Immunosensor Surface Reaction Enhancment by Applying an AC Electrotherm Flow

Immunosensors have recently benefited from integration and miniaturization in microfluidic chips. In this research, an efficient AC electrothermal flow have been employed inside a microchannel in order to provide b) circular vorticities near the immunosensor, a) mass transfer effect, c) immunosensor concentrating enhancment. Our proposed stirring effect enhances the transport of suspended antigen to the immobilized antibody and provides more binding opportunity. The governing equations for fluid motion and immunosensor concentrating process are multiphysic coupled electric field, fluid flow, temperature field, diluted species transport and also binding reactions equations. Both the paasive (without stirring flow) and active (with stirring flow) Ab-Ag binding reaction has been numerically studied by Finite-Element Method, and the sensor location is optimized. Based on the results, the AC electrothermal swirling flow (applied ac field 10 Volt and operating frequency 200 kHz) applied to the electrodes and the surface reaction increases by the factor of 10 after 5 seconds of sample loading. The system is highly efficient for high conducive fluid mediums. Results revealed that our proposed microfluidic based reaction enhancement method is of interest in high Damkohle immunoassays and low Peclet number systems