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

A selection of recently available catalytic carbon powders were assess ed and compared with the more conventionally used platinized material. Their suitability for incorporation in amperometric biosensors is dis cussed, In conjunction with this study, methods of applying membranes to the surfaces of these devices were investigated. Advanced fabricati on technologies, potentially suitable for scale-up of sensor productio n, such as screen printing and ink-jet printing, were used for manufac ture of the complete sensor structure. Hydrogen peroxide-sensing elect rodes and glucose biosensors were produced as model systems, demonstra ting the advantages of these approaches. The commercially available rh odinized carbon MCA4 produced a high current density at low potentials over a plateau region (300-400 mV vs SCE). In addition, direct oxidat ion of glucose (seen with platinized carbon) was not observed at the c hosen potential of +350 mV. Further interference studies using ferment ation media highlighted its suitability as an electrode material for u se in complex samples. Ink-jet printing proved to be a successful meth od for the deposition of Nafion membranes of defined and reproducible geometry.