Tumor exosomes that inherit specific molecules from their parent cells are emerging as ideal biomarkers in cancer diagnostics. Most currently available exosome isolation and detection methods are time-consuming and non-specific; thus, rapid and specific exosome detection methods are needed both clinically and in research. Here, a dual-functional platform is reported composed of reversible conjunction and “off-on” signal responses. Fe₃O₄@SiO₂@TiO₂ particles with high affinity were applied to capture exosomes, and model exosomes could be isolated from solution within 20 min with a capture efficiency of 91.5%. An “on-off” fluorescence response PSMA aptasensor was constructed with improved selectivity to detect tumor exosomes by recording the fluorescence intensity with λ_ex/em = 557/580 nm. The standard curve for detecting tumor exosomes with the aptasensor was calculated as y = 371.7x + 66.17, ranging from 0.05 to 1 × 10⁴ particles/μL, with R² = 0.9737, and a detection limit of 5 × 10² particles/μL in solution. This method was successfully applied to clinical samples, and the results showed better performance in distinguishing prostate cancer patients and healthy samples than the traditional nanoparticle-tracking analysis (NTA) method. This rapid and accurate detection method for prostate cancer may aid in rapid clinical diagnosis.

Graphical abstract

中文翻译：

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用于前列腺癌诊断的血清外泌体快速特异性检测纳米平台

从母细胞继承特定分子的肿瘤外泌体正在成为癌症诊断中的理想生物标志物。目前大多数可用的外泌体分离和检测方法耗时且非特异性；因此，临床和研究都需要快速和特异性的外泌体检测方法。在这里，报告了一个由可逆连接和“关闭”信号响应组成的双功能平台。Fe ₃ O ₄ @SiO ₂ @TiO ₂应用高亲和力颗粒捕获外泌体，模型外泌体可在 20 分钟内从溶液中分离，捕获效率为 91.5%。通过记录λ _ex/em  = 557/580 nm的荧光强度，构建了一种“开-关”荧光响应 PSMA 适体传感器，具有更高的选择性以检测肿瘤外泌体。aptasensor检测肿瘤外泌体的标准曲线计算为y  = 371.7 x  + 66.17，范围为0.05～1×10 ⁴颗粒/μL，R ²  = 0.9737，检出限为5×10 ²溶液中的颗粒/μL。该方法成功应用于临床样本，结果显示出比传统的纳米粒子追踪分析（NTA）方法在区分前列腺癌患者和健康样本方面具有更好的性能。这种快速准确的前列腺癌检测方法可能有助于快速临床诊断。

图形概要