A Simple Two-Dimensional Convective-Diffusive Based Modelling Study of a Biosensor for Glucose Detection
Over the past decade, novel technologies for biomolecular detection of target molecules of interest have been reported. The chemical reactions that govern the kinetics of the transport of target molecules to the sensor are also of significant importance. Here we analyze how the diffusion, convection, and reaction kinetics can drive the experimental design of a simple glucose biosensor. In this work, a physically intuitive and practical understanding of analyte transport is presented by modelling and simulating a two-dimensional convective-diffusive transport phenomenon in COMSOL Multiphysics to understand the mechanism of surface capture dynamics of a biosensor under the assumption of perfect binding kinetics. The target molecule of interest is glucose. In the model, 1 mol/m3 of the glucose solution is introduced at the inlet at 1 mm/s, and the process is simulated as a stationary study. It was found that by decreasing the flow rate, a threshold exists where the detection of target molecules by the sensor is solely controlled by diffusion. Comparison of convective and diffusive fluxes of the system as well as the concentration distribution reveal that a decrease in flow rate increases diffusive transport, thus increasing the fraction of target molecules that are captured by the sensor.