectra and as-sociated photophysical parameters have been determined. In contrast to most of the crown ether substituted phthalocyanines, no cofacial dimer formation is observed in the presence of alkali metal salts. In addition to the fluorescence at 710 nm from S1, a strong upper excited state (Soret 52) emission around 424 nm has been detected for the first time in the phthalocyanine series. Fluorescence decay of S1 and S2 emission can be analyzed by mono- and biexponential fits respectively. X-ray structure analysis showed that the crown ether unit is conformationally deformed and oblate that may account for the unusual spectroscopic properties. 相似文献
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Corneliu Sergiu Stan Nathalie Marcotte Marius Sebastian Secula Marcel Popa 《Journal of Sol-Gel Science and Technology》2014,69(1):207-213
The paper describes the preparation of a new photoluminescent silica aerogel by embedding a new Tb(III) complex in a silica matrix by using N-hydroxysuccinimide as ligand. The Tb(III) complex prepared at a metal to ligand ratio of 1:3 (mol%) exhibits strong photoluminescence as a result of specific radiative transitions within the Tb(III) cation with the most intense peak located at 543 nm due to 5D4 → 7F5 transition. The synthesized complex was doped in the silica matrix through a catalyzed sol–gel process. After ageing in ethanol, the alcogel was dried under supercritical regime by exchanging the ethanol with liquid carbon dioxide followed by supercritical evaporation. The leaching of the free complex from the alcogel during ageing and solvent exchange phases was found to be minimal most likely due to the interactions between chemical groups of complex with those specific to silica matrix. The obtained regular shaped monolithic aerogel preserved the remarkable photoluminescent properties and also improved the thermal stability of the free complex. Both, the free complex and doped aerogel were characterized through thermal analysis, FT-IR, powder X-ray diffraction, Scanning electron microscopy and fluorescence spectroscopy. For comparison purposes, an undoped silica aerogel was also prepared and investigated through FT-IR, BET analysis and powder X-ray diffraction. The excellent photoluminescent properties might recommend the prepared aerogel for applications in optoelectronic devices where photonic conversion materials are required. 相似文献
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《Journal of Coordination Chemistry》2012,65(5):457-465
A novel complex {[Zn(azpy)2(dca)(H2O)2]·ClO4·azpy·2H2O}n (1) has been synthesized and structurally and spectroscopically characterized, where azpy is the 4,4′-azopyridine and dca the dicyanamide. The crystal structure analysis of 1 shows that in 1 the dca ligands act as μ 1,5-bridges linking the zinc(II) ions into 1D covalent bonding chains. The zinc(II) ion lies in a distorted octahedral environment completed by two nitrogen atoms from two terminal azpy groups, two nitrogen atoms from two dca bridges, and two water molecules. The most striking feature of 1 is that the 1D covalent bonding chains are linked through O–H·N hydrogen bonds and π–π stacking interactions into a 3D supramolecular structure. 相似文献
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Peiyi Gao Yunfeng Xia Lele Yang Tengfei Ma Ling Yang Qianqiong Guo Shasheng Huang 《Mikrochimica acta》2014,181(1-2):205-212
We have developed an aptasensor for adenosine triphosphate (ATP) based on an electrode-supported lipid bilayer membrane. The assay is based on a conformational change that is induced after binding the target which modulates the electron transfer rate in the conductive path. The method is highly sensitive, stable, and repeatable. The detection limit for ATP is 50 nM, and the dynamic range extends to 3.2 μM, which covers the concentration range of ATP in cell lysates (from 0.1 to 1 μM). The method also holds promise in that it may be transferred to submicro- or nano-scale electrodes so to enable intracellular monitoring of ATP. Figure
An aptasensor for adenosine triphosphate based on an electrode-supported lipid bilayer membrane in principle of target-binding induced conformational change to modulate the electron transfer rate in the conductive path. 相似文献
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The intramolecular zinc bis-proline-phenol complex 2a was found to promote enantioselective iodolactonization reactions of both electron-rich and electron-poor 5-aryl-5-hexenoic acids affording δ-iodolactones in good chemical yields with up to 82% enantiomeric excess. The reactions were found to be insensitive to air and moisture, providing an experimentally simple protocol for synthetically useful compounds. 相似文献
