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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. SiO 2 @DQD (bilayer quantum dots assembly with SiO 2 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 SiO 2 @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. [Display omitted] • Ultrasensitive single-line based SERS lateral flow assay for multiple exosomal proteins analysis has been developed. • For the first time CHA and CRISPR/Cas12a strategy were combined with LFA to improve the sensitivity. • The LOD (0.3 fM) was almost 1000-fold sensitivity than the previous fluorescence strips for miRNAs. • MiRNAs can be directly detected in serum without pretreatment or PCR amplification. • This assay possesses universality for miRNAs related diseases diagnosis in clinical setting. [ABSTRACT FROM AUTHOR]