High-sensitivity drug biosensor based on taper and offset techniques for coreless optical fiber deposited with titanium dioxide nanoparticles

Abstract

This paper designed and implemented a fiber optic biosensor to detect and measure the refractive index (RI) of different drug samples based on the offset and taper technique and enhance the sensitivity by nanoparticle material coating. This sensor was designed using a coreless fiber (CF), this optical fiber was tapered with different waist diameters, and the optimal waist diameter of 83.06 µm was achieved 291 nm/ refractive index unit (RIU), and the sensor was coated with different concentration of TiO2/PVA the optimal concentration 0.02% wt has a thickness 2.6 µm of TiO2/PVA nanoparticles and it was tested with different drug samples solution with refractive indices ranging from 1 to 1.393 and the highest sensitivity was achieved 361.11 nm/RIU. It was found that the taper and TiO2/PVA nanoparticles improved the sensitivity. This sensor can detect various refractive indices of chemicals and biochemical liquids. Advantages of the proposed sensor include high sensitivity, adaptability, enabling faster real-time measurements, ease of manufacturing and operation, compact size, lightweight design, and low cost.