An optical fiber biosensor based on layer-by-layer electrostatic self-assembly for rapid detection of HIgG

In this paper, we designed an optical fiber biosensor for rapid detection of HIgG, which is simple, cost-effective and can be easily fabricated. The average detection time is about 20 minutes. A thin core optical fiber with a length of 2 cm was fused between two segments of single mode optical fibers. The outside surface of the thin core optical fiber was coated with the antibody using the method of layer-by-layer electrostatic self-assembly, and then was able to detect the antigen in solution. We selected Human Immunoglobulin G (HIgG) as the antigen in the experiment. The working performance of our biosensor with different layers of the electrostatic film was investigated. Best sensitivity was achieved to be 16.92 nm/(mg/mL) when the layers was five. Best limit of detection (LOD) of our biosensor was calculated to be 0.59mg/L. Besides, NaCl solution and bovine serum albumin (BSA) solution were also added during the experiments, which showed negligible wavelength shift compared with HIgG solutions. This confirmed the specificity of our biosensor. The proposed optical fiber biosensor has good application potential in other medical or biological fields.