Parallel Detection of Anti-Tuberculosis Antibodies upon a Liquid Crystal-based Optical Sensor

In the present study, we developed a label-free liquid crystal (LC)-based system to simultaneously detect anti-tuberculosis (TB) antibodies against multiple antigens. Multiple TB antigens were discretely immobilized on a substrate with nano-patterns replicated from a buckled poly(dimethylsiloxane) to orient LCs uniformly. After the antibody solution was introduced to surface-immobilized antigens, non-specific antibodies did not have any effect on the orientation of LCs; however, the antigen-antibody complexes formed by specific interactions disturbed the orientation of LCs by masking the anisotropic surface topography. The orientational behavior of LCs was visualized with a polarizing optical microscope. The limit of detection was from 0.15 to 1.5 mu g/mL. With this method, antibodies in the solution of interest can be identified, which will facilitate the development of a new diagnostic approach for TB.