酞菁锰-表面活性剂薄膜电极的电化学表征及其对三氯乙酸的电化学催化作用的研究

将酞菁锰（ＭｎＰｃ）掺入阳离子表面活性剂双十二烷基二甲基溴化铵（ＤＤＡＢ）的氯仿溶液，并涂布于热解石墨电极表面，待氯仿挥发后即制得ＭｎＰｃ－ＤＤＡＢ薄膜电极。循环伏安实验表明，在ＫＢｒ溶液中，该薄膜电极有两对还原氧化峰，第一对峰的Ｅｐｃ１＝－０．２７Ｖ，Ｅｐａ１＝０．０１Ｖ；第二对峰的Ｅｐｃ２＝－０．７６Ｖ，Ｅｐａ２＝－０．６２Ｖ（ｖｓ．ＳＣＥ）。本文着重探讨了第二对峰的电化学行为，估计了该体系的电荷传递扩散系数Ｄｃｔ和表观非均相电极反应速率常数Ｋ０′等电化学参数，并可将该薄膜电极用于催化三氯乙酸的电化学还原。     

酞菁锰—表面活性剂薄膜电极的电化学表征及其对三氯乙酸的电化学催 …

将酞菁锰（ＭｎＰｃ）掺入阳离子表面活性剂双十二烷基二甲基溴化铵（ＤＤＡＢ）的氯仿溶液，并涂布于热解石墨电极表面，待氯仿挥发后即制得ＭｎＰｃ－ＤＤＡＢ薄膜电极，循环伏安实验表明，在ＫＢｒ溶液中，该薄膜电极有两对还原氧化峰，第一对峰的Ｅｐｃｔ＝－０．２７Ｖ，Ｅｐａ１＝０．０１Ｖ；第二对峰的Ｅｐｃ２＝－０．７６Ｖ，Ｅｐａ２＝－０．６２Ｖ（ｖｓ．ＳＣＥ）。本文着重探讨了第二对峰的电化学行为，估计了该体系电     

酞菁镍—表面活性剂薄膜修饰电极及其催化性能的研究

将酞菁镍（ＮｉＰｃ）掺入阳离子表面活性剂双十二烷基二甲基溴化铵（ＤＤＡＢ）的氯仿溶液中，并涂布于热解石墨电极表面，待氯仿挥发后制得ＮｉＰｃ－ＤＤＡＢ薄膜电极。循环伏安实验表明，在ＫＢｒ溶液中，该薄膜电极有两对良好且稳定的还原氧化峰，第一对峰的Ｅｐｃ１＝－０．６４Ｖ，Ｅｐａｌ＝－０．６０Ｖ（ｖｓ．ＳＣＥ）；第二对峰的Ｅｐｃ２＝－０．８４Ｖ，Ｅｐａ２＝－０．８０Ｖ。本文着重探讨了第二对峰的电化学行为，     

双金属杂原子分子筛CrCoBEA的合成、波谱及催化性能研究

采用水热晶化法首次合成出ＢＥＡ结构含铬、钴，双金属杂原子分子筛ＣｒＣｏＢＥＡ，对晶化时间，晶化温度，成胶配比等合成条件进行了优化研究，采用ＸＲＤ，ＦＴＩＲ，ＵＶ－ＶｉｓＤＲＳ，ＥＳＲ及催化反应等方法测试其物相、波谱性质和催化性能，结果表明物质的量比为ＴＥＯＳ：０．０１７「Ｃｒ（ａｃａｃ）３」：０．０１７「Ｃｏ（ａｃａｃ）３」：（０．５８－０．６４）ＴＥＡＯＨ：０．０１Ａｌ（ＮＯ３）３：（１６－２０     

大黄酚的电化学行为及其应用研究

大黄酚在０．１５ｍｏｌ／Ｌ ＨＡｃ－ＮａＡｃ（ｐＨ４．９）底液中，出现一灵敏的示波极谱导数峰，峰电位为－０．４５Ｖ（ｖｓ，ＳＣＥ），峰电流与大黄酚浓度在２．０×１０＾－７－５．０×１０＾－６ｍｏｌ／Ｌ范围内成线性关系，检测限为２．０×１０＾－６ｍｏｌ／Ｌ。用于生药大黄中大黄酚的测定，回收率为９２．４％－１０８．４％。用多种电化学手段研究体系的电化学行为，测得电极反应电子数ｎ＝２。体系具有吸附性，并     

