Parallel measurements of reaction kinetics using ultralow-volumes.
We present a new platform for the production and manipulation of microfluidic droplets in view of measuring the evolution of a chemical reaction. Contrary to existing approaches, our device uses gradients of confinement to produce a single drop on demand and guide it to a pre-determined location. In this way, two nanoliter drops containing different reagents can be placed in contact and merged together, in order to trigger a chemical reaction. The reaction rate is extracted from an analysis of the observed reaction-diffusion front. We show that the results obtained using this platform are in excellent agreement with stopped-flow measurements, while decreasing the sample consumption 5000 fold. We also show how the device operation can be parallelized in order to react an initial sample with a range of compounds or concentrations, on a single integrated chip. This integrated chip thus further reduces sample consumption while reducing the time required for the experimental runs from hours to minutes.
Laboratoire d'Hydrodynamique (LadHyX) and Department of Mechanics, Ecole Polytechnique, CNRS, 91128, Palaiseau, France. baroud@ladhyx.polytechnique.fr.
Etienne
E
Fradet
Paul
P
Abbyad
Marten H
MH
Vos
Charles N
CN
Baroud
D015086:2,6-Dichloroindophenol / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry; D004058:Diffusion; D007700:Kinetics; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D009821:Oils / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry
D009821:Oils; D011092:Polyethylene Glycols; D015086:2,6-Dichloroindophenol; D001205:Ascorbic Acid