Department of Chemistry, Beijing Key Laboratory for Analytical Methods and Instrumentation, Kay Lab of Bioorganic Phosphorus Chemistry and Chemical Biology of Ministry of Education, Tsinghua University, Beijing 100084, China.
Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, China.
Anal Chem. 2020 Apr 7;92(7):5546-5553. doi: 10.1021/acs.analchem.0c00469. Epub 2020 Mar 24.
In this work, an ultrasensitive electrogenerated chemiluminescence (ECL) biosensor for exosomes and their surface proteins was developed by the in situ formation of gold nanoparticles (AuNPs) decorated TiC MXenes hybrid with aptamer modification (AuNPs-MXenes-Apt). In this strategy, the exosomes were efficiently captured on an exosome recognized CD63 aptamer modified electrode interface. Meanwhile, in situ formation of gold nanoparticles on single layer TiCMXenes with aptamer (MXenes-Apt) modification was obtained, in which MXenes acted as both reductants and stabilizer, and no additional reductant and stabilizer involved. The in situ formed AuNPs-MXenes-Apt hybrid not only presented highly efficient recognition of exosomes specifically, but also provide naked catalytic surface with high electrocatalytic activity of gold nanoparticles with predominated (111) facets that significantly improved the ECL signal of luminol. In this way, a highly sensitive ECL biosensor for exosomes detection was constructed ascribing to the synergistic effects of large surface area, excellent conductivity, and catalytic effects of the AuNPs-MXenes-Apt. The detection limit is 30 particles μL for exosomes derived from HeLa cell line, which was over 1000 times lower than that of conventional ELISA method and the linear range was from 10 particles μL to 10 particles μL. This ECL sensing platform possessed high selectivity toward exosomes and their surface proteins derived different kinds of tumor cell lines (HeLa cells, OVCAR cells and HepG2 cells), and enabled sensitive and accurate detection of exosomes from human serum, which implied that the ECL biosensor provided a feasible, sensitive, and reliable tool for exosomes detection in exosomes-related clinical diagnostic.
在这项工作中，通过原位形成金纳米粒子（AuNPs）修饰的 TiC MXenes 杂化体与适体修饰（AuNPs-MXenes-Apt），开发了一种用于外泌体及其表面蛋白的超灵敏电致化学发光（ECL）生物传感器。在该策略中，外泌体在经外泌体识别的 CD63 适体修饰电极界面上被有效捕获。同时，在带有适体（MXenes-Apt）修饰的单层 TiCMXenes 上原位形成金纳米粒子，其中 MXenes 既作为还原剂又作为稳定剂，且不涉及额外的还原剂和稳定剂。原位形成的 AuNPs-MXenes-Apt 杂化不仅对外泌体具有高效特异性识别，而且提供了裸露的催化表面，具有高电催化活性的金纳米粒子，主要（111）晶面显著提高了鲁米诺的 ECL 信号。通过这种方式，由于 AuNPs-MXenes-Apt 的协同作用，构建了一种用于外泌体检测的高灵敏度 ECL 生物传感器，该传感器具有大表面积、优异的导电性和催化作用。外泌体的检测限低至 30 个 μL，来自 HeLa 细胞系，比传统的 ELISA 方法低 1000 多倍，线性范围为 10 个 μL 至 10 个 μL。该 ECL 传感平台对外泌体及其源自不同种类肿瘤细胞系（HeLa 细胞、OVCAR 细胞和 HepG2 细胞）的表面蛋白具有高选择性，能够灵敏、准确地检测人血清中外泌体，这表明该 ECL 生物传感器为外泌体相关临床诊断中外泌体的检测提供了一种可行、灵敏、可靠的工具。
