FIBER-OPTIC CHEMICAL SENSOR USING VISIBLE SEMICONDUCTOR LASER AND PLASTICIZED POLY (VINYL CHLORIDE) MEMBRANE

Abstract

A fiber-optic chemical sensor for potassium ion is constructed using a plasticized poly(vinyl chloride) (PVC) membrane containing valinomycin. A hydrophobic fluorescent dye of oxazine 750 is covalently bound to PVC, and a fluorescence intensity from the PVC membrane is measured using a visible semiconductor laser as an exciting source. The sensor response is reversible to the potassium ion concentrations in the 10^-3-10^-1M range, and a selectivity coefficient for sodium ion is 2×10^-3. A calcium ion sensor is also constructed using ETH1001 as an ionphore. The sensor reversibly responds to calcium ion in the 10^-3-10^-1M rage, and the selectivity coefficient for sodium ion is 5×10^-4.