NASICON-BASED SOLID-ELECTROLYTE CELL AS TRANSDUCER FOR ENZYME SENSORS

Enzyme sensors for glucose and uric acid have been developed based on a solid-electrolyte cell using NASICON (Na3Zr2Si2PO12). These potentio metric devices respond reversibly to glucose and uric acid over a conc entration range of two orders of magnitude with sensitivities of - 54 and - 52 mV/decade, respectively. The sensors can be used for a batch- type as well as a flow-through-type measuring system. Primarily the se nsors respond to the H2O2 that is produced by the enzymatic reactions. The role of the three-phase region, electrolyte solution, sensing ele ctrode metal and NASICON has been investigated. The liquid electrolyte /sensing electrode metal interface is found to work as a potential-det ermining as well as a rate-determining interface for the enzyme sensor .