Chitosan catalyzes hydrogen evolution at mercury electrodes
In recent decades chitosan has attracted great attention as biodegradable biomaterial with interesting properties, making chitosan useful in biomedicine and various fields of practical life. Chitosan was generally considered as an electrochemically inactive polysaccharide. Here we show that chitosan (containing glucosamine residues) produced voltammetric and chronopotentiometric reduction peaks at mercury and solid amalgam electrodes in a wide pH range. These peaks strongly increased with the buffer concentration and with decreasing pH and were assigned to the catalytic hydrogen evolution reaction. Under the same conditions chitin oligomers (containing N-acetylated glucosamines) displayed no significant electroactivity. Polyanionic polymers, such as DNA and hyaluronic acid, formed multilayers with the adsorbed chitosan. (C) 2014 Elsevier B.V. All rights reserved.