Investigation of Microencapsulated Laccase as Enzyme Immobilization Template for Application in Bio-fuel Cell

Abstract

The electrochemical behavior of microencapsulated laccase with a non-conductive polymer (poly(ethyleneimine), PEI) adsorbed on a glassy carbon electrode (GC) had been investigated. A K m value of 76 µM and a sensitivity of 16.6 ± 0.1 nA/µM with a response time of 7.5 s had been determined for a laccase microencapsulated with PEI that was deposited on a bare GC electrode in a McIlvaine buffer at pH = 5.75 with p-phenylenediamine (PPD). The bioelectrode has found to have a permeability, P m , of 4.9 E-4 cm s -1 for PPD and too strong interactions with 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonate) acid to observe any diffusion processes. The electrochemical and enzymatic oxidation of PPD was studied under various conditions to evaluate its reversibility and stability as a suitable redox mediator. RDE experiments showed a passivation for a glassy carbon electrode modified with empty poly(ethyleneimine) microcapsules under static conditions. Under hydrodynamic conditions however, the passivation was slowed down.

Polyethylenimine: a very useful ionic polymer in the design of immobilized enzyme biocatalysts

“…A cross-linked PEI wall was generated from an emulsion of an aqueous phase containing laccase, forming microcapsules that were later immobilized on the surface of the biosensor electrode. 281,282 The laminar jet break-up technique was used to generate PEI microcapsules for immobilization of glucose oxidase from Aspergillus niger and laccase from Trametes versicolor. 283 Later, these enzyme/PEI microcapsules were used to immobilize the enzymes in paper.…”