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1.
用电化学现场表面增强拉曼光散射光谱研究了Fe(CN)^3-/4-6在金电极表面的氧化还原过程及吸附行为,结果表明,Fe(CN)^3-6相对于Fe(CN)^4-6能更强烈地吸会在金电极表面上,并通过配体CN^-的N端吸附在电极表面。  相似文献   

2.
林祥钦  王新豫 《分析化学》1996,24(4):489-493
本报道一种能很好适用于固态分析了现场研究的外反射式微盘电极薄层显微红外光谱电化学池设计。该池使用100μm直径微铂盘工作电极,银盘参比电极和同心环形辅助电极。在PEG400/LiCLO4体系中,池参数为:薄层厚0.6μm,表观薄层电阻14mΩ,充电电容4×10^3pF,时间常数60ms,并测得常温下Fe(CN)6^3-/4-的表观扩散系数4×10^-7cm^2/s,获了良好分辨Fe(CN)6^3  相似文献   

3.
刘启旺  胡襄 《结构化学》1996,15(3):210-214
Fe3(CO)12和取代2,4-二硫代乙内酰脲反应,得到新的取代物Fe3(CO)8^-(:CNHC(S)C(CH3)2NH(μ3-S2),并进行了IR,^1HNMR,MS表征,测定了它的分析和晶体结构,讨论了杂环卡宾碎片:CNHC(S)C(CH3)2NH的取代位置,它是通过卡宾碳原子与Fe配位。  相似文献   

4.
推导并验证了新型阶跃伏安技术-常规二脉冲叠加四阶跃微分伏安法准可逆电极过程的理论电流方程式,同时研究了各项参数如扫描增量(Ea)、脉冲高度(△E)、传递系数(α)对峰电流函数(ψp)、峰电流(ip)、峰电位(Ep)和半峰宽(W1/2)的影响。运用理论ψp-1gks图和单纯形优化计算测量了Fe(CN)^3-6/Fe(CN)^4-y-KCl及Zn(Ⅱ)/Zn(Hg)-NaNO3体系的ks及α值,结果与  相似文献   

5.
亚铁氰化钾掺杂聚中性红膜修饰电极的制备及电分析特性   总被引:5,自引:0,他引:5  
孙元喜  周谷珍  周性尧 《分析化学》2000,28(10):1271-1279
对亚铁氰化钾掺杂的聚中性红膜修饰电极的制备及其电化学行为和Fe(CN)64-在该电极上的催化作用进行了研究。结果表明,该修饰电极对Fe(CN)64-存在较强的电催化作用,催化峰电流与Fe(CN)64-的浓度在 1.0×10-5~2.0×10-3 mol/L范围内呈良好的线性关系,检测限可达5×10-6mol/L  相似文献   

6.
双极安培滴定法测定易切钢中铅   总被引:1,自引:0,他引:1  
提出了在聚乙二醇(PEG)存在下,用四苯硼钠(TPB)滴定铅,以双碳电极安培滴定法指标滴定终点,等当点以后,由于过量的TPB在碳电极上的阳极氧化作用而引起电流的显著变化,响应较快,终点敏锐,研究了滴定的最佳条件,包括双极系统的选择,外加电压的影响,以及共存离子的干扰等,结果表明,大量的常见金属离子Fe^3+,Al^3+,Ce^3+,La^3+,Sb^3+Bi^3+,V5+,Mo^6+,W^6+,S  相似文献   

7.
用微电子平面工艺制备了带宽和边长分别为10、20、30μm的带形和正方形微电极阵列(BMEA和SMEA)。在K3Fe(CN)6溶液中研究了它们的电化学特性。边长为10μm的SMEA(工作电极总面积仅为9×10^-3mm^2)有最大的电流密度(12.1μA/mm^2)和最短的响应时间(5s)。同一硅片中任选5个SMEA其H2O2工作曲线的线性范围为0.1~5mmol/L,平均斜率为220nA/mmo  相似文献   

8.
林祥钦  章宏强 《分析化学》1993,21(11):1355-1358
本文阐述了一种新的光谱电化学技术-现场显微红外光谱电化学法的反射式方法的技术特点和优势,报告了一种适于水溶剂和非水溶剂的反射式现场显微红外光谱电化学池的设计,并首次在25um直径的超微铂盘工作电极上,对Fe(CN)^4-6/FE(CN)^3-6进行了现场显微红外光谱电化学的测量。  相似文献   

9.
谷胱甘肽能自组装吸附到金电极上形成单分子膜。该膜能阻止Fe(CN)6离子在金电极上还原,起离子闸门的作用。当溶液中加入La^3+或Ca^2+时,了穿透膜的能力得到改善。本课题应用循环伏安法和计时库仑法,在PH5.6的溶液中研究了La^3+的调控能力,与Ca^2+比较,发现在改变谷胱甘肽单分子膜的结构和Fe(CN)6离子的扩散系数方面,La^3+具有更强的能力。  相似文献   