Fe（Ⅲ）—TEA—5—Br—PADAP—H2O2体系中催化波的研究及其应用

在０．２ｍｏｌ·Ｌ＾－１ＮＨ４Ｃｌ－ＮＨ３·Ｈ２Ｏ底液中，（ｐＨ为９．２６），得到一个极为灵敏的Ｆｅ（Ⅲ）－ＴＥＡ－５－Ｂｒ－ＰＡＤＡＰ－Ｈ２Ｏ２配合吸附催化波，其峰电位为－０．７１Ｖ（ｖｓ．ＳＣＥ）。铁浓度在１．８×１０＾－１０￣５．４×１０＾－６ｍｏｌ·Ｌ＾－１范围内与二阶导数波高呈线性关系。对该极谱波的性质进行了研究，证明是一种配合吸附催化波，并成功地应用于各类水样，钒催化剂中微量或痕量铁的     

磷钼杂多酸-L-半胱氨酸自组装超分子膜电极对亚硝酸根电催化还原的研究

制备了磷钼杂多酸－Ｌ－半胱氨酸自组装超分子膜电极（Ｐ２Ｍｏ１８－Ｌ－Ｃｙｓ／Ａｕ）。采用水平衰减全反射（ＡＴＲ－ＦＴＩＲ）光谱表征了膜的组成。研究了该膜电极的电化学性质，发现它在１．０ ｍｏｌ／Ｌ　Ｈ２ＳＯ４溶液中，于０．０～０．７Ｖ（ｖｓ．ＳＣＥ）间ＣＶ扫描出现两对稳定、可逆的氧化还原峰，其中峰电位分别为Ｅｍ１＝０．３３４ Ｖ，Ｅｍ２＝０．１８８Ｖ，对应着Ｐ２Ｍｏ１８Ｏ_(６２)~(６－)的两步２电子－２质子反应；计时库仑法计算了薄膜内的电子传递系数Ｄ为５．０１ × １０~（－８）ｃｍ２·ｓ～（－１）。该膜电极对酸性溶液中的ＮＯ_２~－有明显的电催化还原作用，初步探讨了电催化机理。用差分脉冲伏安法（ＤＰＶ）测定其还原峰电流与ＮＯ_２~－的浓度在２．０ ×１０~（－６）～２．０ × １０~（－４）ｍｏｌ／Ｌ范围内呈良好的线性关系，相关系数为０．９９５３，检测限５．０×１０~（－７）ｍｏｌ／Ｌ。该电极用于模拟水样中ＮＯ_２~－的测定，结果满意。     

修饰微带金电极上细胞色素C电极过程的热力学研究

研究了细胞色素Ｃ（Ｃｙｔ．Ｃ）在一种新的电子转移促进剂４，６－二甲基－２－巯基嘧啶修饰微带金电极（ＤＭＭＰ／Ａｕ）上的氧化还原热力学；求得Ｃｙｔ．Ｃ在ＤＭＭＰ／Ａｕ电极上反应的标准电极电位Ｅ＾ｏ，熵变△Ｓ＾ｏ，焓变△ＩＩ＾ｏ及Ｇｉｂｂｓ自由能的改变△Ｇ１０值分别为：０．２７２Ｖ（ｕｓ．ＮＨＥ），－１２３．７Ｊ．ｍｏｌ＾－＾１，－６３．１ｋＪ．ｍｏｌ．ｍｏｌ＾－＾１和－２６．２ｋＪ．ｍｏｌ＾－＾１（     

硫堇衍生化自组装膜修饰金电极的电化学性质及其对抗坏血…

将硫堇共价键合到自组装在金电极表面的半胱胺单分子层上，制成了衍生化自组装单分子膜修饰电极，并用电化学方法研究了它的电化学性质，循环伏安图显示其在ｐＨ＝７．７的磷酸盐缓冲液中，于－０．４５～＋０．５０Ｖ（ｖｓ．ＳＣＥ）范围内有２对氧化还原峰，峰电位分别为Ｅｐａ＝２１４ｍＶ，Ｅｐｃ＝８２ｍＶ，Ｅ＾２ｐａ＝－７５ｍＶ，Ｅ＾２ｐｃ－－１６０ｍＶ（ｖｓ．ＳＣＥ），ｐＨ在５．０～９．０范围内，峰１有２个质子参     

