Colorimetric miRNA detection based on self-primer-initiated CRISPR-Cas12a-assisted amplification

Method summaryThe method is constructed by integrating self-primer-assisted chain extension, a CRISPR-Cas12a-system-based chain cleavage and functionalized gold nanoparticle-based color generation. Taking advantage of multiple signal amplification processes, the method exhibits high sensitivity. miRNAs alter significantly throughout pregnancy to support the development of the fetus. However, sensitive detection of miRNA remains a challenge. Herein, a reliable miRNA detection approach integrating self-assembly-triggered signal amplification and CRISPR-Cas12a-system cleavage-based color generation is described. The colorimetric approach contains three signal amplification processes. The first signal amplification is formed by the released miRNA in a chain extension process. The produced sequence that is similar to the target miRNA initiates the second signal recycle. Finally, CRISPR-Cas12a-based transcleavage on linker sequences induces the third signal amplification. The method exhibits high sensitivity and a low limit of detection of 254 aM, showing promising prospects in disease diagnosis.