Abstract：
Simultaneous, reliable, and ultra-sensitive analysis of promising miRNA biomarkers of colorectal cancer (CRC) in serum is critical for early diagnosis and prognosis of CRC. In this work, we proposed a novel 3D hierarchic assembly clusters-based SERS strategy with dual enrichment and enhancement designed for the ultrasensitive and quantitative analysis of two upregulated CRC-related miRNAs (miR-21 and miR-31). The biosensor contains the following: (1) SERS probe, Au nanocage@Au nanoparticles (AuNC@Au NPs) labeled with Raman reporters (RaRs). (2) magnetic capture unit, Ag-coated Fe3O4 magnetic nanoparticles (AgMNPs) modified with internal standard (IS). (3) signal amplify probes (SA probes) for the formation of hierarchic assembly clusters. Based on this sensing strategy, the intensity ratio IRaRs/IIS with Lg miRNAs presents a wide linear range (10 aM-100 pM) with a limit of detection of 3.46 aM for miR-21, 6.49 aM for miR-31, respectively. Moreover, the biosensor shows good specificity and anti-interference ability, and the reliability and repeatability of the strategy were then verified by practical detection of clinical serum. Finally, the biosensor can distinguish CRC cancer subjects from normal ones and guide the distinct tumor, lymph node, and metastasis (TNM) stages. Overall, benefiting from the face-to-face coupling of hierarchic assembly clusters, rapid magnetic enrichment and IS signal calibration of AgMNPs, the established biosensor achieves ultra-sensitive and simultaneous detection of dual miRNAs and opens potential avenues for prediction and staging of CRC.
摘要：
同时,可靠,和超敏感分析大肠癌（CRC）血清中有前景的miRNA生物标志物对于CRC的早期诊断和预后至关重要。在这项工作中,我们提出了一种新的基于3D分层组装簇的SERS策略,该策略具有双重富集和增强功能,旨在对两种上调的CRC相关miRNA(miR-21和miR-31)进行超灵敏和定量分析.该生物传感器包含以下内容:(1)SERS探针,用拉曼报道分子(RaRs)标记的Au纳米笼@Au纳米颗粒(AuNC@AuNPs)。(2)磁性捕获单元，用内标(IS)修饰的Ag包覆的Fe3O4磁性纳米粒子(AgMNPs)。(3)旌旗灯号放大探针(SA探针)构成分层组装簇。基于这种感知策略，IraRs/IIS与LgmiRNA的强度比呈现宽线性范围(10aM-100pM),miR-21的检测限分别为3.46aM,miR-31的检测限分别为6.49aM.此外，生物传感器具有良好的特异性和抗干扰能力,并通过临床血清的实际检测验证了该策略的可靠性和可重复性。最后,生物传感器可以区分CRC癌症受试者和正常受试者，并指导不同的肿瘤，淋巴结,和转移（TNM）分期。总的来说,受益于分层装配集群的面对面耦合，AgMNPs的快速磁富集和IS信号校准，建立的生物传感器实现了双miRNAs的超灵敏和同时检测，并为CRC的预测和分期开辟了潜在的途径。
