Droplet flow focusing for molecular binding detection

Abstract

We report the detection of interfacial molecular binding via droplet generation in a flow focusing device. DNA hybridization at the phospholipid causes interfacial tension shift at the oil-water boundary which changes the mode of droplet production in the device. Droplet size decreased ~30% due to a complementary binding compared with non-complementary and control cases. Our report includes a molecular protocol to functionalize the interface with single-strand (ss) DNA as receptor and flow condition tuning for an unambiguous distinction of complementary binding.