pH-mediated charge tuning of chitosan membrane: a smart approach to control electrochemical selectivity

Abstract

Chitosan is a natural polymer derived from organic chitin with numerous properties, including the ability to form membranes. It has several amino and hydroxyl groups in its polymer chain that generate surface charge, so it can be easily modified and interact with analytes. Chitosan hydrogels with different pH values were used to modify the surface of the GCE electrode. The prepared metrics were tested in the presence of redox systems [Fe(CN)₆]^3-/4-, FcDM^0/+ and [Ru(NH₃)₆]^2+/3+, where a clear effect of electrostatic interactions was observed, confirming their charge dependence controlled by changing the pH value of the hydrogel. The current response of ascorbic acid concentration analysis highlighted the influence of the pH value of chitosan hydrogels on the electrode process.