Scheme 1

Schematic representation of ultra-sensitive single-cell sorting through the THE-FADS. a The MCF-7 cells were illuminated using the THE signal amplification system. The EpCAM protein was located on the membrane of MCF-7 cells. The Apt-TDNs could bind EpCAM, and then the HCR was initiated to form three dendritic DNA structures with fluorescence signal amplified, the fluorescence signal was amplified further with the Evagreen added. b The cell mixture with the target MCF-7 cells illuminated by the THE-amplification system was imported into the FADS system, and the droplets encapsulated with the MCF-7 cells were selectively sorted