基于金属有机骨架材料固载的碲化镉量子点作为信号探针测定心肌肌钙蛋白的电致化学发光免疫传感器

An ECL immunesensor based on metal organic frameworks carried CdTe quantum dots as the signal probe for cardiac troponin I detection

该研究基于金属有机骨架材料(MOFs)固载的碲化镉量子点(CdTe QDs)作为信号探针构建了电致化学发光(ECL)免疫传感器用于心肌肌钙蛋白I(cTnI)的检测。具体来讲,在合成MOFs过程中加入CdTe QDs,制得CdTe@MOFs,随后利用CdTe@MOFs外面的氨基与CdTe QDs的羧基交联,制备出CdTe@MOFs/CdTe QDs复合物,再利用该复合物中CdTe QDs剩余的羧基与二抗(Ab_2)中氨基交联,从而制备出CdTe@MOFs/CdTe QDs/Ab_2生物探针。电极敏感界面的构建是首先在裸玻碳电极上修饰一层金纳米颗粒,来固载cTnI的第一抗体(Ab_1),再用BSA封闭其非特异性结合位点,从而制得了ECL免疫传感器。基于夹心型反应模式,此免疫传感器实现了对cTnI的灵敏检测且线性响应达8个数量级(1.1 fg/mL至11 ng/mL)。

In this work, an electrogenerated chemiluminescence（ECL） immunesensor was developed using metal organic frameworks（MOFs） carried CdTe quantum dots（CdTe QDs） as the signal probe for cardiac troponin I（cTnI）detection. Firstly, the as-prepared CdTe QDs were added during the synthesis of MOFs to form the CdTe@MOFs.Then, the CdTe@MOFs were further used as carriers to immobilize the CdTe QDs with the aid of EDC and NHS as coupling agents to form CdTe@MOFs/CdTe QDs nanocomposites. Subsequently, the resultant nanocomposites of CdTe@MOFs/CdTe QDs were served as tracing tags for assembling Ab_2 to obtain the signal probes of CdTe@MOFs/CdTe QDs/Ab2（Ab2bioconjugates）. Meanwhile, the Au nanopaticles were first modified onto the surface of a glassy carbon electrode（GCE） for sensing interface construction, which afforded a large surface area formassive Ab1 anchoring via Au-S or Au-N bonding. Based on the ＂sandwich reaction＂ strategy, this immunesensor provided an ultrasensitive ECL detection of cTnI with a linear response about 8 orders of magnitude（from 1.1 fg/m L to 11 ng/m L）.