CATALYTIC MATERIALS, MEMBRANES, AND FABRICATION TECHNOLOGIES SUITABLE FOR THE CONSTRUCTION OF AMPEROMETRIC BIOSENSORS

A selection of recently available catalytic carbon powders were assessed and compared with the more conventionally used platinized material. Their suitability for incorporation in amperometric biosensors is discussed, In conjunction with this study, methods of applying membranes to the surfaces of these devices were investigated. Advanced fabrication technologies, potentially suitable for scale-up of sensor production, such as screen printing and ink-jet printing, were used for manufacture of the complete sensor structure. Hydrogen peroxide-sensing electrodes and glucose biosensors were produced as model systems, demonstrating the advantages of these approaches. The commercially available rhodinized carbon MCA4 produced a high current density at low potentials over a plateau region (300-400 mV vs SCE). In addition, direct oxidation of glucose (seen with platinized carbon) was not observed at the chosen potential of +350 mV. Further interference studies using fermentation media highlighted its suitability as an electrode material for use in complex samples. Ink-jet printing proved to be a successful method for the deposition of Nafion membranes of defined and reproducible geometry.