CONICET | Buscador de Institutos y Recursos Humanos

An amperometric electrode for oxalate determination immobilizing the oxalate oxidase in a mucin/chitosan (muc/chit) gel with glutaraldehyde as crosslinking agent is presented. The effect of muc/chit weight ratio and volumepercent (vol.%) of glutaraldehyde was studied. A very low dynamic response was observed in the case of 100%chitosan with 5 vol.% crosslinking agent. The addition of mucin to chitosan for enzyme immobilization resulted in abiosensor with much better performance, concerning to dynamic response, sensitivity, and stability, with 75% of theinitial response after two months. The ratio muc/chit 70/30 was considered optimum for the immobilization. A slightcrosslinking and the incorporation of mucin largely influences the swelling and diffusion of the analyte; a direct effectof these properties on the calibration slope was found; the hydrophilic environment for the biomolecule also favor theenzymatic activity through a higher enzyme-substrate interaction.