The effect of the chitosan membrane properties on the enzyme adsorption and performance for the construction of horseradish peroxidase biosensors

The molecular weight, degree of deacetylation and the acetic acid concentration of chitosan solutions were modulated to change the structures and properties of the chitosan membranes, including chemical structures, ionic conductivity and hydrophobicity, which were analyzed by FTIR-ATR, electrochemical impedance and water contact angle measurement, respectively. Consequently, the adsorption of horseradish peroxidase (HRP, as a model) was controlled by the structural and natural changes of chitosan membranes, exhibiting different adsorbed amount and activity. A HRP-based electrode coated with the chitosan membrane was further constructed to investigate the influence of the chitosan membrane properties on the electrochemical performance. Therefore, this work offered a fundamental understanding of the control of the enzyme adsorption and performance through changing the chitosan membrane structures and properties for the more extensive applications, especially in the construction of the highly efficient bioelectrodes.