TY  - GEN
A1  - Hofmann, Tobias Wolfgang
N2  - Droplet-based micro?uidics offers tremendous capabilities for high-throughput-screening systems, but so far, the dearth of appropriate analytical assays has limited
its widespread application.
Here, we present a novel, label-free sensor method for the detection of biochemical reactions inside of micron-sized droplets. The method exploits the osmotically driven
change in droplet size as a quantitative marker of the total osmolarity. Changes in osmolarity, which originate, for example, from the metabolic activity of cells, can be
detected down to a few mOsm/l.
We characterize the sensor system by investigating mixtures of two types of monodisperse aqueous droplets in oil, containing various, ?xed amounts of solute. Differing
concentrations of solute induce water ?ow between the droplets through the oil, compensating for the osmotic pressure until equilibrium is reached. The ?ux is mediated
by the diffusion of reverse micelles and increases with increasing differences in solute concentration.
We apply the method to monitor and quantify the metabolic activity of encapsulated yeast at the single cell level and demonstrate its use for live/dead assays.
Due to its simple and broadly applicable principle, our novel sensor method provides a powerful analytical tool for screening applications, and advances the evolution of
high-throughput-screening systems with droplet-micro?uidics.
KW  - microfluidics
KW  -  droplet
KW  -  osmosis
AV  - public
Y1  - 2013/02/28/
TI  - Applying microdroplets as label-free sensors for reactions inside the droplets
ID  - heidok14644
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/14644/
ER  -