Simple and reliable profiling of tumor-derived exosomes (TDEs) holds significant promise for the early detection of cancer. Nonetheless, this remains challenging owing to the substantial heterogeneity and low concentration of TDEs. Herein, we devised an accurate and highly sensitive electrochemical sensing strategy for TDEs simultaneously targeting exosomal mucin 1 (MUC1) and programmed cell death ligand 1 (PD-L1). This approach employs high-affinity aptamers as specific recognition elements, utilizes rolling circle amplification and DNA nanospheres as effective bridges and signal amplifiers, and leverages methylene blue (MB) and doxorubicin (DOX) as robust signal reporters. The crux of this separation- and label-free method is the specific response of MB and DOX to G-quadruplex structures and DNA nanospheres, respectively. Quantifying TDEs using this strategy enabled precise discrimination of lung cancer patients (n = 25) from healthy donors (n = 12), showing 100% specificity (12/12), 92% sensitivity (23/25), and an overall accuracy of 94.6% (35/37), with an area under the receiver operating characteristic curve (AUC) of 0.97. Furthermore, the assay results strongly correlated with findings from computerized tomography and pathological analyses. Our approach could facilitate the early diagnosis of lung cancer through TDEs-based liquid biopsy.

中文翻译：

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靶蛋白调节的 DNA 纳米机器-电活性物质复合物可实现临床外泌体的免分离电化学检测

肿瘤源性外泌体（TDE）的简单可靠的分析对于癌症的早期检测具有重要的前景。尽管如此，由于 TDE 的显着异质性和低浓度，这仍然具有挑战性。在此，我们设计了一种准确且高度灵敏的电化学传感策略，用于同时靶向外泌体粘蛋白 1 (MUC1) 和程序性细胞死亡配体 1 (PD-L1) 的 TDE。该方法采用高亲和力适体作为特异性识别元件，利用滚环扩增和 DNA 纳米球作为有效的桥和信号放大器，并利用亚甲基蓝 (MB) 和阿霉素 (DOX) 作为强大的信号报告基因。这种免分离、免标记方法的关键是 MB 和 DOX 分别对 G-四链体结构和 DNA 纳米球的特异性响应。使用这种策略量化 TDE 能够精确区分肺癌患者 (n = 25) 和健康捐赠者 (n = 12)，显示出 100% 的特异性 (12/12)、92% 的敏感性 (23/25) 和总体准确度94.6% (35/37)，受试者工作特征曲线下面积 (AUC) 为 0.97。此外，检测结果与计算机断层扫描和病理分析的结果密切相关。我们的方法可以通过基于 TDE 的液体活检促进肺癌的早期诊断。