Physicochemical properties of a mucin/chitosan matrix used for the development of an oxalate biosensor

TOMÁS E. BENAVIDEZ; CECILIA I. ALVAREZ; ANA M. BARUZZI

SENSORS AND ACTUATORS B-CHEMICAL

ELSEVIER SCIENCE SA

Año: 2009 vol. 143 p. 660 - 665

0925-4005

Immobilization conditions of biomolecules play an important role in a biosensor performance. In thispaper the response of amperometric electrodes for oxalate is related with some physicochemical propertiesof the matrices where oxalate oxidase was immobilized. Swelling indexes, partition coefficientsand permeability of oxalate in mucin/chitosan matrices in a pH= 2.85 succinic acid solution were measured.These properties were also determined in the 70/30 mucin/chitosan matrix in solutions containingsuccinic acid and sulfate or chloride anions at the same pH value. The results indicate that the sensitivityof the biosensors is mainly determined by the swelling index of the matrix. High slopes of the calibrationcurves of the electrodes were obtained with highly swollen matrices indicating the importance of ahydrophilic environment for a good enzymatic response.