10.
标题化合物(Me2SiSiMe2)〔η^5-(3-Me3SiC5H3)Fe(CO)2〕2/(μ-CO)2(A)分子中的Fe-Fe键被钠汞齐还原断裂,生成相应的双铁负离子,分别与MeCOCl、PhCOCl、PhCH2Cl、ClCH2COOC2H5和Ph3SnCl进行亲核取代反应,生成在铁原子上引入相应取代基的产物(Me2SiSiMe2)〔η^5-(3-Me3SiC5H3)Fe(CO)2R〕2(R:M  相似文献   

11.
纳米级微带金电极上葡萄糖氧化酶的固定.性质及应用   总被引:5,自引:0,他引:5  
实现了葡萄糖氧化酶以及葡萄糖氧化酶和电子传递媒体Fe(CN)^3^-~6同时在纳米级微带电极上的固定,用红外光谱和循环伏安对GOD/PPy微电极进行了表征, 研究了微带金电极上聚吡咯恒电位形成过程的动力学及葡萄糖氧化酶对其动力学过程的影响,探讨了微酶电极GOD/Fe(CN)^3^-~6/PPy对葡萄糖氧化的催化作用, 考察了PPy膜厚度和溶液中氧的存在对GOD/Fe(CN)^3^-~6/PPy微电极测定葡萄糖的影响.  相似文献   

12.
Enzylnebasedampcr()metricbiosensorsha\'eattractedincreasinginterestinthe1astt`xodecades.Inordertofabricate[heenzyn1elayer,considerahlceff()rtsha\,eheendcv()tcdt(1thedeveloprnent()fvari()ustechniquesf()rin1n1obilizingthcen/yn1c"2.Rcccntly.thcp()lyelectrolyte-proteincomplcx111ultilayerassen1blybyaIternateelectr()staticadsorptionhasbcenrep()rted',amullilaycrc()nsistingofalterl1atepolyethylenimineandglucoseoxidasclaycrswasassemb1edhyLv()veltl/>.ThesebioIllo1eculararthitecturesopenawaytoconstruct…  相似文献   

13.
利用磷酸盐缓冲溶液中吡咯的电聚合,将葡萄糖氧化酶(GOD)包埋在聚吡咯(PPy)基质中以构成生物功能电极。讨论了溶液pH和聚合电位对酶固定化的影响,并用IR和交流阻抗谱对酶膜进行表征。GOD的固定化只有当pH>5.5时才能实现,由此推测酶是以带负电的粒子嵌入PPy的。交流阻抗谱表明这一电极具有有界多孔电极的特征。探索了酶与电子传递体Fe(CN)_6~(3-)同时固定化的可行性。电化学固定化的GOD保持其生物催化活性,酶反应表观上遵循Michealis-Menten动力学。  相似文献   

14.
生物功能电极 III. 葡萄糖氧化酶的电化学固定化研究   总被引:5,自引:4,他引:5  
利用磷酸盐缓冲溶液中吡咯的电聚合, 将葡萄糖氧化酶(GOD)包埋在聚吡咯(PPy)基质中以构成生物功能电极。讨论了溶液pH和聚合电位对酶固定化的影响, 并用IR和交流阻抗谱对酶膜进行表征。GOD的固定化只有当pH>5.5时才能实现, 由此推测酶是以带负电的粒子嵌入PPy的。交流阻抗谱表明这一电极具有有界多孔电极的特征。探索了酶与电子传递体Fe(CN)_6~(3-)同时固定化的可行性。电化学固定化的GOD保持其生物催化活性, 酶反应表观上遵循Michealis-Menten动力学。  相似文献   

15.
Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and digital simulation techniques were used to investigate quantitatively the mechanism of electron transfer (ET) through densely packed and well-ordered self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid on gold, either pristine or modified by physically adsorbed glucose oxidase (GOx). In the presence of ferrocenylmethanol (FcMeOH) as a redox mediator, ET kinetics involving either solution-phase hydrophilic redox probes such as [Fe(CN)6]3-/4- or surface-immobilized GOx is greatly accelerated: [Fe(CN)6]3-/4- undergoes diffusion-controlled ET, while the enzymatic electrochemical conversion of glucose to gluconolactone is efficiently sustained by FcMeOH. Analysis of the results, also including the digital simulation of CV and EIS data, showed the prevalence of an ET mechanism according to the so-called membrane model that comprises the permeation of the redox mediator within the SAM and the intermolecular ET to the redox probe located outside the monolayer. The analysis of the catalytic current generated at the GOx/SAM electrode in the presence of glucose and FcMeOH allowed the high surface protein coverage suggested by X-ray photoelectron spectroscopy (XPS) measurements to be confirmed.  相似文献   

