Development of redox-mediated oxysilane sol–gel biosensors on carbon-film electrode substrates

Authors

  • Rasa Pauliukaite,

    1. Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal
    Search for more papers by this author
  • Carla Gouveia-Caridade,

    1. Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal
    Search for more papers by this author
  • Hans Dieter Liess,

    1. Institut für Physik, Fakultät für Elektrotechnik, Universität der Bundeswehr München, D-85577 Neubiberg, Germany
    Search for more papers by this author
  • Christopher M. A. Brett

    Corresponding author
    1. Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal
    • Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra, Portugal
    Search for more papers by this author

Abstract

Three types of carbon-film electrodes, made from electrical resistors with 1.5-, 15-, and 140-Ω nominal resistances, were used to develop redox-mediated sol–gel biosensors, and the results were compared with those from previously investigated 2-Ω carbon-film electrodes. Two different redox mediators, copper hexacyanoferrate and poly(neutral red), were deposited onto the carbon-film electrodes, with the latter showing good electrochemical properties for electroanalytical applications, which were best on electrodes made from 15-Ω carbon-film resistors. It was not possible to deposit mediator film on the carbon-film resistor electrodes of 140-Ω nominal resistance. Glucose oxidase was immobilized on poly(neutral red) modified electrodes with sol–gel encapsulation from a mixture of 3-glycidoxypropyltrimethoxysilane and methyltrimethoxysilane precursors at a volume ratio of 2 : 1. The best sensor electrochemical properties and response to glucose in model solution were found with electrodes constructed from 15-Ω resistors, although the stability under the same conditions was better in the biosensors constructed with 2-Ω nominal resistance electrodes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Ancillary