Fiber-optic Sensor for Sodium lon Based on a Novel Fluorescent Dye Sodium Green™

  • Jose H. Bergantin Jr Chemical Sensors and Biosensors Laboratory, Research Center for the Natural Sciences, University of Santo Tomas, España, Manila
  • Fortunato Sevilla III Chemical Sensors and Biosensors Laboratory, Research Center for the Natural Sciences, University of Santo Tomas, España, Manila
Keywords: fiber-optic sensor, fluorescence, sodium ion, Sodium Green

Abstract

An optical fiber fluorescence sensor for sodium ion was developed. A dextran derivative of the fluorescent dye Sodium Green™ was covalently immobilized on a Biodyne A™ membrane disk. The disk was set at the common end of a bifurcated optical fiber and positioned in a flow cell. The leg ends of the optical fiber were coupled to the light source and detector of a fluorescence spectrophotometer via a positioner. The immobilized dye exhibited an excitation wavelength of 510 nm and an emission wavelength of 550 nm. The fluorescence signal was completely reversible and reproducible. Typical response time varied from 3 to 5 min depending on the concentration. The equilibrium sensor signal was not affected by flow rate. Calibration curves constructed for sodium ion exhibited a linear range from 5 to 40 mM (r = 0.969) and a sensitivity of 0.424 F.U./mM. Minimal interference was indicated for K+, Li+, Ca2+, and Mg2+. Acidic pH values were observed to inhibit sensor response.
How to Cite
Bergantin Jr, J. H., & Sevilla III, F. (1). Fiber-optic Sensor for Sodium lon Based on a Novel Fluorescent Dye Sodium Green™. KIMIKA, 17(2), 49-52. https://doi.org/10.26534/kimika.v17i2.49-52
Section
Research Articles