Aptamer-based nanofilter interface for small-biomarker detection with potentiometric biosensor
Aptamer-based nanofilter interface for small-biomarker detection with potentiometric biosensor
复制标题
DOI：
10.1016/j.electacta.2020.137631
复制
发表时间：
2021-02-01
影响因子：
6.6
通讯作者：
Sakata, Toshiya
中科院分区：
文献类型：
--
作者：
Himori, Shogo;Nishitani, Shoichi;Sakata, Toshiya
在本文中，我们报告的概念，适体（AP）为基础的纳米过滤器接口的抑制生物样品中的干扰物种产生的非特异性信号。作为目标小生物分子的模型，使用涂覆有DA-Ap纳米过滤器的Au栅场效应晶体管（FET），使用L-3，4-二羟基苯丙氨酸（L-DOPA）来证明其与多巴胺（DA）的电区分，尽管它们具有相似的化学结构。采用Au栅电极以基于氧化反应评估FET对L-DOPA的电响应。特别是，所提出的纳米过滤器接口是基于固定在芳基重氮基锚单层，这是电化学接枝在Au栅电极通过重氮化学的DA-Ap层。结果，使用DA-Ap纳米过滤器涂覆的Au栅极FET，来自L-DOPA的电信号与来自浓度为1 μ M或更高的DA的电信号被清楚地区分。也就是说，DA通过形成复合物被DA-Ap纳米过滤器捕获，复合物的分子电荷被不与Au栅极表面接触的抗衡离子屏蔽，而L-DOPA到达Au栅极表面并与之发生电化学反应，产生电信号而与纳米过滤器无关。利用循环伏安法、计时库仑法、原子力显微镜和X射线光电子能谱研究了修饰在Au栅电极上的DA-Ap纳米过滤器的表面性质。基于FET生物传感器的平台与基于AP的纳米过滤器接口有助于小生物标志物的电监测，同时抑制生物样品中干扰物质的非特异性信号。(C)2020爱思唯尔有限公司保留所有权利。
In this paper, we report the concept of an aptamer (Ap)-based nanofilter interface for the suppression of nonspecific signals generated by interfering species in biological samples. As a model of the target small biomolecule, L-3,4-dihydroxyphenylalanine (L-DOPA) is used to demonstrate its electrical discrimination from dopamine (DA) despite their similar chemical structures using a DA-Ap nanofilter-coated Au gate field-effect transistor (FET). A Au gate electrode is employed to assess the electrical response of the FET to L-DOPA on the basis of oxidative reactions. In particular, the proposed nanofilter interface is based on the DA-Ap layer immobilized at the aryl-diazonium-based anchor monolayer, which is electrochemically grafted on the Au gate electrode via diazonium chemistry. As a result, the electrical signal from L-DOPA is clearly discriminated from that from DA at a concentration of 1 mu M or higher using the DA-Ap nanofilter-coated Au gate FET. That is, DA is trapped by the DA-Ap nanofilter through the formation of complexes, the molecular charges of which are shielded by counter ions that are not in contact with the Au gate surface, whereas L-DOPA reaches and electrochemically reacts with the Au gate surface, generating an electrical signal regardless of the nanofilter. The surface properties of the DA-Ap nanofilter modified on the Au gate electrode are investigated by cyclic voltammetry, chronocoulometry, atomic force microscopy, and X-ray photoelectron spectroscopy. A platform based on the FET biosensor with the Ap-based nanofilter interface contributes to the electrical monitoring of small biomarkers while suppressing the nonspecific signals of interfering species in biological samples. (C) 2020 Elsevier Ltd. All rights reserved.