A programmable and sensitive CRISPR/Cas12a-based MicroRNA detection platform combined with hybridization chain reaction

MicroRNAs (miRNAs) play an essential role in cancer diagnosis and prognosis. Developing a new method for sensitive detection of miRNA is constantly in demand. CRISPR/Cas12a system can nonspecifically cleave singlestranded DNA after specific recognition of target DNA, showing tremendous potential in molecular diagnostics. However, CRISPR-based detection methods require synthesizing different crRNAs for detecting different targets, which limit their widespread application. Herein, we design a versatile and sensitive miRNA detection platform based on CRISPR/Cas12a system combined with a hybridization chain reaction (HCR) circuit. In this design, the HCR circuit as the signal transducer converts each miRNA into multiple DNA duplexes, which act as the activators to activate the trans-cleavage activity of Cas12a for further signal amplification. More importantly, this platform can sensitively detect different miRNAs without changing the spacer sequence of crRNA due to the fixed activators formed by HCR. In addition, the consistency between the proposed platform and RT-qPCR in miRNA detection extracted from different cell lines validated its practicability, demonstrating the potential in clinical diagnosis of cancers and monitoring therapy.