title: Cyclodextrin-modified biosensors: comparision of cyclodextrin-linked ferrocenes as mediators in sol-gel and screen-printed formats for sensing acetylcholine.
abstract: This work reports the comparison of a sol-gel and a screen-printed biosensor format using new mediators and a sensitive thin-film (ref. 1: P. Kataky and D. Parker, Analyst, 1996, 121, 1829) to enhance the sensitivity and stability of biosensors. The new mediators were per-alkylated cyclodextrin linked ferrocenes and a control, ferrocene aminocarboxylic acid. The thin film comprised a cocktail with polyurethane, plasticiser, lipophilic anion and a perethylated beta-CD. The analyte targeted was acetylcholine using the established horseradish peroxidase-choline-oxidase-acetylcholine esterase relay. The screen-printed electrode format showed a marked decrease in oxidation potential, the magnitude of the shift depended on the structure of the mediator and the membrane covering. Although lower oxidation-potentials were observed with the sol-gel format sensors, their response was more akin to aqueous solution behaviour. Electrocatalytic currents were observed suggesting a highly efficient electron transfer process.
authors.affiliation: Department of Chemistry, University of Durham, UK. Ritu.Kataky@durham.ac.uk
authors.forename: R
authors.initials: R
authors.lastname: Kataky
authors.forename: R
authors.initials: R
authors.lastname: Dell
authors.forename: P K
authors.initials: PK
authors.lastname: Senanayake