Phosphate Sensitive Electrodes in Model Studies for Phosphorylation and Dephosphorylation Reactions

Abstract

Highly selective and sensitive phosphate sensors have been fabricated by constructing a solid membrane disk consisting of variable mixtures of aluminium powder (Al), aluminium phosphate (AlPO₄), and powdered copper (Cu). Both binary and ternary electrode systems were produced. The ternary membranes exhibited greater selectivity over a wide range of concentrations. The ternary electrode with the composition 25% AlPO₄, 25% Cu, and 50% Al was selected as our preferred electrode for the study. Complexation and dephosphorylation reactions of model compounds which mimic enzyme and substrates were monitored. The results showed that the complexation reactions are fast and diffusion controlled.

Keywords:

• Dephosphorylation
• Electromotive force
• Enzyme models
• Phosphate electrode
• Phosphorylation
• Solid state membrane

Acknowledgments

This work was supported in part by grants from NRF-IRDP and graduate research and fellowship funds from the Chemistry Department, University of South Africa. The ecotoxicology flag ship project in the Department of Chemistry, College of Science Engineering and Technology (CSET) is gratefully acknowledged.

Notes

^a Note that there are triplicate data for each metal to substrate experiment conducted (N = 3).

^a Note that there are triplicate data for each metal to substrate experiment conducted (N = 3).

^a Note that there are triplicate data for each metal to substrate experiment conducted (N = 3).

^a Note that there are triplicate data for each metal to substrate experiment conducted (N = 3).