As the emerging and noninvasive biomarkers, exosomes play an important role in cancer screening, cancer-related immune response, and the physiological process. The sensitive, specific, and efficient detection of cancer cell-derived exosomes is of significance for early cancer diagnosis of patients. This work developed a novel dual-signal and intrinsic self-calibration aptasensor of exosomes based on a functional hybrid thin-film platform. This platform was constructed via facile assembly of black phosphorus nanosheets (BPNSs) and ferrocene (Fc)-doped metal-organic frameworks (ZIF-67) on indium tin oxide (ITO) slice, followed by combining methylene blue (MB)-labeled single- strand DNA aptamer on ITO slice. The resultant aptamer-BPNSs/Fc/ZIF-67/ITO platform had dual redox-signal responses of MB (labeled on aptamer) and Fc (doped into ZIF-67). In the presence of specific cancer cell-derived exosomes, the redox current of MB regularly reduced and that of Fc (as reference) hardly changed. An intrinsic self-calibration aptasensor was achieved and enabled sensitive detection of exosomes, showing a limit of detection down to 100 particles mL-1. The aptasensor with a capability of precise protein capture can efficiently determine specific cancer cell-derived exosomes in practical human serum and plasma samples from healthy individuals and breast cancer patients. In light of excellent performances, this aptasensor can be expanded to multiple biomarkers from cell line exosomes and is beneficial for exploring advanced techniques for high-performance detection of exosomes derived from different types of cancer cells. This work promotes the development of current techniques for early cancer screening and clinical diagnosis.

中文翻译：

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黑色磷纳米片和MOF的组装，形成功能性混合薄膜，用于精确的蛋白质捕获，特定癌症衍生的外来体的双信号和内在自校准传感。

作为新兴的非侵入性生物标志物，外来体在癌症筛查，癌症相关的免疫反应和生理过程中起着重要作用。癌细胞衍生的外来体的灵敏，特异性和有效检测对于患者的早期癌症诊断具有重要意义。这项工作开发了一种新的基于功能性混合薄膜平台的外泌体双信号和内在自校准自适应传感器。该平台是通过在铟锡氧化物（ITO）片上方便地组装黑磷纳米片（BPNS）和掺杂二茂铁（Fc）的金属有机骨架（ZIF-67），然后结合亚甲基蓝（MB）标记的单个-在ITO切片上束缚DNA适体。所得的适体-BPNSs / Fc / ZIF-67 / ITO平台具有MB（在适体上标记）和Fc（掺入ZIF-67）中的双重氧化还原信号响应。在特定癌细胞衍生的外来体存在下，MB的氧化还原电流有规律地降低，而Fc（作为参考）的氧化还原电流几乎不变。实现了内在的自校准适体传感器，并实现了外泌体的灵敏检测，显示了检测限低至100个颗粒mL-1。具有精确蛋白质捕获能力的适体传感器可以有效地确定健康人和乳腺癌患者的实际人血清和血浆样品中特定的癌细胞衍生外泌体。鉴于其出色的性能，该适体传感器可以从细胞系外泌体扩展到多种生物标志物，并且对于探索用于高性能检测来自不同类型癌细胞的外泌体的先进技术很有帮助。