Author(s)

Toru Kidosaki, Satoko Takase, Youichi Shimizu

Department of Applied Chemistry, Graduate School of Engineering, Kyushu Institute of Technology, Fukuoka, Japan.

A cobalt-iron alloy thin-film electrode-based electrochemical hydrogen-phosphate-ion sensor was prepared by electrodepositing on an Au-coated Al₂O₃ substrate from an aqueous solution of metal-salts. The use of a cobalt-iron alloy electrode greatly improved the hydrogen-ion sensor response performance, i.e., the sensor worked stably for more than 7 weeks and showed a quick response time of several seconds. Among the cobalt and iron alloy systems tested, the electrodeposited Co₅₈Fe₄₂ thin-film electrode showed the best EMF response characteristics, i.e., the sensor exhibited a linear potentiometric response to hydrogen-phosphate ion at the concentration range between 1.0 × 10^–5 and 1.0 × 10^–2 M with the slope of –43 mV/decade at pH 5.0 and at 30℃. A sensing mechanism of the Co-based potentiometric hydrogen-phosphate ion sensor was proposed on the basis of results of instrumental analysis.

Hydrogen-Phosphate Ion Sensor; Cobalt-Iron Alloy; Thin-Film Electrode; Electrodeposition

T. Kidosaki, S. Takase and Y. Shimizu, "Electrodeposited Cobalt-Iron Alloy Thin-Film for Potentiometric Hydrogen Phosphate-Ion Sensor," Journal of Sensor Technology, Vol. 2 No. 3, 2012, pp. 95-101. doi: 10.4236/jst.2012.23014.