Queensland Micro-and Nanotechnology Centre (QMNC), Griffith University, Nathan Campus, Nathan, QLD 4111, Australia.
School of Engineering and Build Environment (EBE), Griffith University, Nathan Campus, Nathan, QLD 4111, Australia.
Analyst. 2022 Aug 8;147(16):3732-3740. doi: 10.1039/d2an00875k.
Exosomes are vesicles released by healthy and cancer cells into the extracellular matrix and bodily fluid. Cancer cell-derived exosomes have attracted much attention in early-stage detection and prognostication of treatment response. Thus, detecting exosomes is of great interest to biology and medicine. However, many conventional detection methods require high-cost equipment and centralized laboratory facilities, making diagnostics inaccessible in limited-resource settings. This study reports a proof-of-concept low-cost electrochemical paper-based analytical device to quantify both the total bulk and cancer cell-derived exosomes in cell culture media. The device employs a sandwich immune assay design, where exosomes are initially captured using the electrode-bound generic antibodies ( CD9) and subsequently detected ovarian cancer-specific CA125 antibodies. Our proposed device quantifies the total bulk exosome concentration with a detection limit of 9.3 × 10 exosomes per mL and ovarian cancer cell-derived exosomes with a detection limit of 7.1 × 10 exosomes per mL, with a relative standard deviation of <10% ( = 3). We suggest that this low-cost and simple electrochemical paper-based device could be an alternative tool for detecting disease-specific exosomes in biological samples with the potential to be further developed for point-of-care diagnosis.
外泌体是健康细胞和癌细胞释放到细胞外基质和体液中的囊泡。癌细胞来源的外泌体在治疗反应的早期检测和预后判断中引起了广泛关注。因此，对外泌体的检测引起了生物学和医学领域的极大兴趣。然而，许多传统的检测方法需要昂贵的设备和集中的实验室设施，使得在资源有限的环境中无法进行诊断。本研究报告了一种概念验证的低成本电化学纸基分析装置，用于定量检测细胞培养介质中的总外泌体和癌细胞来源的外泌体。该装置采用三明治免疫分析设计，首先使用电极结合的通用抗体（CD9）捕获外泌体，然后用卵巢癌特异性 CA125 抗体检测。我们提出的装置定量检测总外泌体浓度的检测限为 9.3×10 个外泌体/mL，检测卵巢癌细胞来源的外泌体的检测限为 7.1×10 个外泌体/mL，相对标准偏差<10%（n=3）。我们认为，这种低成本、简单的电化学纸基装置可以作为检测生物样本中疾病特异性外泌体的替代工具，并有潜力进一步开发用于即时诊断。
