College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, 250014, China.
College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, 250014, China.
Biosens Bioelectron. 2020 Jun 1;157:112177. doi: 10.1016/j.bios.2020.112177. Epub 2020 Mar 26.
MicroRNAs are essential post-transcriptional regulators and may act as the noninvasive biomarkers for disease diagnosis. Sensitive and multiplexed detection of microRNAs may facilitate the accurate and early clinical diagnosis, but the available methods are usually compromised by using organic dyes as the signal probes, laborious chemical and enzymatic manipulations, and the complicated reaction schemes. Here we reported a siRNA-directed self-assembled quantum dot (QD) biosensor for facile and simultaneous detection of multiple microRNAs. In this biosensor, the binding of microRNA targets with corresponding QD nanoprobes leads to the formation of siRNA duplexes, which not only induces the spectrally resolved coding of microRNAs, but also facilitates the assembly of QDs:magnetic nanoparticle bioconjugates for the isolation and enrichment of target microRNAs. The disassembled QDs can be sensitively detected by single-molecule detection, enabling quantitatively sensing of microRNAs at the single-particle level. This biosensor employs only QDs as the signal reporters, which can simultaneously detect multiple microRNAs from the same sample and achieves femtomolar sensitivity and single-base mismatch selectivity without the involvement of any target labeling and amplification steps. Moreover, it can be successfully applied for simultaneous detection of circulating microRNAs in clinical serum samples, holding great potential in non-invasive early diagnosis and biomedical researches.
微小 RNA 是重要的转录后调控因子，可作为疾病诊断的非侵入性生物标志物。敏感且多重检测微小 RNA 可促进准确和早期的临床诊断，但现有的方法通常受到以下因素的限制：使用有机染料作为信号探针、繁琐的化学和酶处理以及复杂的反应方案。在这里，我们报道了一种基于 siRNA 指导的自组装量子点 (QD) 生物传感器，用于简便且同时检测多种微小 RNA。在该生物传感器中，微小 RNA 靶标与相应的 QD 纳米探针的结合导致 siRNA 双链体的形成，这不仅诱导微小 RNA 的光谱分辨编码，而且还促进 QD：磁性纳米颗粒生物缀合物的组装，用于靶微小 RNA 的分离和富集。解组装的 QD 可以通过单分子检测进行灵敏检测，从而能够在单颗粒水平上定量检测微小 RNA。该生物传感器仅使用 QD 作为信号报告器，可同时从同一样本中检测多种微小 RNA，实现了飞摩尔灵敏度和单碱基错配选择性，而无需涉及任何目标标记和扩增步骤。此外，它还可以成功应用于临床血清样本中循环微小 RNA 的同时检测，在非侵入性早期诊断和生物医学研究中具有巨大潜力。
