Development and electrochemical characterization of functional self-assembled monolayrs

(1)合成了不同烷基链长的羟基烷硫醇（HAT）、羧基烷硫醇（CAT）和氨基烷硫醇（AAT），并将其自组装膜修饰于金电极上。还制备了具有不同侧链单元的二茂铁衍生物，用于电化学还原和氧化物种。从SAM端电荷对二茂铁二甲醇伏安响应的依赖关系出发，定量地估计了SAM端电荷对双电层电位的影响。与中性HAT修饰电极（HAT/Au）相比，AAT/Au和CAT/Au修饰电极的双电层电位分别在15 ~ 45 mV和-15 ~-45 mV范围内变化。在此基础上，利用SAM/Au作为邻苯二酚衍生物的选择性电极。(2)利用AAT氨基单元的活性，将醌衍生物固定在AAT/Au表面，并研究了其电化学响应。在萘醌的情况下，NQ和Au表面之间的电荷转移速率随AAT的烷基链长度的增加而呈指数下降。在喹啉酮的情况下，观察到与烷基链长度无关的电化学可逆响应。(3)将含有两个侧链的半胱氨酸二肽修饰在金电极上作为自组装膜，研究了共存离子对Fe（CN）_6^3伏安响应的影响。在较长侧链单层膜的情况下，伏安响应受共存离子的种类的影响很大。在侧链较短的单层膜中，共存离子类型的影响相对于侧链较长的单层膜而言较小。

(1) Hydroxylalkanetiols (HAT), carboxylalkanethiols (CAT) and aminoalkanethiols (AAT) having different alkyl chain-length were synthesized and a gold electrode was modified with the self-assembled monolayrs (SAMs) of these thiols. Ferrocene derivatives having different chargeable side chain unit were also prepared for the electrochemical reduction and oxidation species. From the dependence of the SAM terminal charges on the voltammetric response of the ferrocenedimethanol, the effect of the terminal charges on the electrical double layr potential was quantitatively estimated. As compared to the neutral HAT modified electrode (HAT/Au), it was found that the change of the double layr potential is in the ranges of 15 - 45 mV and -15 --45 mV for the AAT/Au and CAT/Au, respectively. Based on these results, SAM/Au was utilized as the selective electrode for the catechol derivatives.(2) By using the reactivity of the amino unit of the AAT,quinone derivatives were immobilized on the AAT/Au surface and its electrochemical response was studied. In the case of naphtoquinone, the chargetransfer rate between the NQ and Au surface was decreased exponentially with increasing the alkyl chain-length of the AAT.In the case of quinolinequinone, electrochemically reversible responses were observed independent of the alkyl chain-length.(3) Cysteine containing dipeptides having two side chains were modified on a gold electrode as the SAM.Then the effect of the co-existing ions on the voltammetric response of Fe (CN)_6^3 was studied. In the case of the longer side-chains monolayr, the voltammetric response was considerably affected by the kind of co-existing ion. In the case of shorter side-chains monolayr, the effect of type of co-existing ion was scare as compared to the longer side-chains monolayr.