BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea.
Biosens Bioelectron. 2011 Oct 15;28(1):454-8. doi: 10.1016/j.bios.2011.06.040. Epub 2011 Jul 6.
This paper describes a novel approach to label-free electrochemical detection of human α-thrombin in human blood serum that utilizes ferrocene-coated gold nanoparticles (Fc-AuNPs). Human α-thrombin was specifically bound by the thiolated aptamers immobilized on the electrode. Positively charged Fc-AuNPs were electrostatically bound to the negatively charged aptamers. In principle, a high current peak should be observed in the absence of interactions between the aptamers and the human α-thrombin. This behavior indicates maximum adsorption of Fc-AuNPs by the negatively charged aptamers on the electrode surface. In contrast, when the thrombin-aptamer complex is formed, a low signal is expected because of the blocking capacities of the protein, which hinders the electrostatic binding of the Fc-AuNPs. The electrochemical signal, recorded by cyclic voltammetry and differential pulse voltammetry, indicates whether interactions between aptamers and proteins have occurred. There is a good correlation between the ferrocene oxidation peak intensity readings from our thrombin sensing system and the thrombin concentration, within the range of 1.2 μM-12 pM.
本文介绍了一种新的方法，用于在人血清中无标记地电化学检测人α-凝血酶，该方法利用了巯基化适配体固定在电极上的二茂铁涂层金纳米粒子（Fc-AuNPs）。人α-凝血酶通过固定在电极上的硫醇化适配体特异性结合。带正电荷的 Fc-AuNPs 通过静电相互作用与带负电荷的适配体结合。原则上，在适配体与人类α-凝血酶之间没有相互作用的情况下，应该观察到高电流峰值。这种行为表明 Fc-AuNPs 通过电极表面带负电荷的适配体达到最大吸附。相比之下，当形成凝血酶-适配体复合物时，由于蛋白质的阻断能力，预计信号会降低，这会阻碍 Fc-AuNPs 的静电结合。通过循环伏安法和差分脉冲伏安法记录的电化学信号表明适配体与蛋白质之间是否发生了相互作用。我们的凝血酶传感系统的二茂铁氧化峰强度读数与凝血酶浓度之间存在良好的相关性，范围为 1.2 μM-12 pM。
