Binding reaction kinetics of analyte-ligand at the level of a sensitive membrane into a microchannel of a biosensor has been limited by the formation of the boundary diffusion layer. Therefore, the response time increases and affects the overall performance of a biosensor. In the present work, we develop an approach to engineer fluid streams into a complex configuration in order to improve the binding efficiency. We investigate numerically the flow deformations around a parallelepiped with square cross-section inside the microfluidic channel and exploit these deformations to simulate the analyte transport to the sensitive membrane and enhance both association and dissociation processes. The effect of several parameters on the binding reaction is provided such as: the obstacle location from the inlet of the microchannel, the average flow velocity, and the inlet analyte concentration. The optimal position of the obstacle is determined. An appropriate choice of the inlet flow velocity and inlet analyte concentration may reduce significantly the response time.

Microfluidic biosensors have played an important and challenging role for the rapid detection of the new severe acute respiratory syndrome coronavirus-2 (S

This paper aims to enhance the analyte transport toward the sensing area and to enhance biosensors performances. A microchannel-based flow confinement method for rapid delivery of small sample volumes to sensor surface is described. To confine the flow, a sample flow is joined with a perpendicular makeup flow and is confined into a thin layer above the reaction surface. The numerical simulation of the confinement effect on the binding reaction is performed using the finite-element method. The influence of several parameters on the binding reaction is provided, such as the average flow velocity at the inlet of the microchannel and the velocity of the confinement flow, the characteristics of the flow confinement. The numerical results reveal that the flow confinement enhances mass transport of analytes and increase its velocity. The obtained results could be exploited in flow injection experiments for low volume.