Department of Chemistry, Beijing Key Laboratory for Analytical Methods and Instrumentation, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology of Ministry of Education , Tsinghua University , Beijing 100084 , China.
Anal Chem. 2019 Sep 17;91(18):12100-12107. doi: 10.1021/acs.analchem.9b03427. Epub 2019 Aug 30.
Exosomes derived vesicles and their surface anchored proteins by cells are extremely vital in intercellular communication, immuno-stimulation, and so on, which are promising in potential tumor biomarkers for disease diagnosis. However, the highly sensitive detection of exosomes and their surface proteins is still challenging. Herein, we combined the g-CN conjugated polydopamine coated Galinstan liquid metal shell-core nanohybrids (g-CN@Galinstan-PDA) nanoprobes and multivalent PAMAM-AuNPs electrode interface to realize a highly sensitive detection of exosomes and their surface proteins by electrogenerated chemiluminescence (ECL) biosensor. The antibody-modified PAMAM-Au nanoparticles (NPs) electrode interface provided a multivalent recognition platform for highly effective capture of exosomes. Meanwhile, the Galinstan NPs were applied as the nanoprobe. The antibody modified g-CN@Galinstan-PDA can recognize the exosomes specifically and exhibit stable and strong ECL signals due to the excellent features of the Galinstan NPs in facilitating electron transfer and suppressing the g-CN passivation during electrochemical reduction procedures. In this way, high sensitivity for HeLa cell derived exosomes analysis was obtained with the limit of detection (LOD) of 31 particles μL. Moreover, we operated the exosomes analysis in the real samples including serum, urine, and blood, and identified the multiple biomarkers (GPC1, CD9, CEA, and AFP) on the exosome surface derived from different kinds of cell lines (HeLa cell, OVCAR-3 cell, and BT474 cell). These consequences suggest that the proposed ECL biosensor has the potential to be a powerful tool for exosomes study and clinical diagnostic as well as wearable devices.
细胞来源的外泌体及其表面锚定蛋白在细胞间通讯、免疫刺激等方面具有极其重要的作用，在外泌体作为疾病诊断的潜在肿瘤生物标志物方面具有广阔的应用前景。然而，对外泌体及其表面蛋白的高灵敏度检测仍然具有挑战性。在此，我们结合了 g-CN 修饰的聚多巴胺包覆的镓铟液态金属壳核纳米杂化材料（g-CN@Galinstan-PDA）纳米探针和多价 PAMAM-AuNPs 电极界面，实现了通过电致化学发光（ECL）生物传感器对外泌体及其表面蛋白的高灵敏度检测。经抗体修饰的 PAMAM-Au 纳米粒子（NPs）电极界面提供了一个多价识别平台，可高效捕获外泌体。同时，镓铟纳米粒子（NPs）被用作纳米探针。修饰抗体的 g-CN@Galinstan-PDA 可以特异性识别外泌体，并由于 Galinstan NPs 在促进电子转移和抑制电化学还原过程中 g-CN 钝化方面的优异特性而表现出稳定且强的 ECL 信号。通过这种方式，对 HeLa 细胞来源的外泌体分析获得了 31 个颗粒 μL 的检测限（LOD）。此外，我们在包括血清、尿液和血液在内的真实样本中进行了外泌体分析，并鉴定了来自不同细胞系（HeLa 细胞、OVCAR-3 细胞和 BT474 细胞）的外泌体表面上的多个生物标志物（GPC1、CD9、CEA 和 AFP）。这些结果表明，所提出的 ECL 生物传感器具有成为外泌体研究和临床诊断以及可穿戴设备的有力工具的潜力。
