Point-of-care quantitative analysis of tracing microRNA disease-biomarkers remains a great challenge in the clinical diagnosis. In this paper, we developed a portable fluorescent lateral flow assay for ultrasensitive quantified detection of acute myocardial infarction related microRNAs in bio-samples. SiO₂@DQD (bilayer quantum dots assembly with SiO₂ core) based fluorescent lateral flow strip was fabricated as the analysis tool. In order to quantify the tracing microRNA in biosamples, a catalytic hairpin assembly and CRISPR/Cas12a cascade amplification method was performed and combined with the fabricated SiO₂@DQD lateral flow strip. Thus, our platform gathered double advantages of portability and ultrasensitive quantification. Based on our strips, target myocardial biomarker microRNA-133a can be detected with a detection limit of 0.32 fM, which was almost 1000-fold sensitive compared with previous reported microRNAs-lateral flow strips. Significantly, this portable fluorescent strip can directly detect microRNAs in serum without any pretreatment and PCR amplification steps. When spiked in serum samples, a recovery of 99.65 %-102.38 % can be obtained. Therefore, our method offers a potential tool for ultrasensitive quantification of diseases related microRNA in the point-of-care diseases diagnosis field.

追踪 microRNA 疾病生物标志物的即时定量分析仍然是临床诊断中的巨大挑战。在本文中，我们开发了一种便携式荧光侧流测定法，用于对生物样本中与急性心肌梗死相关的 microRNA 进行超灵敏定量检测。制备了基于SiO ₂ @DQD（具有SiO ₂核的双层量子点组件）的荧光侧流条作为分析工具。为了定量生物样品中的示踪microRNA，进行了催化发夹组装和CRISPR/Cas12a级联扩增方法，并将其与制造的SiO ₂ @DQD侧流试纸条结合。因此，我们的平台聚集了便携性和超灵敏定量的双重优势。基于我们的试纸条，可以检测目标心肌生物标志物 microRNA-133a，检测限为 0.32 fM，与之前报道的 microRNA-侧流试纸条相比，其灵敏度几乎是 1000 倍。值得注意的是，这种便携式荧光试纸可以直接检测血清中的microRNA，无需任何预处理和PCR扩增步骤。当添加到血清样品中时，回收率可达 99.65 %-102.38 %。因此，我们的方法为即时疾病诊断领域中疾病相关 microRNA 的超灵敏定量提供了潜在的工具。