MEMO: A micro memo sensor detecting microRNA-RISC using an accurate cell-free expression platform

Abstract

Circulating microRNAs have emerged as potential prognostic biomarkers of various diseases. They serve as micro memos sent out by cells, which scientists can intercept to gain real-time insights into cellular and disease status. However, establishing a standardized microRNA detection platform remains a challenge. Here, we integrate the RNA-induced silencing complex (RISC), which occupies mature microRNAs, into a complex cell-free synthetic genetic circuit using three different RNA polymerases, creating an innovative microRNA biosensor that is sensitive, precise, and cost-effective. The RISC protects the microRNA degradation during isolation and ensures the elimination of false target interactions, enhancing the detection robustness. With a limit of detection of 81 pM, affordability, and the possibility for on-demand use, this system proves to be a strong miRNA sensing tool.