Rapid mixing of colliding picoliter liquid droplets delivered through-space from piezoelectric-actuated pipettes characterized by time-resolved fluorescence monitoring

摘要: Rapid mixing of aqueous solutions is a crucial first step to study the kinetics of fast biochemical reactions with high temporal resolution. Remarkable progress toward this goal has been made through the development of advanced stopped-flow mixing techniques resulting in reduced dead times, and thereby extending reaction monitoring capabilities to numerous biochemical systems. Concurrently, piezoelectric actuators for through-space liquid droplet sample delivery have also been applied in several experimental systems, providing discrete picoliter sample volume delivery and precision sample deposition onto a surface, free of confinement within microfluidic devices, tubing, or other physical constraints. Here, we characterize the inertial mixing kinetics of two aqueous droplets (130 pl) produced by piezoelectric-actuated pipettes, following droplet collision in free space and deposition on a surface in a proof of …