金属离子与卟啉的嵌入反应动力学研究──Ⅶ．一元酸根催化Cu(Ⅱ)与溴化间－四(N－乙酸甲酯基－3－吡啶基)卟啉的配位反应

研究了在３５±０．１℃、离子强度０．５ｍｏｌ／Ｌ（ＫＣｌ）条件下，甲酸根、乙酸根、丙酸根和丁酸根分别催化Ｃｕ（Ⅱ）离子与四溴化间－四（Ｎ－乙酸甲酯基－３－吡啶基）卟啉（Ｈ２Ｔβ－Ｎ－ＡＣＭｓｐｙＰＢｒ４）的反应动力学及其机理，该类反应对卟啉和Ｃｕ（Ⅱ）离子均为一级反应，反应动力学方程为：ｄ［ＣｕＰ＾４＋］／ｄｔ＝ｋ｛１．０＋ｂ［Ａ＾－］）／（１．０＋Ｋ３，４．［Ｈ＾＋］＾２｝［Ｃｕ＾２＋］［Ｐ］Ｔ     

酞菁钴－表面活性剂薄膜修饰电极及其催化性能

将酞菁钴(CoPc)掺入阳离子表面活性剂双十二烷基二甲基溴化铵(DDAB)的氯仿溶液,并涂布于热解石墨电极表面,待氯仿挥发后即制得CoPc-DDAB薄膜电极。循环伏安实验表明,在KBr溶液中,该薄膜电极有一对良好且稳定的还原氧化峰,E_pc=-0.45V,E_pa=-0.24V(vs.SCE).探讨了该体系的电化学行为,估计了该体系的电化学参数。可将该薄膜电极用于催化卤代乙酸的电化学还原。     

四磺酸酞菁镍-表面活性剂薄膜电极催化性能研究

四磺酸酞菁镍阴离子(NiPcTS^-^4)在水溶液中可借助离子交换进入阳离子表面活性剂双十二烷基二甲基溴化铵(DDAB)薄膜电极, 从而形成NiPcTS^-^4-DDAB薄膜电极。循环伏安实验表明, 在KBr溶液中, 该薄膜电极有一对良好的还原氧化峰, 阴阳极峰电位分别为-0.83V和-0.74V(vs.SCE)。本文探讨了该薄膜电极的电化学行为, 测定了该体系的电化学参数如电荷传递扩散系数Dct和非均相电极反应速率常数k°'等。可将NiPcTS^-^4-DDAB薄膜电极应用于催化各种卤代乙酸的电还原, 估计并比较了它们的表观催化反应速率常数。     

酞菁镍-表面活性剂薄膜修饰电极及其催化性能的研究

将酞菁镍(NiPc)掺入阳离子表面活性剂双十二烷基二甲基溴化铵(DDAB)的氯仿溶液中,并涂布于热解石墨电极表面,待氯仿挥发后制得NiPc-DDAB薄膜电极。循环伏安实验表明,在KBr溶液中,该薄膜电极有两对良好且稳定的还原氧化峰,第一对峰的E_pc1=-0.64V,E_pa1=-0.60V(vs.SCE);第二对峰的E_pc2=-0.84V,E_pa2=-0.80V,本文着重探讨了第二对峰的电化学行为,估计了该体系的电化学参数如电子扩散系数De和非均相电极反应速率常数k^0'.该薄膜电极可用于催化各种卤代乙酸的电化学还原,用多种表面分析技术对该薄膜进行了表征。     

一氯乙酸和三氯乙酸在富勒烯/DDAB膜修饰电极上的电催化

研究了由阳离子表面活性剂双十二烷基二甲基溴化铵分别和C60或C70在玻碳电极表面形成的膜在0．5mol／L KCl溶液中的电化学,发现在0～-1．0V范围内,有两对峰形较好的还原再氧化峰。实验结果表明,该修饰电极有较好的稳定性和重现性,对三氯乙酸和一氯乙酸的还原,表现出良好的电催化去卤化作用,说明修饰电极上的富勒烯是良好的电子传递媒介体。     

Effective enhancement of peroxydisulfate electrochemiluminescence on C60/DDAB films

Effective enhancement of electrochemiluminescence (ECL) of peroxydisulfate on a C₆₀/didodecyldimethyl ammonium bromide (C₆₀/DDAB) film coated glassy carbon electrode (GCE) surface is reported in this paper. The C₆₀/DDAB film gave lower cathodic current in the presence of peroxydisulfate than that from a bare GCE. To our surprise, electrochemiluminescent intensity from peroxydisulfate reduction was effectively enhanced on the C₆₀/DDAB film, which was 50 times and 250 times higher than those from a DDAB film coated and bare GCE, respectively. Moreover, the ECL onset potential on the C₆₀/DDAB film was about −0.9 V, which positively shifted 200 mV compared with that from the bare GCE. Dissolved oxygen and the applied potential also affected the electrochemiluminescent intensity. The presence of oxygen decreased the intensity, and the intensity reached maximum at the applied potential of −1.7 V. The unique property will greatly enrich ECL studies and applications based on fullerenes.     

