MicroRNA are endogenous short non coding RNA strands involved in post-transcriptional regulation of gene expression, discovered around 20 years ago. MicroRNA are emerging as attractive diagnostic, prognostic or predictive biomarkers because microRNA levels are closely related to various diseases including cancers, neuronal or heart diseases or diabetes. In addition, microRNA can be detected from liquid biopsies, potentially enabling a regular follow-up of treatment efficacy, detection of relapses, early diagnostic or large scale population screening. However, the detection of blood circulating microRNA is still a challenging task as they are highly diluted. In this project, we develop a background-free isothermal amplification technique relying on a DNA-based molecular programs. These molecular programs are used to generate signal amplification, while avoiding nonspecific reactions. This approach is shown to be highly sensitive for microRNA detection and can be coupled with a microfluidic droplet format to provide absolute quantification of various targets. A strategy to enable highly multiplexed detection has also been demonstrated.
