在这里，我们提出了一种用于构建超敏感的外泌体miRNA检测生物传感器的方案。我们描述了制备石墨烯量子点 - 磷酸二酰胺基甲磺酸酯型寡核苷酸杂合物、沉积至还原石墨烯氧化物场表面、使分析物miRNA与传感器探针杂交，以及捕获和计算电信号的步骤。我们还详细介绍了优化生物传感器构建和评估性能的程序。通过量化血浆外泌体miRNA21，该方案可以将癌症患者与健康个体区分开来。有关使用和执行该方案的详细信息，请参阅Li等人1。版权©2023作者。由Elsevier Inc.出版。保留所有权利。

Here, we present a protocol for constructing an ultrasensitive biosensor for exosomal-miRNA detection. We describe steps for preparing graphene quantum dot-phosphorodiamidate morpholino oligomer hybrids, depositing them onto the reduced graphene oxide field surface, hybridizing analyte miRNA with the sensor probe, and capturing and calculating electrical signals. We also detail procedures for optimizing biosensor construction and evaluating performance. By quantifying plasma exosomal miRNA21, this protocol can identify cancer patients from healthy individuals. For complete details on the use and execution of this protocol, please refer to Li et al.1.Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.