Shen Tong, Yu Hongwei, Xu Xin, Zhang Ze, Yang Huanzhang, Chang Dong
Medical Laboratory Department of Fudan University Pudong Medical Center, 201399, China.
Medical Laboratory Department of Fudan University Pudong Medical Center, 201399, China.
Anal Biochem. 2025 Nov;706:115948. doi: 10.1016/j.ab.2025.115948. Epub 2025 Jul 26.
The elevated expression of microRNA-21 (miRNA-21) in exosomes derived from early-stage non-small cell lung cancer (NSCLC) holds significant promise for early diagnosis. However, detecting exosomal miRNA-21 remains challenging due to its low abundance. Here, we developed an electrochemiluminescence (ECL) biosensor integrating a 3D DNA walker with rolling circle amplification (RCA) for ultrasensitive miRNA-21 detection. Gold-silver nanoclusters (AuAgNCs, Au:Ag = 4:1) served as ECL emitters, while ferrocene-modified DNA (Fc-DNA) quenched the signal ("signal-off"). Target miRNA-21 activated the 3D DNA walker, generating primers for RCA. The RCA products displaced Fc-DNA, restoring ECL ("signal-on"). The biosensor achieved a wide linear range (1 fM-1 nM) with a 0.14 fM detection limit. Critically, it distinguished NSCLC patients (n = 10) from healthy controls (n = 10) and COPD patients (n = 10) with statistical significance (P < 0.001) in clinical serum samples. Excellent stability (84 % signal retention after 25 days) and reproducibility (RSD = 3.95 %) further support its utility for early lung cancer screening.
早期非小细胞肺癌（NSCLC）来源的外泌体中微小RNA-21（miRNA-21）表达升高对早期诊断具有重要意义。然而，由于外泌体miRNA-21丰度低，检测仍具有挑战性。在此，我们开发了一种集成3D DNA步行器和滚环扩增（RCA）的电化学发光（ECL）生物传感器，用于超灵敏检测miRNA-21。金银纳米簇（AuAgNCs，Au:Ag = 4:1）作为ECL发光体，而二茂铁修饰的DNA（Fc-DNA）淬灭信号（“信号关闭”）。靶标miRNA-21激活3D DNA步行器，产生用于RCA的引物。RCA产物取代Fc-DNA，恢复ECL（“信号开启”）。该生物传感器实现了1 fM-1 nM的宽线性范围，检测限为0.14 fM。至关重要的是，它在临床血清样本中能够将NSCLC患者（n = 10）与健康对照（n = 10）和慢性阻塞性肺疾病（COPD）患者（n = 10）区分开来，具有统计学意义（P < 0.001）。出色的稳定性（25天后信号保留84%）和重现性（RSD = 3.95%）进一步支持了其在早期肺癌筛查中的实用性。
