IMPROVEMENTS IN THE STABILITY CHARACTERISTICS OF BIOSENSORS USING PROTEIN-POLYELECTROLYTE COMPLEXES

The formation of protein-polyelectrolyte complexes has been directly d emonstrated for several enzymes in solution including alcohol oxidase, horseradish peroxidase, lactate oxidase and glucose oxidase using aga rose gel electrophoresis. The combination of such complexes with polyh ydroxyl compounds has been found to significantly enhance the shelf-li fe of biosensors when stored in a dehydrated form, examples of lactate and malate biosensors are given. There is evidence from enzyme soluti on and immobilisation experiments that the protein-polyelectrolyte com plexes also have the ability to improve the operational stability of t he enzyme activity during catalysis. This ability may be used to produ ce biosensors having extended working lifetimes for use in analytical devices.