16.
IntroductionDirectelectrochemistryofenzymeshasarousedincreasinginterestofmanyresearchersasitisapreferablewayforproducingarealreagent1essbiosensor.Glucoseoxidase(GOD),beingaflavoprotein,iswell-knownduetoitswidespreaduseinthebiosensors'Recently,agreatnumberofpeoplehaveat-temptedtoachievedirectelectrontransferbetweenGODandvariouselec-trodes[l-19].Szucselal.determinedtheshapeandsizeoftheGODmoleculead-sorbedonagoldelectrodebyel1ipsometry['jandexamineddirectelectrontrans-ferbetweentheadsorbedenz…  相似文献   

17.
膜电阻对自组装膜修饰电极电化学行为的影响   总被引:4,自引:1,他引:3  
崔晓莉  江志裕 《电化学》2001,7(3):270-275
应用循环伏安和交流阻抗技术研究了 16烷基硫醇自组装膜修饰的金电极在Fe(CN) 63 - /Fe(CN) 64 - 溶液中的电化学行为 .无“针孔”缺陷的自组装膜对溶液与基底间的界面电子转移具有强烈的阻碍作用 ,当过电位较大时 ,In(I/ η)对 η1/2 之间具有良好的线性关系 .通过对Au/SAM /Hg模拟体系的电流———电压曲线进行测定 ,得到了自组装膜膜电阻的特征 .指出由于膜电阻的存在 ,自组装膜修饰电极在Fe(CN) 63 - /Fe(CN) 64 - 溶液中的行为实质上反映了膜自身的电阻特征  相似文献   

18.
Peng Y  Wei CW  Liu YN  Li J 《The Analyst》2011,136(19):4003-4007
This paper describes the fabrication and application of a complex electrode--Nafion film coating ferrocenylalkanethiol (FcC(11)SH) and encapsulated glucose oxidase (GOD) on a gold electrode. FcC(11)SH is employed as a mediator enabling the electron transfer between GOD and the electrode, GOD is encapsulated in polyacrylamide gel to improve the stability of the enzyme, and the Nafion film is coated on the modified electrode to eliminate interferents such as ascorbic acid, uric acid and acetaminophen in amperometric glucose detection. It is noticed that such a complex electrode exhibits excellent catalytic activity for glucose oxidation, and preserves the native structure of GOD and therefore its enzymatic activity. The encapsulated GOD retains more than 80% of its original biocatalytic activity even after 24 days, much longer than that of naked GOD molecules attached directly to the electrode. The oxidation peak current at the modified electrode shows a linear relationship with the glucose concentration in the range from 0.05 to 20 mM with a detection limit of 2.4 μM. In addition, the electrode displays a rapid response and good reproducibility for glucose detection, and has been successfully employed for glucose detection in blood plasma samples.  相似文献   

19.
Scanning electrochemical microscopy was used to examine electron transfer across a self-assembled monolayer of thiol-modified DNA duplexes on a gold electrode. The apparent rate constant for heterogeneous ET from a solution redox probe, Fe(CN)6(3-/4-), to the gold surface through ds-DNA was 4.6 (+/-0.2) x 10(-7) cm/s. With the addition of Zn2+, which resulted in the formation of a metalated DNA (M-DNA) monolayer, the rate constant increased to 5.0 (+/-0.3) x 10(-6) cm/s. Upon treating M-DNA with EDTA, the zinc ions were released from the monolayer and the original rate constant for the DNA duplexes was restored. The enhanced ET rate was also observed at a DNA monolayer treated with Ca2+ or Mg2+, which does not complex by the DNA bases to form M-DNA. The binding of these cations facilitated the monolayer penetration by the probe mediator Fe(CN)6(3-/4-) and accordingly caused an increased redox signal of the mediator at the ds-DNA-modified electrode. Cationic or neutral mediators were not blocked by the ds-DNA monolayer. These results suggest that although the increased electron transport through M-DNA could partially be ascribed to the intrinsic enhancement of electric conductivity of M-DNA, which has been confirmed by photochemical studies, the change in the surface charge of DNA monolayers on the electrode caused by the binding of metal ions to DNA molecules may play a more important role in the enhancement of current with M-DNA.  相似文献   

20.
林原  肖绪瑞 《应用化学》1991,8(3):80-82
用外层单电子快速转移的氧化还原剂二茂铁及其衍生物修饰电极,在电极/溶液界面作为电子传递的中介物,可使电极上进行的慢反应得到加速、起中介催化作用。目前研究较多的是共价键合和高分子膜的修饰,其他方式的修饰报道不多。用能实现分子有序化排列的L-B膜技术进行氧化还原电活性分子的修饰电极还未见报道。我们用L-B膜技术在SnO_2电极上修饰了二茂铁的衍生物-硬脂酸二茂铁酯(FcOCOC_(17)H_(35))双亲化合物,曾研究了修饰膜的电化学可逆行为和稳定性。本文研究硬脂酸二茂铁酯L-B膜修饰的SnO_2电极  相似文献   

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