Sensitive detection of mRNA is key in molecular cancer diagnostics. Current mRNA detection is based on next generation RNA sequencing or PCR involving multiple processing steps. However, these techniques are either time consuming or demand expensive instrumentation. Building on fruitful Phase 2 collaborations that led to the development of optical DNA origami biosensors for microRNA detection and the detection of circulating tumor cells (CTCs) by SERS, the team of this project seeks in Phase 3 to design new DNA origami-based sensors for the ultra-sensitive detection of mRNA in bulk solutions and in single cells including circulating immune cells. To this end, the team combines complementary expertise in oncology, biomarker discovery, DNA nanotechnology and nanophotonics.