Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, PR China; Engineering Technology Research Center for Pharmacodynamic Evaluation of Chongqing, College of Pharmacy, Chongqing Medical University, Chongqing, 400016, PR China.
Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, PR China.
Biomaterials. 2019 Sep;216:119253. doi: 10.1016/j.biomaterials.2019.119253. Epub 2019 Jun 6.
The present work described a novel sandwich-type electrochemical aptasensor for rapid and sensitive determination of Mycobacterium tuberculosis MPT64 antigen. Herein, a novel carbon nanocomposite composed of fullerene nanoparticles, nitrogen-doped carbon nanotubes and graphene oxide (CNPs-N-CNTs/GO) was facilely synthesized for the first time, which not only possessed a large specific surface area and excellent conductivity, but also exhibited outstanding inherent electroactive property, and therefore served as nanocarrier and redox nanoprobe simultaneously. Gold nanoparticles (AuNPs) was then uniformly anchored onto the surface of such nanocomposite via Au-N bonds to bind with MPT64 antigen aptamer Ⅱ (MAA Ⅱ), forming the tracer label to realize generation and amplification of electrochemical signal. Additionally, conductive polyethyleneimine (PEI)-functionalized Fe-based metal-organic framework (P-MOF) was used as a sensing platform to absorb bimetallic core-shell Au-Pt nanoparticles (Au@Pt), which could accelerate electron transfer and increase the immobilization of MPT64 antigen aptamer Ⅰ (MAA Ⅰ). After the typical sandwich-type protein-aptamer recognition, the inherent electroactivity of the tracer label was provoked by tetraoctylammonium bromide (TOAB), leading to a well-defined current response. Under the optimum condition, the proposed aptasensor showed a wide linear range for MPT64 detection from 1 fg/mL to 1 ng/mL with a limit of detection (LOD) as low as 0.33 fg/mL. More importantly, it was successfully used for MPT64 antigen detection in human serum, exhibiting a promising prospect for TB diagnosis in clinical practice.
本工作描述了一种用于快速灵敏测定结核分枝杆菌 MPT64 抗原的新型三明治型电化学适体传感器。在此，首次简便合成了一种由富勒烯纳米粒子、氮掺杂碳纳米管和氧化石墨烯（CNPs-N-CNTs/GO）组成的新型碳纳米复合材料，它不仅具有大的比表面积和优异的导电性，而且表现出出色的固有电化学活性，因此可同时作为纳米载体和氧化还原纳米探针。随后，通过 Au-N 键将金纳米粒子（AuNPs）均匀锚定在该纳米复合材料的表面上，以与 MPT64 抗原适体 Ⅱ（MAA Ⅱ）结合，形成示踪标记以实现电化学信号的产生和放大。此外，还使用导电聚乙烯亚胺（PEI）功能化的 Fe 基金属有机骨架（P-MOF）作为传感平台来吸收双金属核壳 Au-Pt 纳米粒子（Au@Pt），这可以加速电子转移并增加 MPT64 抗原适体 Ⅰ（MAA Ⅰ）的固定化。在典型的三明治型蛋白-适体识别后，通过四辛基溴化铵（TOAB）引发示踪标记的固有电化学活性，从而产生明确的电流响应。在最佳条件下，所提出的适体传感器对 MPT64 的检测表现出从 1 fg/mL 到 1 ng/mL 的宽线性范围，检测限（LOD）低至 0.33 fg/mL。更重要的是，它成功地用于人血清中 MPT64 抗原的检测，在临床实践中为结核病诊断展示了广阔的前景。
