Highly sensitive electrochemical detection of cocaine on graphene/AuNP modified electrode via catalytic redox-recycling amplification
Highly sensitive electrochemical detection of cocaine on graphene/AuNP modified electrode via catalytic redox-recycling amplification
复制标题
通过催化氧化还原-循环放大在石墨烯/AuNP修饰电极上高灵敏电化学检测可卡因
DOI：
10.1016/j.bios.2011.12.010
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发表时间：
2012-02-15
影响因子：
12.6
通讯作者：
Xiang, Yun
中科院分区：
文献类型：
--
作者：
Jiang, Bingying;Wang, Min;Xiang, Yun
我们展示了一种新的策略，通过使用两个工程适配体连接到氧化还原循环信号放大的可卡因的高灵敏度电化学检测。将石墨烯/金纳米复合材料电化学沉积在丝网印刷碳电极上以增强电子转移。可卡因主要结合适体通过硫-金相互作用自组装在电极表面。目标可卡因和生物素修饰的二级结合适体的存在导致在电极表面上形成夹心复合物。链霉亲和素缀合的碱性磷酸酶（ALP）用作标记以产生定量信号。ALP底物和共反应物NADH的加入导致在酶产物和电化学氧化的物质之间形成氧化还原循环，因此信号被显著放大。由于传感表面的有效修饰和信号放大，实现了可卡因的低纳摩尔（1 nM）检测限。因此，所提出的基于适体的夹心传感方法用于可卡因的扩增检测为其他小分子的高灵敏度测定开辟了新的机会。(C)2011爱思唯尔有限公司版权所有。
We demonstrated a new strategy for highly sensitive electrochemical detection of cocaine by using two engineered aptamers in connection to redox-recycling signal amplification. The graphene/AuNP nanocomposites were electrochemically deposited on a screen printed carbon electrode to enhance the electron transfers. The cocaine primary binding aptamers were self-assembled on the electrode surface through sulfur-Au interactions. The presence of the target cocaine and the biotin-modified secondary binding aptamers leads to the formation of sandwich complexes on the electrode surface. The streptavidin-conjugated alkaline phosphatases (ALPs) were used as labels to generate quantitative signals. The addition of the ALP substrate and the co-reactant NADH results in the formation of a redox cycle between the enzymatic product and the electrochemically oxidized species and the signal is thus significantly amplified. Because of the effective modification of the sensing surface and signal amplification, low nanomolar (1 nM) detection limit for cocaine is achieved. The proposed aptamer-based sandwich sensing approach for amplified detection of cocaine thus opens new opportunities for highly sensitive determination of other small molecules. (C) 2011 Elsevier B.V. All rights reserved.