排序方式: 共有77条查询结果,搜索用时 15 毫秒
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5—(4‘—溴—2’—羧基苯偶氮)罗丹宁与铜(Ⅱ)的显色反应及其应用 总被引:3,自引:1,他引:3
本报道了新显色剂5-(4’-溴-2’-羧基苯偶氮)罗丹宁的合成及在水溶液中的离解常数K1和K2,研究了该显色剂与铜(Ⅱ)的显色反应,在弱酸性时,试剂与铜(Ⅱ)形成摩尔比2:1的络合物,摩尔吸光系数为8.9×10^4L.mol^-1.cm^-1。当铜的浓度在0~2.7mg/L的范围内符合比耳定律。用分光光度法测定了合金中铜的含量。 相似文献
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Yu P Lin Y Xiang L Su L Zhang J Mao L 《Langmuir : the ACS journal of surfaces and colloids》2005,21(20):9000-9006
This letter describes the formation and possible electrochemical applications of molecular films of water-miscible imidazolium-based ionic liquids (ILs) on glassy carbon (GC) electrodes. X-ray photoelectron spectroscopy (XPS) and electrochemical results indicate that the water-miscible ILs used in this study can interact with the GC electrode and form molecular films on the electrode surface. The formed molecular films are found to possess striking electrochemical properties such as electrocatalysis toward ascorbic acid (AA) and the capability to facilitate direct electron transfer of horseradish peroxidase (HRP). This demonstration would pave the way for new electrochemical applications of water-miscible ILs and is envisaged to be useful for the investigation of the electrochemical properties of water-miscible ILs in aqueous media provided the same counteranion is used as the supporting electrolyte. 相似文献
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Electrostatic layer-by-layer assembled carbon nanotube multilayer film and its electrocatalytic activity for O2 reduction 总被引:1,自引:0,他引:1
Zhang M Yan Y Gong K Mao L Guo Z Chen Y 《Langmuir : the ACS journal of surfaces and colloids》2004,20(20):8781-8785
Multilayer films of shortened multiwalled carbon nanotubes (MWNTs) are homogeneously and stably assembled on glassy carbon electrodes with the layer-by-layer (LBL) method, based on electrostatic interaction of positively charged poly(diallyldimethylammonium chloride) and negatively charged and shortened MWNTs. The film assembly and electrochemical property as well as the electrocatalytic activity toward O2 reduction of the MWNT multilayer film are studied. Scanning electron microscopy, the quartz crystal microbalance technique, ultraviolet-visible-near-infrared spectroscopy, and cyclic voltammetry are used for characterization of film assembly. Experimental results revealed that film growth is uniform, almost with the same coverage of the MWNTs in each layer, and that the assembled MWNTs are mainly in the form of small bundles or single tubes on the electrodes. Electrochemical studies indicate that the LBL assembled MWNT films possess a remarkable electrocatalytic activity toward O2 reduction in alkaline media. This property, combined with the well-dispersed, porous and conductive features of the MWNT film illustrated with the LBL method, suggests the potential application of the MWNT film for constructing an efficient alkaline air electrode for energy conversions. 相似文献
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Yanan Jiang Wenjie Ma Yujuan Qiao Yifei Xue Jiahao Lu Jun Gao Nannan Liu Fei Wu Prof. Ping Yu Prof. Lei Jiang Prof. Lanqun Mao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(31):12895-12899
Biological ion channels and ion pumps with sub-nanometer sizes modulate ion transport in response to external stimuli. Realizing such functions with sub-nanometer solid-state nanopores has been an important topic with wide practical applications. Herein, we demonstrate a biomimetic photoresponsive ion channel and photodriven ion pump using a porphyrin-based metal–organic framework membrane with pore sizes comparable to hydrated ions. We show that the molecular-size pores enable precise and robust optoelectronic ion transport modulation in a broad range of concentrations, unparalleled with conventional solid-state nanopores. Upon decoration with platinum nanoparticles to form a Schottky barrier photodiode, photovoltage across the membrane is generated with “uphill” ion transport from low concentration to high concentration. These results may spark applications in energy conversion, ion sieving, and artificial photosynthesis. 相似文献
