title: Manometric transduction in enzyme biosensors.
abstract: The combination of enzymatic recognition and manometric transduction is explored, using enzymes that consume or evolve a gas with low solubility in aqueous media. A design is discussed whereby change in partial pressure of a gas in the headspace is related to the turnover of analyte by the enzyme. Headspace and sample volume dimensions are considered, demonstrating the influence of flux at the air-water interface. The relative importance of diffusion and reaction for the enzyme solution is shown. When enzyme kinetics dominate, the concentration gradient is low and the overall kinetics are determined by the total amount of active enzyme, reducing either enzyme concentration or enzyme layer thickness will reduce the diffusion limitation. A Teflon-enzyme composite is presented to allow a reuseable immobilised enzyme preparation and a disc with stirring magnet identified as an efficient configuration. A glucose oxidase system was tested in the monitoring of glucose consumption during fermentation. Application to other enzyme systems is discussed.
authors.affiliation: Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK.
authors.forename: Beatriz Fernandez
authors.initials: BF
authors.lastname: Serra
authors.forename: Achilles
authors.initials: A
authors.lastname: Tzoris
authors.forename: Elizabeth A H
authors.initials: EA
authors.lastname: Hall
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003627:Data Interpretation, Statistical; D004798:Enzymes; D005285:Fermentation / Q000502:physiology*; D008365:Manometry
chemical_list: D004798:Enzymes