Preparation of pH sensors by covalent linkage of dye molecules to the surface of polystyrene optical fibers

Abstract
Functional Bromothymol Blue dyes containing amino groups in position 3 have been immobilized on the surface of chlorosulfonated polystyrene fibers and characterized by ESCA. Upon laser irradiation, a modified fiber has been used as an antenna fiber in a twisted pair of plastic optical fibers immersed in aqueous solutions having various pH. The light transmitted to the receiving fiber depends on pH values. This device can be used as a pH sensor.