Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
Department of General Surgery, The People's Hospital of Yangzhong City, Yangzhong, Jiangsu, China.
Anal Methods. 2023 Aug 24;15(33):4194-4203. doi: 10.1039/d3ay01006f.
In this work, based on a dual signal amplification strategy of enzyme-assisted signal amplification (EASA) and catalytic hairpin assembly (CHA), combined with the magnetic attraction effect, a capillary pump-driven surface-enhanced Raman scattering (SERS) microfluidic chip (LoC-SERS) platform was developed for the sensitive detection of colorectal cancer-associated (CRC) microRNA (miRNA). During the detection process, the miRNA first undergoes an EASA reaction with hairpin DNA1 (hpDNA1) under the action of endonuclease, which generates a large amount of DNA2 cyclically. After that, DNA2 triggers the CHA reaction to proceed, which leads to the ligation of the SERS nanoprobes and the capture nanoprobes (hpDNA2-hpDNA3 complexes). Finally, as the reactant solution flows through the collection zone, the end products are magnetically attracted by the micro-magnets, generating many "hot spots" and leading to a triple amplification of the SERS signal. By quantitative analysis, the platform achieved ultra-low detection limits of miR-122 (4.26 aM) and miR-192 (4.71 aM) within a linear range of 10 aM-10 pM. In addition, the platform's results for clinical samples are highly consistent with those measured by qRT-PCR methods. Overall, the proposed LoC-SERS platform is expected to be an important tool for the early screening of CRC.
在这项工作中，我们基于酶辅助信号放大（EASA）和催化发夹组装（CHA）的双重信号放大策略，结合磁吸引效应，开发了一种毛细管泵驱动的表面增强拉曼散射（SERS）微流控芯片（LoC-SERS）平台，用于灵敏检测结直肠癌相关（CRC）microRNA（miRNA）。在检测过程中，miRNA 首先在核酸内切酶的作用下与发夹 DNA1（hpDNA1）发生 EASA 反应，从而产生大量循环的 DNA2。之后，DNA2 触发 CHA 反应进行，导致 SERS 纳米探针和捕获探针（hpDNA2-hpDNA3 复合物）的连接。最后，随着反应物溶液流过收集区，反应产物被微磁铁吸引，产生许多“热点”，从而使 SERS 信号实现三重放大。通过定量分析，该平台在 10 aM-10 pM 的线性范围内实现了 miR-122（4.26 aM）和 miR-192（4.71 aM）的超低检测限。此外，该平台对临床样本的检测结果与 qRT-PCR 方法的测量结果高度一致。总体而言，所提出的 LoC-SERS 平台有望成为 CRC 早期筛查的重要工具。
