In this work, we present a microfluidic amperometric immunosensor for cancer biomarker claudin7 (CLD7) determination in circulating extracellular vesicles (EVs) as well as its validation in colorectal cancer (CC) patients. The device is based on synthetized nanosized MIL-125-NH₂ particles, covalently anchored to the central channel of the microfluidic immunosensor. This nanomaterial was employed as efficient platform for anti-CLD7 monoclonal antibodies immobilization for specifically recognize and capture CLD7 in EVs samples. Afterwards, the amount of this trapped CLD7 was quantified by HRP-conjugated anti-CLD7-antibody. HRP reacted with its enzymatic substrate in a redox process which resulted in the appearance of a current whose magnitude was directly proportional to the level of CLD7 in the sample. This immunosensor, under optimum conditions, gave the limit of detection for CLD7 of 0.1 pg mL⁻¹, with a wide linear range from 2 to 1000 pg mL⁻¹. The results reported herein open up the use of porous open framework platforms for sensing applications for biomedicine and diagnosis.

在这项工作中，我们提出了一种微流控电流免疫传感器，用于测定循环细胞外囊泡 (EV) 中的癌症生物标志物 Claudin7 (CLD7)，并在结直肠癌 (CC) 患者中进行验证。该装置基于合成的纳米级 MIL-125-NH ₂颗粒，共价锚定到微流体免疫传感器的中央通道。这种纳米材料被用作固定抗 CLD7 单克隆抗体的有效平台，用于特异性识别和捕获 EV 样品中的 CLD7。之后，这种捕获的 CLD7 的量通过 HRP 缀合的抗 CLD7 抗体进行量化。HRP 在氧化还原过程中与其酶底物发生反应，导致出现电流，其大小与样品中 CLD7 的水平成正比。该免疫传感器在最佳条件下对 CLD7 的检测限为 0.1 pg mL ^-1，线性范围从 2 到 1000 pg mL ^-1. 本文报告的结果开启了多孔开放框架平台在生物医学和诊断传感应用中的应用。