- Electrochemical properties of beta-(10-phenoxazinyl) propylamine (APPX) and beta-(10-phenoxazinyl) propionic acid (PPX) have been studied in solution, and in immobilized state on gold electrodes modified with monolayers of cystamine and mercaptoundecanoic acid. A reversible diffusion-controlled process of APPX and PPX was observed at a bare gold electrode. The electrochemical conversion of both compounds at modified gold electrodes was a quasireversible diffusion-controlled process. The redox potential of immobilized APPX (443 mV) was similar to the potential in solution, while the value of the immobilized PPX was 131 mV higher than in solution. The immobilized mediators were electrocatalytically active in the fungal peroxidase-catalyzed hydrogen peroxide reduction
