Key words: Binding reaction, microfluidic systems, biosensors, finite element method, biological analytes, simulation.

Abstract: The binding reaction is a significant characteristic which is adopted in the design of biosensors. This aim of the present work is to investigate the binding reaction kinetics through a microchannel. The  diffusion boundary layer on the reaction surface of a biosensor operating in fluid environment, presents restraining effects. Therefore, it is useful to optimize several critical parameters, which affect the binding reaction such as, the length of the reaction surface, the inlet flow velocity, and the initial biological analyte concentration (e.g. molecule, protein, toxin, peptide, vitamin, sugar, metal ion…) in order to reduce the thickness of the diffusion
boundary layer. The study is performed using 2D finite element method. Then, the space-time evolution of analyte concentration (such as C-reactive protein or IgG) is simulated. The results prove that the reaction kinetic is strongly affected and hence the diffusion boundary layer is assigned by the physical and geometrical parameters of the microfluidic biosensor.