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Jianbo Jia 《Mikrochimica acta》2008,163(3-4):237-241
A novel hydrogen peroxide biosensor was fabricated that is based on horseradish peroxidase–Au nanoparticles immobilized on a viologen-modified glassy carbon electrode (GCE) by amino cation radical oxidation in basic solution. The immobilized BAPV acts as a mediator and a covalent linker between GCE and the Au nanoparticles. The biosensor exhibited fast response, good reproducibility, and long-term stability. 相似文献
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《Electrochemistry communications》2001,3(5):219-223
A liquid–liquid interface supported on a metallic electrode has been used to study ion transfer (IT) and electron transfer (ET) reactions by cyclic voltammetry. The system is composed of an aqueous droplet supported on a platinum disc electrode and immersed into an organic electrolyte solution. Depending on the nature of the dissolved species present in the aqueous solution, and in the organic electrolyte solution, different electrochemical coupled reactions can be observed. This method enables a fast and convenient method to measure standard transfer potentials for example of ionised drug molecules. 相似文献
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A novel pentaazadentate bismacrocyde was synthesized through an improved procedure of 1:1 Schiff base condensation of diformyltripyrrane with 3, 4, 3', 4'-tetraamino-biphenyl hydrochloride using Ph2 as template ion, in which the condensed byproduct water was removed efficiently to make the yield over 90%. Then the bismacrocyclic ligand reacted with cadmium chloride to yield the title metal complex with molecular weight being 1200.4 by TOF MS and the λmax being 766 nm. 相似文献
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Long Yang Guang-Can Wang Yong-Jun Liu Jing-Jing An Min Wang 《Analytical and bioanalytical chemistry》2013,405(8):2545-2552
SiO2 nanosheets (SNS) have been prepared by a chemical method using montmorillonite as raw material and were characterized by scanning electron microscopy and X-ray diffraction. SiO2 nanosheet–Nafion nanocomposites with excellent conductivity, catalytic activity, and biocompatibility provided an extremely hydrophilic surface for biomolecule adhesion. Chitosan was used as a cross-linker to immobilize acetylcholinesterase (AChE), and Nafion was used as a protective membrane to efficiently improve the stability of the AChE biosensor. The AChE biosensor showed favorable affinity for acetylthiocholine chloride and catalyzed the hydrolysis of acetylthiocholine chloride with an apparent Michaelis–Menten constant of 134 μM to form thiocholine, which was then oxidized to produce a detectable and fast response. Based on the inhibition by pesticides of the enzymatic activity of AChE, detection of the amperometric response from thiocholine on the biosensor is a simple and effective way to biomonitor exposure to pesticides. Under optimum conditions, the biosensor detected methyl parathion, chlorpyrifos, and carbofuran at concentrations ranging from 1.0?×?10?12 to 1?×?10?10?M and from 1.0?×?10?10 to 1?×?10?8?M. The detection limits for methyl parathion, chlorpyrifos, and carbofuran were 5?×?10?13?M. The biosensor developed exhibited good sensitivity, stability, reproducibility, and low cost, thus providing a new promising tool for analysis of enzyme inhibitors. Figure
Performances and detection pesticides of a SiO2 nanosheet biosensor 相似文献
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Submicron-sized cationic polystyrene shell particles with active ester groups were effectively self-assembled on hydrophobic surfaces of cross-linked polystyrene (PST) particles, uncharged core particles with ca. 8.5-µm diameter in aqueous systems. The hydrophobic interactions between the shell particles and core particles play a key role in heterocoagulation. The resulting heterocoagulates were highly physically stable in water, and the morphology was controlled by several factors including the solid content of latex, self-assembling time, and electrolyte concentration. Composite polymer particles with a core–shell structure were successfully obtained from the heterocoagulates by heat treatment for 3 h at a temperature above the glass transition temperature (Tg) of the cationic polymer shell particles. 相似文献