2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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TechConnect Summit
Clean Technology 2008

Assembly and characterization of layer-by-layer nanostructured colloidal enzyme microreactors

P. Pescador, E. Donath, J.L. Toca-Herrera, I. Katakis

layer-by-layer, colloids, enzymes, composites

The layer-by-layer technique is employed to assemble multilayer films of enzymes and polyelectrolytes on the surface of micrometer-size silica particles. Two different enzymes, glucose oxidase (GOx) and horseradish peroxidase (HRP), are co-immobilized together with precursor and intermediate polyelectrolyte layers. In the resulting multilayer films a sequential enzymatic reaction takes place, with the conversion of glucose to gluconic acid and hydrogen peroxide catalyzed by GOx and the subsequent reduction of hydrogen peroxide to water catalyzed by HRP. The colloids act as immobilization substrates and high surface area carriers for the creation of enzymatic microreactors. The LbL approach allows to explore the influence of different polyelectrolyte combinations on the immobilization and functionality of the enzymes for different multilayer configurations. An electrochemical functionality is added to these films with the incorporation of a redox polymer to the structure. In this way, the specific chemical events taking place at the redox centers of the enzymes are transduced into an electrical signal. The LbL-coated colloids are further embedded in a redox polymer film and immobilized on the surface of gold electrodes to create new composite colloid-polymer films, which can be successfully applied as electrochemical biosensors for the detection of glucose and hydrogen peroxide.

Nanotech 2008 Conference Program Abstract