Chemiluorescent optical fiber immunosensor for on-site bioaerosol monitoring system

In this work, we describe an optical iber immunosensor for on-site bioaerosol monitoring application. Considering its integration to the monitoring system, a polymethyl methacrylate (PMMA) iber was used as a sensor probe. The iber edge surface was modiied with a layer-by-layer (LbL) assembled ilm for immobilizing primary antibodies. The LbL ilm was formed by depositing alternating layers of cationic and anionic polymers, namely, poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA), respectively. To assess the sensor performance, a model immunoassay experiment was conducted with mouse (mIgG) and horseradish peroxidase (HRP)-labeled anti-mouse (a-mIgG) antibodies. mIgG was immobilized on PAAs in the LbL ilm. After afinity binding of HRP-labeled a-mIgG to mIgG, a solution containing a luorescent substrate, 10-acetyl-3,7-dihydroxy-phenoxazine (ADHP), is added. The resultant luorescent product, resoruin, is then excited with light of 570 nm wavelength from the iber edge, and the emitted luorescence of 600 nm wavelength is collected by an identical iber edge and detected by a photomultiplier tube. As results of the experiment, a sensor limit of detection (LOD) of 85 ng·mL^-1 and a dynamic range of 0.71-100 μg·mL^-1 for a-mIgG were determined. It was demonstrated that the optical iber immunosensor has superiority in size and lexibility with high sensor performance, and thus can be easily incorporated into a monitoring system.