Colorimetric path tagging of filaments using DNA-based metafluorophores

Abstract

The idea is a nanoscale extension of a sporting event called a `color run'. The filament is wrapped with a DNA origami `barrel', which acts as the nanoscale equivalent of a white t-shirt. The DNA t-shirt has dangling ss-DNA `handles' that bind `tags' consisting of an `anti-handle' oligo bound to a fluorophore. The tagging methodology exploits the recent development of DNA-based `metafluorophores' with digitally tunable optical properties based on a collection of fluorophores bound to a single DNA origami structure. In this idea, the filament collects different color tags at `color-stations' as it travels through the network. These contribute to a final DNA t-shirt color that represents of the path taken. Readout is implemented through lenseless on-chip imaging via pixels in a CMOS backplane located at read-out points in the network. Color-stations are implemented via microfluidic channels on a dialysis membrane, which feed tags into the network in localised areas. A chemical countermeasure to prevent false tagging by stray tags that have drifted in from other stations by exploiting strand-displacement technique is also proposed.