Critical comparison of metallized and mediator-based carbon paste glucose biosensors

The performance of metallized carbon oxidase-based biosensors is critically compared with that of mediator-based enzyme electrodes. Dimethyl ferrocene and rhodium metal centers are used as model mediator and catalyst, respectively, in connection to carbon-paste electrode transducers and assays of glucose. The rhodium-containing bioelectrode displays enhanced selectivity (particularly improved discrimination against ascorbic acid), lower sensitivity, faster response time, greater oxygen dependence, and similar detection limit in comparison to the mediated electrode. In addition to assessing the relative merits of both strategies, the data offer useful insights into the behavior of these ‘first’- and ‘second-generation’ oxidase amperometric electrodes.