Authors: P. Pham, J.L. Achard , J. Berthier and F. Ginot
Affilation: CEA-LETI, France
Pages: 202 - 205
Keywords: droplet, Marangoni convection, binding, OGN
Binding of targetted biomolecules, pathogens or analytes on a reactive surface is commonly used for biodiagnostic systems. However the process is slow and inefficient if one relies only on molecular diffusion to transfer the analytes to the immobilized ligand. A micropump based on a Marangoni convection in a droplet geometry has been designed in order to enhance the kinetics of binding. The droplet is suspended to a heated rod and cooled at its bottom, resulting in a gradient of temperature on the liquid-air interface that drives a Marangoni convection inside the droplet. This type of convection has been verified by an experimental set up. We have then developped a numerical model for the calculation of the kinetics of binding: first, a calculation of the Maragoni flow is performed assuming a steady state convection, second, we solve a coupled system for the the concentration of analytes inside the droplet and the adsorption at the wall. The model shows the efficiency of the convection on the kinectics of capture of the anlaytes.