Abstract: A sensor capsule to facilitate positioning of an analyte sensitive element such as a CO2 sensor at the end of a fiber optic probe, which discloses a dye layer defined by a dye well, fluorescent dye solution and apertures formed in a silicone sensor membrane. A TEFLON® covering membrane is positioned over the silicone membrane to retain the dye layer within the well, and perforated metal disc is positioned beneath the silicone membrane to provide support and resist swelling of the dye layer. The perforated metal disc, silicone membrane and TEFLON® membrane define a sandwich sensor structure which is positioned within an outer housing. An insert member is positioned over the sandwich sensor structure and is snap fit into outer housing to provide a sensor capsule which may be removeably positioned/replaced in association with a probe tip used for forming the fiber optic CO2 SENSOR.

Abstract: Improved methods and compositions are provided to inhibit interference from formaldehyde in polarographic analytic methods. In the enzymatic oxidation of methanol to hydrogen peroxide and formaldehyde, formaldehyde serves as an interfering agent in systems where the oxygen consumed or the hydrogen peroxide produced is polarographically measured. To inhibit this interference, an amine-containing formaldehyde scavenger is added to the test system. Preferably, the scavenger comprises a polyalkyleneimine such as polyethyleneimine having a molecular weight of between about 200-1,000,000 amu. The invention is particularly well-suited for use in polarographic analytical apparatus wherein laminated membrane type enzyme electrodes are used to perform amperometric measurement with alcohol oxidase enzyme used as the oxidoreductase enzyme.

Abstract: An enzyme electrode is disclosed for use in voltammetric systems wherein a PQQ dehydrogenase enzyme is chemically bonded to a water soluble polyvinylpyridine osmium bipyridine polymer. The enzyme and polymer are adsorbed onto the surface of the electrode with the polymer providing direct electron transfer from enzyme to electrode and vice-versa without the aid of additional mediators or electron shuttles added to the system.