Electro-oxidation of phenol on a new type of zeolite/graphite biocomposite electrode with horseradish peroxidase

A novel biocomposite electrode containing horseradish peroxidase (HRP) and zeolite co-immobilized on gelatin particles mixed with graphite was described.Comparing the composite (zeolite/graphite) and the biocomposite (gelatin/HRP/zeolite/graphite) electrodes showed that the latter presented an enhancement on the electrodes diffusion properties and, apparently, the enzyme co-immobilized with zeolite on gelatin was electro-active and functioned as mediator in the electro-oxidation of phenol.Various HRP/zeolite ratios were tested and the best result was obtained with the 1:100 mHRP/mzeo biocomposite electrode. These results confirm the existence of HRP–zeolite interactions, as previously observed in pseudo-homogeneous oxidation of phenol.

Graphical abstractA novel biocomposite electrode containing horseradish peroxidase (HRP) and zeolite co-immobilized on gelatin particles mixed with graphite was described.Comparing the composite (zeolite/graphite) and the biocomposite (gelatin/HRP/zeolite/graphite) electrodes showed that the latter presented an enhancement on the electrodes diffusion properties and, apparently, the enzyme co-immobilized with zeolite on gelatin was electro-active and functioned as mediator in the electro-oxidation of phenol.Various HRP/zeolite ratios were tested and the best result was obtained with the 1:100 mHRP/mzeo biocomposite electrode. These results confirm the existence of HRP–zeolite interactions, as previously observed in pseudo-homogeneous oxidation of phenol. Figure optionsDownload full-size imageDownload as PowerPoint slide