School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2013 May 15;109:110-5. doi: 10.1016/j.saa.2013.02.017. Epub 2013 Feb 21.
A novel electrogenerated chemiluminescence (ECL) assay for sensitive determination of thrombin is designed employing CdSe/ZnS quantum dots served as an ECL label. This ECL sensor is fabricated on graphene modified glassy carbon electrode which is then covered with a low surface coverage of gold nanoparticles (AuNPs). An aptamer is used to selectively recognize the target. The thiol-terminated aptamer is first immobilized on AuNPs/graphene modified electrode, and then thrombin is imported to form the aptamer-thrombin complexes. After blocking the nonspecifically bound oligonucleotides with MCH solution, another CdSe/ZnS quantum dots modified aptamer is hybridized with the free thiol-terminated aptamer to form a DNA complexe. A decreased ECL signal is observed upon recognition of the target thrombin. The integrated ECL intensity versus the concentration of thrombin is linear in the range from 0.01 to 50 nM. The detection limit is 10 fM. The present aptasensor also exhibits excellent selectivity, stability and reusability. This sensing system can provide a promising label-free model for aptamer-based compounds sensitive detection.
一种新型的电致化学发光（ECL）分析方法被设计用于灵敏检测凝血酶，该方法采用 CdSe/ZnS 量子点作为 ECL 标记物。该 ECL 传感器是在修饰有石墨烯的玻碳电极上制备的，然后在其表面覆盖低表面覆盖率的金纳米粒子（AuNPs）。采用适体来选择性地识别目标。巯基末端的适体首先固定在 AuNPs/石墨烯修饰电极上，然后引入凝血酶以形成适体-凝血酶复合物。用 MCH 溶液封闭非特异性结合的寡核苷酸后，另一个 CdSe/ZnS 量子点修饰的适体与游离的巯基末端适体杂交形成 DNA 复合物。在识别目标凝血酶时，观察到 ECL 信号降低。整合的 ECL 强度与凝血酶的浓度在 0.01 到 50 nM 的范围内呈线性关系。检测限为 10 fM。该适体传感器还表现出优异的选择性、稳定性和可重复性。该传感系统为基于适体的化合物的灵敏检测提供了一种有前景的无标记模型。
