Fiber optic pH sensor based on electrostatically self-assembled polymer multilayer

• Main Author: Saranya, Navaneetham
• Other Authors: Chan Chi Chiu
• Format: Theses and Dissertations
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering::Bioengineering
• Online Access: http://hdl.handle.net/10356/68495
• Institution: Nanyang Technological University

A novel fiber optic pH sensor based on the functionalization of electrostatically self-assembled chitosan (CH) and poly(acrylic acid) (PAA) on no core fiber based multimode interference has been designed and experimentally demonstrated. The pH sensitive polymeric film, chitosan and poly(acrylic acid) was deposited on the surface of the prepared sensor by making use of the layer-by-layer (LbL) electrostatic self-assembly principle. A study of the role played by pH on the functionalized sensor was carried out. The CH/PAA film presents a variation in the refractive index by the mechanism of swelling and deswelling in solutions having different pH values. This results in the modulation of transmission wavelength of the sensor. A sensitivity of 0.7471 nm/pH was observed in the linear pH range of 3 to 7.