Highly sensitive surface plasmon resonance biosensor based on a low-index polymer optical fiber

A highly sensitive refractive index sensor based on surface plasmon resonance in a side-polished low-index polymer optical fiber is proposed for biosensing. Benefitting from the low refractive index of the fiber core, the sensitivity of the device can reach similar to 44567 nm/RIU theoretically for aqueous solutions, at the expense of a lowered upper detection limit that is down to similar to 1.340. The sensor is fabricated by coating 55-nm-thick Au-film on the polished surface of a graded-index perfluorinated polymer optical fiber. Results show that the sensor exhibits a sensitivity of similar to 22779 nm/RIU at 1.335 with a figure of merit of 61.2. When employed for glucose sensing, the sensor presents an averaged sensitivity of 24.50 nm/wt%, or 0.46 nm/mM. This device is expected to have potential applications in cost-effective bioand chemical-sensing. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement