Chiral sensing system based on the formation of diastereomeric metal complex on a homocysteine monolayer using field effect transistor
Chiral sensing system based on the formation of diastereomeric metal complex on a homocysteine monolayer using field effect transistor
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DOI：
10.1016/j.electacta.2011.02.086
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发表时间：
2011-11
影响因子：
6.6
通讯作者：
D. Yamamoto;T. Nakanishi;T. Osaka
中科院分区：
文献类型：
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作者：
D. Yamamoto;T. Nakanishi;T. Osaka
在场效应晶体管(FET)镀金栅极表面形成的L-同型半胱氨酸(L-Hcy)自组装单分子膜用于区分氨基酸对映体，其中非对映异构体金属络合物的形成是手性识别的基础。在这里，我们把注意力集中在FET响应对被分析氨基酸、参与络合物形成的中心金属离子和溶液pH的依赖上。在添加了铜(II)的L-同型半胱氨酸SAM修饰的GATE上，对丙氨酸(ALA)、苯丙氨酸和色氨酸的L对映体有显著的负场效应晶体管(FET)反应，而对天冬氨酸和天冬氨酸的FET对映体之间的差异可以忽略不计。在丙氨酸对映体选择性方面，与Co(II)、Ni(II)等金属离子相比，添加Cu(II)具有更高的选择性。此外，对于L-丙氨酸和铜(II)的加入，在pH为5.5时观察到特别强烈的负场效应晶体管响应。
A self-assembled monolayer (SAM) of l-homocysteine (l-Hcy) formed on the surface of a gold-deposited gate of a field effect transistor (FET) was used to differentiate between enantiomers of amino acids, for which the formation of diastereomeric metal complexes is fundamental for chiral discrimination. Here, we focus our attention on the dependence of the FET response on the analyte amino acids, the central metal ions involved in complex formation, and the solution pH. Using the l-Hcy SAM-modified gate with added Cu(II), notable negative FET responses were enantioselectively observed for the l-enantiomers of alanine (Ala), phenylalanine, and tryptophan, whereas differences in the FET responses between enantiomers were negligible for asparagine and aspartic acid. Regarding the enantioselectivity for Ala, the addition of Cu(II) was demonstrated to show higher selectivity as compared to other metal ions such as Co(II) and Ni(II). Moreover, for the addition of l-Ala and Cu(II), a particularly strong negative FET response was observed at pH 5.5.