Biofilms on electrodes and crosslinking of bovine pericardium tissue : application to biopower device development and anti-calcification of bioprosthetic valves

Advances in the electrical communications between enzymes and electrodes made it possible to the fabrication of new miniaturized implantable power devices. This thesis is devoted to study and improvement of enzyme electrodes by integration of enzymes and redox mediators capable of transferring electrons between enzymes and electrodes with a view to developing a semi- or fully implantable, miniature, membrane-less enzymatic fuel cell (EFC) exploiting enzymatic oxidation of glucose coupled to the enzymatic reduction of dissolved dioxygen. Miniaturisation is possible if appropriate enzymes are selected as catalysts, instead of nonselective precious metal catalysts, by removal of ion-exchange membrane from assembled fuel cells. The immobilisation chemistry of enzymes and redox complexes capable of shuttling electrons between enzymes and electrode surface can have an impact on the magnitude and stability of current response, with implications for application as biosensor and EFC development. Enzyme electrode prepared using co-immobilisation of redox mediators, multiwalled carbon nanotube and polymer support using a chemical crosslinker provide 3dimensional biofilms for an electrocatalytic response for substrate, such as sugar, important in biosensor and biofuel cell applications. The objective of this thesis was to investigate the interactions of redox complexes, enzyme and nanostructure on electrode surface for application to developing a semi-or fully implantable, membrane-less EFC anode for energy generation. Furthermore, the optimisation of the electrochemical response of enzyme electrode was evaluated using a design of experiment approaches, in seeking to improve the current density under physiological conditions. Moreover as a part of the research programme, an industrial secondement project was undertaken in Boston Scientific Galway (BSG). The project involved development of a bio-reactor that can be used to simulate calcification of bovine pericardium in vitro and its application to study cross-linkers to attempt to inhibit calcification. The application of cross-linking chemicals to inhibit the calcification rates is a link to enzyme electrode modification for biosensor and biofuel cell application. A second, academic, secondement was conducted in Lund University under the supervision of Prof. Lo Gorton focused on a comparison of cross-linking reaction conditions for preparation of films of redox polymers, enzymes and supports on electrodes for application as biofuel cell anodes.

Funder

Marie Curie Initial Training Network – BIOENERGY

Rights

Attribution-NonCommercial-NoDerivs 3.0 Ireland

cbn

Collections

University of Galway Theses (PhD Theses)