Publication

Feedback mode SECM study of laccase and bilirubin oxidase immobilised in a sol-gel processed silicate film

Author(s): Nogala, Wojciech and Szot, Katarzyna and Burchardt, Malte and Roelfs, Folkert and Rogalski, Jerzy and Opallo, Marcin and Wittstock, Gunther
Title: Feedback mode SECM study of laccase and bilirubin oxidase immobilised in a sol-gel processed silicate film
Abstract: Thin silicate films with immobilised enzymes catalysing dioxygen i.e. laccase and bilirubin oxidase (BOD), were deposited on and poly(methyl 2-methylpropenoate) (Plexiglas (R)) surfaces in a process by sol drop evaporation. Scanning electrochemical (SECM) images and approach curves were recorded using as mediator in the feedback mode. Confocal laser microscopy (CLSM) images in the reflection mode showed larger thickness close to the edge of the film and laccase aggregates the film. SECM images obtained using different dioxygen showed that the film edge and laccase aggregates exhibit enzymatic activity towards dioxygen reduction. SECM curves enabled the determination of kinetic information the particular regions of the samples after numerical fitting of parameters. The heterogeneous first order rate constant at the border was estimated to be ca. 19 times higher than the value when approaching to the centre of the film. The reason of laccase surface concentration at the film edge is carefully For comparison of laccase and BOD activities, silicate spots 50 mu m diameter were deposited on a single Plexiglas (R) sample and using SECM. BOD exhibits much higher activity especially at neutral pH.
Pages: 2051-2058
Journal: ANALYST
Publisher: ROYAL SOC CHEMISTRY
Addres: THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND
Volume: 135
ID: ISI:000280087000029
Year: 2010
DOI: 10.1039/c0an00068j