Application of optical fiber biosensor in quantitative detection of HER3 antibody

In order to realize the real-time, sensitively and rapid monitoring of the interactions between biomolecules, and obtain kinetic parameters of biomolecules existence, concentration and interaction, an affinity detection method based on fiber biosensor is designed in this paper. Firstly, a coupling structure between a self-focusing lens and a quartz fiber is proposed for the coupling problem between the optical transmission system "Y"-type bifurcated optical fiber and the fiber probe in the optical interference bio-affinity sensing system. The coupling structure has an eccentricity tolerance of up to 0.02 mm, and a tilt tolerance of 0.1°. In order to solve the problem of high frequency noise of the interference spectrum, an improved EMD interference spectral signal processing method is adopted to effectively avoid the deviation of the extreme point position after filtering of interference spectral curves; at the same time, method for calculating the thickness of biomolecule film layer by using locally fitted extreme points is adopted to increase the resolution of the biofilm layer thickness to 50 pm. Using the established light interference bio-affinity detection system, a new method for the detection of concentrations of HER3-IgG1 antibody using gold nanoparticles for signal amplification was established. There was no need for cleaning and no cross-contamination will occur during the detection process. The experimental results show that the detection limit of the system reaches 0.0826μg/ml. Due to the advantages of short detection time, accurate measurement, high precision, and low cost, the system is suitable for the study of pharmacokinetics.