title: Enzyme-gelatin electrochemical biosensors: scaling down.
abstract: In this article we investigate the possibility of scaling down enzyme-gelatin modified electrodes by spin coating the enzyme-gelatin layer. Special attention is given to the electrochemical behavior of the selected enzymes inside the gelatin matrix. A glassy carbon electrode was used as a substrate to immobilize, in the first instance, horse heart cytochrome c (HHC) in a gelatin matrix. Both a drop dried and a spin coated layer was prepared. On scaling down, a transition from diffusion controlled reactions towards adsorption controlled reactions is observed. Compared to a drop dried electrode, a spin coated electrode showed a more stable electrochemical behavior. Next to HHC, we also incorporated catalase in a spin coated gelatin matrix immobilized on a glassy carbon electrode. By spincoating, highly uniform sub micrometer layers of biocompatible matrices can be constructed. A full electrochemical study and characterization of the modified surfaces has been carried out. It was clear that in the case of catalase, gluteraldehyde addition was needed to prevent leaking of the catalase from the gelatin matrix.
authors.affiliation: Environmental Analysis, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium. Karolien.DeWael@ua.ac.be.
authors.forename: Karolien
authors.initials: K
authors.lastname: De Wael
authors.affiliation: Environmental Analysis, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium. stijn.debelder@ua.ac.be.
authors.forename: Stijn
authors.initials: S
authors.lastname: De Belder
authors.affiliation: Environmental Analysis, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium. sanaz.pilehvar@ua.ac.be.
authors.forename: Sanaz
authors.initials: S
authors.lastname: Pilehvar
authors.affiliation: Centre for Microsystems Technology, Department of Electronics and Information Systems, Ghent University-imec, Technologiepark 914A, B-9052 Ghent, Belgium. geert.vansteenberge@elis.ugent.be.
authors.forename: Geert
authors.initials: G
authors.lastname: Van Steenberge
authors.affiliation: Environmental Analysis, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium. wouter.herrebout@ua.ac.be.
authors.forename: Wouter
authors.initials: W
authors.lastname: Herrebout
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, NL-2333 CC Leiden, The Netherlands. h.a.heering@chem.leidenuniv.nl.
authors.forename: Hendrik A
authors.initials: HA
authors.lastname: Heering