Design of Biomolecule Interaction Detection System Based on Fiber Biosensor

Biolayer interferometry is a non-marker technique which uses an optical interference signal to analyze and detect molecular dynamics. In order to rapidly detect biomolecule interactions and obtain kinetic parameters of biological molecules, this paper presents a molecular interaction detection system based on biofilm light interference and a fiber biosensor. The coupling structure of the self-focusing lens and the quartz fiber greatly improves the coupling efficiency between the light source and the interference light. The system uses a microprocessor as the main controller to realize data acquisition, three-dimensional transmission mechanism control and constant temperature oscillation control. Finally, we design a molecular interaction detection system and compare the results with a Hitachi 7180 biochemical analyzer to detect different concentrations of immunoglobulin IgG and protein A. The binding and dissociation reactions of the human serum immunoglobulin IgG antigen and the antigen molecule protein A biosensor are detected in real time. The experimental results show that the detection limit of the system can reach 10 μg/mL, and the repeatability CV value is less than 6%, which is close to the Hitachi 7180. However, the proposed system has the advantages of high automation, low cost and does not cause cross contamination during the detection process, so it can meet the requirements of pharmacokinetics research.