Characterization of a novel micro fluidic approach for increased sensitivity of sensors measuring surface reactions

A novel micro fluidic approach was developed and characterized in a mathematical and experimental way. It consists of a flat channel leading above the gold surface, whereas a second flow can vertically be injected, shortly before the main channel reaches the gold. This second flow, here termed as supporting flow, is analyt free and inert. It has to focus the main stream on the side of the channel where the wall reaction takes place. This simple technique reduces the vertical diffusion path of the analyt to the ligand. As the diffusion also takes place in the opposite direction, which is negative according reaction performance, the conditions have to be analyzed, which make it reasonable to use this method. Based on a mathematical model for micro reactors with a catalytic wall reaction on one side of a channel, an analytical solution for parabolic velocity profiles was developed. With use of this solution a novel micro fluidic approach for increased sensitivity of sensors measuring surface reactions was characterized. Hence, appropriate parameters were determined and experimentally proved.