共查询到19条相似文献,搜索用时 78 毫秒
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80年代Hill等["在蛋白质的电化学研究中加人氧化还原促进剂以提高电极反应速率.但最近的研究表明,电极材料的选择、蛋白质的纯度和溶液的离子强度等都影响反应速率和吸附行为['.我们曾选用悬汞电极在不加促进剂的情况下研究铜锌超氧化物歧化酶Cu。Zn。SOD的电化学性质,并获得较好的结果['j.本文研究了钻(I)取代铜锌超氧化物歧化酶CO。CO。SOD的氧化还原行为,首先用热解石墨电极对CO。CO。SOD进行循环伏安研究,获得了电极反应为扩散控制的可逆的电化学过程;然后用光谱电化学技术进行论证,由2种方法得到了在CO。CO。… 相似文献
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采用溴化十六烷基三甲基铵(CTAB)分散的单壁碳纳米管(SWNTs)将铁蛋白(Ft)固定在玻碳电极(GCE)表面,制备了铁蛋白-单壁碳纳米管-溴化十六烷基三甲基铵膜修饰玻碳电极(Ft-SWNTs-CTAB/GCE)。透射电子显微镜和原子力显微镜用于该膜的形貌表征,红外反射吸收光谱表明复合膜中的Ft保持原有的天然结构。采用循环伏安(CV)法研究了Ft在此修饰电极上的直接电化学和Ft中铁储存和铁释放的机理:在电化学还原过程中,Fe3+从蛋白质中还原出来,并在电化学氧化过程中重新进入到蛋白质内,CV曲线上有较好的氧化还原峰,峰电流较大,响应信号较好。利用去铁铁蛋白进行对比实验,进一步证实了Ft在SWNTs-CTAB修饰电极上的铁储存和铁释放过程。 相似文献
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在水溶液中制备了掺杂蒽醌磺酸盐(AQS)的聚吡咯(PPy)/玻碳复合膜修饰电极,采用循环伏安法和旋转圆盘电极技术研究了该修饰电极在不同pH值溶液中的电化学行为以及在pH=5.5的磷酸盐缓冲溶液中对氧还原反应的电催化性能和动力学.结果表明,与裸玻碳电极相比,PPy膜的存在不仅降低了AQS的反应电位和峰电位差,而且增大了其氧化还原反应的峰电流,H2AQ/HAQ-氧化还原对的电离常数为9.5.AQS/PPy膜修饰电极上氧的还原主要是两电子还原为H2O2的不可逆过程,H2AQ对氧还原反应起主要催化作用,还原过程符合异相氧化还原催化机理.该修饰电极具有良好的电化学重现性. 相似文献
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氧化还原蛋白质在模拟生物膜修饰电极上的直接电化学 总被引:8,自引:0,他引:8
评述了氧化还原蛋白在模拟生物膜这种新型的化学修饰电极上的直接电化学研究的进展。对蛋白质在表面活性剂薄膜电极和多层复合薄膜电极上的电化学行为、模拟生物膜的超分子结构以及蛋白质在该类薄膜修饰电极上对不同底物的电催化性质进行了较详细的介绍。 相似文献
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细胞色素c突变体F82H的表面增强拉曼和电化学研究 总被引:1,自引:0,他引:1
应用表面增强拉曼光谱和循环伏安法研究了细胞色素c及其突变体F82H的氧化还原性质,结果表明苯丙氨酸对组氨酸的取代使得蛋白质结构更为稳定,相对于原体蛋白质,突变体的氧化还原电位向负电位方向移动,这被归因于由氧化还原过程中伴随着配体转换反应影响所致。 相似文献
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肌红蛋白在灿烂甲酚蓝修饰电极上的可逆电子传递反应 总被引:3,自引:1,他引:2
利用循环电位吸收法和电位阶跃计时吸收法在薄层电解池中研究了肌红蛋白在灿烂甲酚蓝(BCB)修饰电极上和BCB溶液中的电化学行为。实验表明肌红蛋白可以发生可逆的还原和氧化反应,完全还原和氧化分别需要20和100s, 氧化还原反应的标准速率常数被估算为5.6×10^-^4cm·s^-^1, 并且稳定性很好, 没有蛋白质变性反应发生。用光谱电化学方法测得该反应的标准电极电位和电子转移数与肌红蛋白相符。光电子能谱实验表明肌红蛋白没有吸附在BCB修饰电极上, 对BCB修饰电极促进肌红蛋白的电子转移机理作了初步探讨。 相似文献
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In this tutorial review the basic approaches to establish electrochemical communication between redox-active proteins and electrodes are elucidated and examples for applications in electrochemical biosensors, biofuel cells and nanotechnology are presented. The early stage of protein electrochemistry is described giving a short overview over electron transfer (ET) between electrodes and proteins, followed by a brief introduction into experimental procedures for studying proteins at electrodes and possible applications arising thereof. The article starts with discussing the electrochemistry of cytochrome c, the first redox-active protein, for which direct reversible ET was obtained, under diffusion controlled conditions and after adsorption to electrodes. Next, examples for the electrochemical study of redox enzymes adsorbed on electrodes and modes of immobilization are discussed. Shortly the experimental approach for investigating redox-active proteins adsorbed on electrodes is outlined. Possible applications of redox enzymes in electrochemical biosensors and biofuel cells working by direct ET (DET) and mediated ET (MET) are presented. Furthermore, the reconstitution of redox active proteins at electrodes using molecular wire-like units in order to "wire" the proteins to the electrode surface and possible applications in nanotechnology are discussed. 相似文献
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P.N. Bartlett 《Journal of Electroanalytical Chemistry》1991,300(1-2)
Electrodes made from single crystals of tetrathiafulvalenium tetracyanoquinodimethanide (TTF. TCNQ) have been used to study the electrochemistry of the conducting organic salt and to investigate the mechanism of the electrochemical oxidation of glucose oxidase at conducting salt electrodes.The single crystal electrodes exhibit much lower non-Faradaic currents than the corresponding polycrystalline electrodes prepared as sublimed films or as pressed pellets. This leads to much lower background current levels and hence more clearly defined electrochemistry for solution species. Studies of the ac impedance behaviour and the electrochemistry of outer sphere redox species indicate that TTF·TCNQ electrodes behave as conventional metallic electrodes within their stable potential range.Results for the electrochemistry of glucose oxidase at the single crystal electrodes are inconsistent with a simple homogeneous mediation mechanism or with simple heterogeneous redox catalysis. Similarities with results obtained for TTF modified glucose oxidase suggest that the enzyme may undergo direct electrochemistry after modification by hydrophobic interaction with TTF molecules derived from the conducting salt electrode. 相似文献
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《Electroanalysis》2004,16(15):1193-1204
