Yeast-modified electrodes as amperometric biosensors for glycerophosphate

Abstract

Several strains of baker’s and wine yeast Saccharomyces cerevisiae and yeast Kluyveromyces lactis were screened for possible sources of the enzyme L-glycero­phosphate oxidase in whole cell amperometric biosensors for glycerophosphate. The sensitivity of a yeast-modified carbon paste electrode to glycerophosphate depended on the yeast sample, the mediator and the mode of electrode preparation. Potassium hexacyanoferrate (III) was found to be the most suitable mediator in terms of electrode sensitivity and stability. The best biosensor was based on commercially available baker’s yeast. The detection limit of such electrodes was in the range 33 to 48 μM of D,L-glycerophosphate. The response was linear in the concentration range from 0 to 2.4 mM.