School of Food Science and Technology, Henan Key Laboratory of Cereal and Oil Food Safety Inspection and Control, Henan University of Technology, Lianhua Road 100#, Zhengzhou High & New Technology Industries Development Zone, Zhengzhou, 450001, Henan Province, People's Republic of China.
Mikrochim Acta. 2018 Jun 28;185(7):344. doi: 10.1007/s00604-018-2872-9.
Graphene oxide doped with nitrogen and sulfur was decorated with gold nanoparticles (AuNP-SN-GO) and applied as a substrate to modify a glassy carbon electrode (GCE). An aptamer against the model protein thrombin was self-assembled on the modified GCE which then was exposed to thrombin. Following aptamer-thrombin interaction, biotin-labeled DNA and aptamer 2 are immobilized on another AuNP-SN-GO hybrid and then are reacted with the thrombin/AuNP-SN-GO/GCE to form a sandwich. The enzyme label horseradish peroxidase (HRP) was then attached to the electrode by biotin-avidin interaction. HRP catalyzes the oxidation of hydroquinone by hydrogen peroxide. This generates a strong electrochemical signal that increases linearly with the logarithm of thrombin concentration in the range from 1.0 × 10 M to 1.0 × 10 M with a detection limit of 2.5 × 10 M (S/N = 3). The assay is highly selective. It provides a promising strategy for signal amplification. In our perception, it has a large potential for sensitive and selective detection of analytes for which appropriate aptamers are available. Graphic abstract A sandwich-type electrochemical aptasensor is fabricated for detection of thrombin using a glassy carbon electrode modified with nitrogen- and sulfur-doped graphene oxide and gold nanoparticles.
氮硫共掺杂氧化石墨烯负载金纳米粒子（AuNP-SN-GO）被修饰到玻碳电极（GCE）上。将针对模型蛋白凝血酶的适体自组装到修饰后的 GCE 上，然后暴露于凝血酶。在适体-凝血酶相互作用之后，生物素标记的 DNA 和适体 2 固定在另一个 AuNP-SN-GO 杂化体上，然后与凝血酶/AuNP-SN-GO/GCE 反应形成三明治结构。然后，通过生物素-亲和素相互作用将酶标记辣根过氧化物酶（HRP）连接到电极上。HRP 催化过氧化氢对氢醌的氧化。这会产生一个强的电化学信号，该信号与凝血酶浓度的对数呈线性增加，在 1.0×10−7 M 至 1.0×10−5 M 的范围内检测限为 2.5×10−7 M（S/N=3）。该测定法具有高度选择性。它为信号放大提供了一种很有前途的策略。在我们看来，它具有很大的潜力，可用于对具有合适适体的分析物进行灵敏和选择性检测。
