Mediated glucose enzyme electrodes by cross-linking films of osmium redox complexes and glucose oxidase on electrodes

Peter Ó Conghaile, Sirisha Kamireddy, Domhnall MacAodha, Paul Kavanagh, Dónal Leech*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Here, we report on a novel, versatile approach for the preparation of mediated enzyme electrodes, demonstrated using cross-linked films of glucose oxidase and a range of functionalised osmium complexes on graphite electrodes. Response of enzyme electrodes are optimised by evaluation of glucose response as a function of variation in ratios of [Os(2,2′-bipyridine) 2(4-aminomethyl pyridine)Cl]+ redox mediator, polyallylamine support and glucose oxidase enzyme cross-linked using a di-epoxide reagent in films on graphite. Lowering of the redox potential required to mediate glucose oxidation is achieved by synthesis of complexes using (4,4′-dimethyl-2,2′-bipyridine) or (4,4′-dimethoxy-2, 2′-bipyridine) as a ligand instead of (2,2′-bipyridine). Enzyme electrodes prepared using the complexes based on dimethoxy- or dimethyl-substituted bipyridines provide glucose oxidation current densities of 30 and 70 μA cm-2 at 0.2 and 0.35 V applied potential compared to 120 μA cm-2 at 0.45 V for the initial enzyme electrode, under pseudo-physiological conditions in 5 mM glucose, with stability of signals proving inadequate for long-term operation. Current output and stability may be improved by selection of alternate anchoring and cross-linking methodology, to provide enzyme electrodes capable for application to long-term glucose biosensors and anodes in enzymatic fuel cells. [Figure not available: see fulltext.]

Original languageEnglish
Pages (from-to)3807-3812
Number of pages6
JournalAnalytical and Bioanalytical Chemistry
Issue number11
Publication statusPublished - Apr 2013


  • Biosensors
  • Electrochemical sensor
  • Enzymatic fuel cell
  • Enzymes
  • Glucose oxidase
  • Osmium

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry

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