Evaluation of different fluorocarbon oils for their internal oxygen supply in glucose microsensors operated under oxygen-deficit conditions Original Research Article

Several fluorocarbon oils have been assessed and compared as an internal source of oxygen in connection to their use as binders for carbon-paste glucose biosensors. All four polychlorotrifluoroethylene oils tested dramatically increase the oxygen capacity of carbon-paste enzyme electrodes to allow convenient biosensing under severe oxygen-deficit conditions. The ability to address the oxygen demand depends upon the length of the chlorotrifluoroethylene polymer. The effects of the binder upon the redox activity of the liberated hydrogen peroxide, and on the sensor linearity and sensitivity are examined. A needle-type device, integrating the oxygen-rich enzyme electrode with the reference electrode, offers convenient glucose monitoring in oxygen-free solutions. On-line continuous testing of the needle biosensor indicates favorable dynamic properties with no carry-over effects over the physiological and pathophysiological range (2–15 mM glucose). Such attention to the oxygen demand should improve the reliability of devices for in vivo monitoring of glucose.