Tapered photonic crystal fibers coated with ultra-thin films for highly sensitive bio-chemical sensing

• Main Authors: Vladimir P. Minkovich, Alexander B. Sotsky
• Format: Article
• Language: English
• Published: SpringerOpen 2019-05-01
• Series: Journal of the European Optical Society-Rapid Publications
• Subjects: Optical fiber devices; Optical fiber sensors; Optical fiber interferometer; Photonic crystal fibers
• Online Access: http://link.springer.com/article/10.1186/s41476-019-0103-6

Abstract Background Photonic crystal fiber Mach-Zehnder modal interferometers based on no adiabatic tapered fibers are perspective for bio-chemical sensing, since they have very high refractive index sensitivity and it is possible for them to use a very small quantity of investigated samples. To obtain a desirable sensitivity to a needed analyte, it was proposed to coat a sensing surface of the refractive index sensor with ultra-thin films. Methods In this work, we reported on a no adiabatic tapered special photonic crystal fiber coated with an ultra-thin layer of a Bovine Serum Albumin (BSA) antigen or with an 8 nm palladium film to detect interaction between the BSA antigen and an anti-BSA antibody or for fast detection of hydrogen concentrations, respectively. Results and conclusion During our experiments, we received a record detection limit of 125 pg/ml of the anti-BSA antibody concentration. Fast detection of hydrogen concentrations up to 5.6 vol% was carried out. By using a proposed electrodynamics model of a hydrogen sensor, an optimal taper sensing length was determined.