The knowledge of the redox chemistry of nucleic acids (NA) is of paramount importance in cancer and aging research. Charge migration through DNA is also involved in biologically relevant functions such as DNA damage and repair. In the first part of this article the main aspects of the electrochemistry of nucleic acids at solid electrodes are revised, including redox processes, photoelectroactivity and electrical conductivity. In the second part, an overview of its applications is presented. Methods for electrochemical detection of NA, NA‐based biosensors for detection of nonnucleic acid molecules, studies on the nature and dynamics of interactions and structural conformations of NA, are some applications that take advantage of NA electrochemistry at solid electrodes. 相似文献
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M. Roger A. de Poulpiquet A. Ciaccafava M. Ilbert M. Guiral M. T. Giudici-Orticoni E. Lojou 《Analytical and bioanalytical chemistry》2014,406(4):1011-1027
How the redox proteins and enzymes involved in bioenergetic pathways are organized is a relevant fundamental question, but our understanding of this is still incomplete. This review provides a critical examination of the electrochemical tools developed in recent years to obtain knowledge of the intramolecular and intermolecular electron transfer processes involved in metabolic pathways. Furthermore, better understanding of the electron transfer processes associated with energy metabolism will provide the basis for the rational design of biotechnological devices such as electrochemical biosensors, enzymatic and microbial fuel cells, and hydrogen production factories. Starting from the redox complexes involved in two relevant bacterial chains, i.e., from the hyperthermophile Aquifex aeolicus and the acidophile Acidithiobacillus ferrooxidans, examination of protein–protein interactions using electrochemistry is first reviewed, with a focus on the orientation of a protein on an electrochemical interface mimic of a physiological interaction between two partners. Special attention is paid to current research in the electrochemistry of essential membrane proteins, which is one mandatory step toward the understanding of energy metabolic pathways. The complex and challenging architectures built to reconstitute a membrane-like environment at an electrode are especially considered. The role played by electrochemistry in the attempt to consider full bacterial metabolism is finally emphasized through the study of whole cells immobilized at electrodes as suspensions or biofilms. Before the performances of biotechnological devices can be further improved to make them really attractive, questions remain to be addressed in this particular field of research. We discuss the bottlenecks that need to be overcome in the future. 相似文献
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Graziela C. Sedenho Ayaz Hassan João C.P. de Souza Frank N. Crespilho 《Current Opinion in Electrochemistry》2022
Understanding the biocatalytic or the interfacial electron transfer processes of redox enzymes is decisive to develop high-performance biofuel cells, mimetic catalysts, bioelectrosynthesis reactors, biosensors, and bioelectronic devices. The state-of-art of redox enzyme electrochemistry lies in using in situ and operando instrumentation, in which protein electrochemistry is resourcefully coupled to or hyphenated with numerous analytical techniques. Nevertheless, there is still a lot to research about the manipulation of redox proteins in the unusual sample holding environments, and bioelectrodes engineering emerges as a key. Here, we discuss these challenges in detail, focusing on contemporary instrumentation setups. 相似文献
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Unique structured nanomaterials can facilitate the direct electron transfer between redox proteins and the electrodes. Here, in situ directed growth on an electrode of a ZnO/Cu nanocomposite was prepared by a simple corrosion approach, which enables robust mechanical adhesion and electrical contact between the nanostructured ZnO and the electrodes. This is great help to realize the direct electron transfer between the electrode surface and the redox protein. SEM images demonstrate that the morphology of the ZnO/Cu nanocomposite has a large specific surface area, which is favorable to immobilize the biomolecules and construct biosensors. Using glucose oxidase (GOx) as a model, this ZnO/Cu nanocomposite is employed for immobilization of GOx and the construction of the glucose biosensor. Direct electron transfer of GOx is achieved at ZnO/Cu nanocomposite with a high heterogeneous electron transfer rate constant of 0.67 ± 0.06 s(-1). Such ZnO/Cu nanocomposite provides a good matrix for direct electrochemistry of enzymes and mediator-free enzymatic biosensors. 相似文献