Investigation of 12 – 15 Kev Electron Transmission Through Tapered Glass Capillaries

Glass and Ceramics - The results of experimental studies of the transmission of 12 and 15 keV electron beams through tapered glass macro-capillaries are presented. Measurements showed that there is...     

Measuring coherent peaks of polarization bremsstrahlung from relativistic electrons in polycrystalline targets in backscattering geometry

The spectra of polarization bremsstrahlung (PB) in the X-ray range induced by 7-MeV electrons in a polycrystalline copper target have been measured in the backscattering geometry for various orientations of the target relative to the electron beam. It is shown that the PB backscattering is sensitive to the texture of a target. The possibility of developing a new method based on the measurement of characteristics of the coherent PB component for the diagnostics of polycrystalline materials is considered.     

Reagentless biosensor based on glucose oxidase wired by the mediator freely diffusing in enzyme containing membrane

Wiring glucose oxidase in the membrane with an immobilized mediator is possible due to the diffusion ability of the latter, if the enzyme containing membrane is formed according to the proposed protocol, including exposing proteins to water-organic mixtures with the high content of organic solvent. In the course of the study, the new glucose oxidase mediator, unsubstituted phenothiazine, was discovered. The diffusion coefficient of the mediator in the resulting membrane is independent of the presence of enzyme. The cyclic voltammograms of the enzyme electrode after appearance of the only glucose in solution obtain a well-defined catalytic shape, which is normally observed for both the enzyme and the mediator in solution. Analytical performances of the resulting biosensor are comparable to the advanced second generation ones, which, however, require covalent linking of the mediator either to the membrane forming polymer or to the enzyme. Even without such covalent linking, the reported biosensor is characterized by an appropriate long-term operational stability allowing reagentless sensing.