Development and electrochemical characterization of functional self-assembled monolayrs

(1)合成了不同烷基链长的羟基烷醇（HAT）、羧基烷醇（CAT）和氨基烷醇（AAT），并用这些巯基自组装单分子膜（sam）修饰金电极。制备了具有不同带电荷侧链单元的二茂铁衍生物，并对其进行了电化学还原和氧化。从SAM终端电荷对二茂铁甲醇伏安响应的依赖性出发，定量估计了终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的双层电位变化分别在15 ~ 45mv和-15 ~ 45mv范围内。基于这些结果，SAM/Au被用作邻苯二酚衍生物的选择电极。(2)利用AAT氨基单元的反应性，将醌类衍生物固定在AAT/Au表面，研究其电化学响应。以萘醌为例，随着烷基链长度的增加，NQ和Au表面之间的电荷转移速率呈指数下降。以喹啉醌为例，观察到电化学可逆反应与烷基链长度无关。(3)在金电极上修饰含有双侧链的半胱氨酸作为SAM。然后研究了共存离子对Fe (CN)_6^3伏安响应的影响。在侧链较长的单分子膜的情况下，伏安响应很大程度上受共存离子种类的影响。在侧链较短的单分子膜中，共存离子类型的影响比侧链较长的单分子膜小。

(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.