The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 22 3 2022 11 22 Design & construction of a tapered optical fiber sensor for the detection of streptavidin protein Design & construction of a tapered optical fiber sensor for the detection of streptavidin protein 193 198 3304 10.47176/ijpr.22.3.51454 FA Bahareh Mazlum Dizaji School of Physics, Iran University of Science and Technology, Tehran, Iran Mohammad Vahedi School of Physics, Iran University of Science and Technology, Tehran, Iran Ali Maleki Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran Hossein Saghafifar Optics & Laser Science and Technology Research Center, Malek Ashtar University of Technology, Isfahan, Iran Journal Article 2022 05 16 This paper presents the fabrication process and operation of a bio-sensor based on tapered optical fiber by using optical spectrum shift in the presence of PBS buffer and dissolved streptavidin. The taper-fiber sensors are 18 and 24 μm in diameter and are fabricated by use of an oxy-butane torch. The optical spectrum is obtained using a broadband light source and an optical spectrum analyzer (OSA) in a 40 nm wavelength range. The existence of streptavidin on the tapered fiber surface is confirmed. The experiments on PBS buffer have shown that, the output spectrum demonstrates a red-shift by adding the streptavidin. The maximum sensitivity obtained is 29000 nm/RIU. This paper presents the fabrication process and operation of a bio-sensor based on tapered optical fiber by using optical spectrum shift in the presence of PBS buffer and dissolved streptavidin. The taper-fiber sensors are 18 and 24 μm in diameter and are fabricated by use of an oxy-butane torch. The optical spectrum is obtained using a broadband light source and an optical spectrum analyzer (OSA) in a 40 nm wavelength range. The existence of streptavidin on the tapered fiber surface is confirmed. The experiments on PBS buffer have shown that, the output spectrum demonstrates a red-shift by adding the streptavidin. The maximum sensitivity obtained is 29000 nm/RIU. https://ijpr.iut.ac.ir/article_3304_0e9d935f7e3f2b502450c049ddbc7c92.pdf