Department of Gynecology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian 350005, China.
Department of Gynecology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China.
Anal Methods. 2024 Jun 6;16(22):3577-3586. doi: 10.1039/d4ay00561a.
Analysis of exosomes provides important information for rapid and non-invasive screening of tumors. However, sensitive and convenient detection of exosomes remains technically challenging to date. Herein, a colorimetric aptasensor based on the light-stimulated oxidase-mimicking activity of FITC was constructed for detecting ovarian cancer (OC) exosomes. The aptasensor contained an EpCAM aptamer to capture OC exosomes. Cholesterol and fluorescein (FITC) were used to modify either end of the DNA (DNA anchor). The DNA anchor could combine with exosomes through a hydrophobic reaction between cholesterol and the lipid membrane. FITC oxidized 3,3',5,5'-tetramethylbenzidine (TMB) under a 365 nm LED light source in a temporally controllable manner under mild conditions, causing the solution to change from colorless to blue, and the corresponding UV-vis absorbance increased. Based on this principle, the exosomes were qualitatively analyzed by observing the color change with the naked eye. In parallel, the exosome concentration was also detected using UV-vis spectrophotometry. The linear range was from 2 × 10 to 100 × 10 particles per mL with a limit of detection of 1.77 × 10 particles per mL. The developed aptasensor also exhibited favorable selectivity and could discriminate the exosomes from OC cells and normal cells. Besides, the receiver operating characteristic (ROC) curve demonstrates that it is possible to distinguish between patients with OC and healthy donors (HDs) using exosomes as the biomarker. Our technology may expand the applications of DNA-based detection method-enabled OC diagnostic tools.
分析外泌体为快速、非侵入性的肿瘤筛查提供了重要信息。然而，迄今为止，外泌体的敏感、便捷检测仍然具有技术挑战性。在此，我们构建了一种基于 FITC 光刺激酶模拟活性的比色适体传感器，用于检测卵巢癌（OC）外泌体。该适体传感器包含 EpCAM 适体以捕获 OC 外泌体。胆固醇和荧光素（FITC）分别用于修饰 DNA（DNA 接头）的两端。DNA 接头可以通过胆固醇与脂质膜之间的疏水反应与外泌体结合。在 365nm LED 光源的刺激下，FITC 可以在温和条件下以时间可控的方式氧化 3,3',5,5'-四甲基联苯胺（TMB），使溶液从无色变为蓝色，相应的紫外-可见吸收增加。基于这一原理，通过肉眼观察颜色变化可以对外泌体进行定性分析。同时，也可以通过紫外-可见分光光度法检测外泌体的浓度。线性范围为 2×10 至 100×10 个颗粒/mL，检测限为 1.77×10 个颗粒/mL。所开发的适体传感器还表现出良好的选择性，可以区分 OC 细胞和正常细胞的外泌体。此外，受试者工作特征（ROC）曲线表明，使用外泌体作为生物标志物，可以区分 OC 患者和健康供体（HDs）。我们的技术可能会扩展基于 DNA 的检测方法在 OC 诊断工具中的应用。
