Increasing density of antibody-antigen binding on a sensor surface by controlling microfluidic environments

Antibody-antigen reactions are widely used in biological detection. Researchers typically use either optical or electrical measurements to examine the sensing surface for specific antigens. Poor antibody-antigen density results in poor sensitivity of biological detection. The purpose of this research is to enhance antibody-antigen density on sensing surfaces by controlling the microenvironment. Vortices of samples were produced according to the structure and conditions of the microenvironment. Finite element analysis was used to compute the velocity field, streamline, and vorticity of samples in the microenvironment. Fluorescent particles were used to show streamline of samples experimentally. Experimental results were compared to simulated ones. Finally, Turnip Yellow Mosaic Virus (TYMV) was used as the specific antigen in the experiment. Experiment results showed that the density of TYMV detected by vortex microenvironment was 16.5 times greater than the density detected by a dipping method. The duration of experiment by vortex microenvironment was 2.3×10^-4 times less than the duration by dipping method. This research offers a simple and efficient design that benefits rapid and real-time detection.