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Taotao Feng Wenliang Ji Yue Zhang Fei Wu Qiao Tang Huan Wei Prof. Lanqun Mao Prof. Meining Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23651-23655
Electrochemical sensing performance is often compromised by electrode biofouling (e.g., proteins nonspecific binding) in complex biological fluids; however, the design and construction of a robust biointerface remains a great challenge. Herein, inspired by nature, we demonstrate a robust polydopamine-engineered biointerfacing, to tailing zwitterionic molecules (i.e., sulfobetaine methacrylate, SBMA) through Michael Addition. The SBMA-PDA biointerface can resist proteins nonspecific binding in complex biological fluids while enhancing interfacial electron transfer and electrochemical stability of the electrode. In addition, this sensing interface can be integrated with tissue-implantable electrode for in vivo analysis with improved sensing performance, preserving ca. 92.0% of the initial sensitivity after 2 h of implantation in brain tissue, showing low acute neuroinflammatory responses and good stability both in normal and in Parkinson′s disease (PD) rat brain tissue. 相似文献
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Prof. Ping Yu Huan Wei Peipei Zhong Yifei Xue Dr. Fei Wu Dr. Yang Liu Prof. Junjie Fei Prof. Lanqun Mao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(50):22841-22847
The development of new principles and techniques with high neuronal compatibility for quantitatively monitoring the dynamics of neurochemicals is essential for deciphering brain chemistry and function but remains a great challenge. We herein report a neuron-compatible method for in vivo neurochemical sensing by powering a single carbon fiber through spontaneous bipolar electrochemistry as a new sensing platform. By using ascorbic acid as a model target to prove the concept, we found that the single-carbon-fiber-powered microsensor exhibited a good response, high stability and, more importantly, excellent neuronal compatibility. The microsensor was also highly compatible with electrophysiological recording, thus enabling the synchronous recording of both chemical and electrical signals. The sensing principle could be developed for in vivo monitoring of various neurochemicals in the future by rationally designing and tuning the electrochemical reactions at the two poles of the carbon fiber. 相似文献
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聚N,N-双水杨醛乙二胺合钴修饰超微电极的制备及其在一氧化氮测定中应用的研究 总被引:6,自引:0,他引:6
通过电化学聚合法制备了聚N,N-双水杨醛乙二胺合钴[polyCo(Salen)]修饰超微电极,研究了该修饰电极的电催化性质及其在一氧化氮(NO)测定中的应用.实验结果表明,polyCo(Salen)修饰超微电极对NO的测定有高的灵敏度,NO的浓度在2.0×10-8~2.8×10-6mol/L范围内,电流与浓度呈良好的线性关系,线性相关系数为0.9998,检出限为1.0×10-8mol/L;该电极进一步修饰Nafion后,生物体中常见的物质如抗坏血酸、儿茶酚胺类神经递质的代谢物、NO的氧化产物NO-2等不干扰测定.本传感器可以满足NO在体分析的需要. 相似文献
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Yanan Jiang Wenjie Ma Yujuan Qiao Yifei Xue Jiahao Lu Jun Gao Nannan Liu Fei Wu Ping Yu Lei Jiang Lanqun Mao 《Angewandte Chemie (International ed. in English)》2020,59(31):12795-12799
Biological ion channels and ion pumps with sub‐nanometer sizes modulate ion transport in response to external stimuli. Realizing such functions with sub‐nanometer solid‐state nanopores has been an important topic with wide practical applications. Herein, we demonstrate a biomimetic photoresponsive ion channel and photodriven ion pump using a porphyrin‐based metal–organic framework membrane with pore sizes comparable to hydrated ions. We show that the molecular‐size pores enable precise and robust optoelectronic ion transport modulation in a broad range of concentrations, unparalleled with conventional solid‐state nanopores. Upon decoration with platinum nanoparticles to form a Schottky barrier photodiode, photovoltage across the membrane is generated with “uphill” ion transport from low concentration to high concentration. These results may spark applications in energy conversion, ion sieving, and artificial photosynthesis. 相似文献
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