Electrocatalysis of nitric oxide reduction by hemoglobin entrapped in surfactant films

We have investigated the electrochemical reduction of NO catalyzed by hemoglobin, HbFe, trapped within a dimethyldidodecylammonium bromide (DDAB) film cast on a glassy carbon electrode. The presence of NO in the electrolyte drastically changes the voltammetric response of the DDAB/HbFe film. Two reduction waves, with intensity proportional to NO concentration, are observed at −0.6 and −1.0 V versus SCE, respectively. The reduction wave at −1.0 V is a mass-transport controlled one. The typical voltammetric behavior of HbFe is discussed in terms of reactivity of the iron-heme enzyme toward NO, giving ferrous nitrosyl and nitroxyl adducts.     

辣根过氧化物酶在表面活性剂膜中的直接电化学

利用3种表面活性剂分别将辣根过氧化氢酶固定在裂解石墨棱面（edge-plane pyrolytic graphite,EPG)电极表面,研究了辣根过氧化物酶（HRP）中Fe(Ⅲ）／Fe（Ⅱ）电对与电极之间的直接电子传递过程以及酶催化双氧化还原过程。实验结果表明：（1）表面活性剂是一种固定酶的理想材料;（2）这种体系可能构造第三代生物传感器,对解释生物体代谢过程具有理论意义,对制备第三代生物传感器具有应用价值。     

Spectroscopic and Electrochemical Characterization of Cytochrome P450st‐DDAB Films on a Plastic‐Formed Carbon Electrode

We have studied the characterization of thermophilic cytochrome P450 (P450st)‐didodecyldimethylammonium bromide (DDAB) films by using UV‐vis absorption, resonance Raman spectroscopy, and electrochemical methods. The observed Raman spectrum indicated near‐native conformation of the heme iron in DDAB film on the surface of a glass slide, while on the surface of a plastic‐formed carbon (PFC) electrode, the conformation of P450st‐DDAB was very similar to that of heme‐DDAB film, suggesting the release of heme from P450st in DDAB films on PFC electrodes. When NaBr was added as salt to the casting solution, the result of Raman spectrum indicated near‐native conformation of P450st in DDAB film even on the PFC electrode, but no redox potential of P450st which has near native structure was observed. This study suggests the essential experimental conditions when working with heme protein‐DDAB films as, in some cases, heme iron from proteins is released on the surface of the electrode.     

An electroreflectance approach to study out the puzzling state of myoglobin in a DDAB film on a pyrolytic graphite electrode surface

The state of the heme of myoglobin molecules incorporated in a didodecyldimethylammonium bromide (DDAB) film on a pyrolytic graphite electrode was described using the results of electroreflectance measurements. It was found that the hemes are released from the myoglobin molecules. The ER spectrum of PG electrode|Mb–DDAB film was indistinguishable from the spectrum of PG electrode|hemin–DDAB film, even in the presence of NaBr, but clearly different from PG electrode|imidazole-coordinated hemin–DDAB. These results support the claim of de Groot and coworker [M.T. de Groot, M. Merksx, M.T.M. Koper, J. Am. Chem. Soc. 127 (2005) 16224; M.T. de Groot, M. Merkx, M.T.M. Koper, Electrochem. Commun. 8 (2006) 999]. It is likely that DDAB is not a strong inhibitor of imidazole coordination but acts on the protein, resulting in conformational change and the heme release.     

Analysis of haloacetic acid mixtures by HPLC using an electrochemical detector coated with a surfactant-nafion film

High pressure liquid chromatography (HPLC) using an electrochemical (EC) detector electrode of pyrolytic graphite coated with a film of ionomer Nafion and the water-insoluble surfactant didodecyldimethylammonium bromide (DDAB) was used to achieve separation and detection of all six bromo- and chloro-acetic acids. The Nafion-DDAB film preconcentrates the acid anions facilitating their electrochemical detection by direct reduction at -1.2 V versus SCE. Detection limits were poorer than the EPA-approved GC-ECD method, but HPLC-EC avoids the derivatization necessary for GC. The HPLC-EC method also detected tribromoacetic acid, which has not been determined simultaneously with other halogenated acids by reported chromatographic methods. The HPLC-EC method using a Nafion-DDAB-coated detector electrode gave comparable results to GC-ECD for the determination of TCA in drinking water.