Assembly of β-glucosidase multilayers on spherical colloidal particles and their use as active catalysts

beta-glucosidase (beta-GLS) layers of the enzyme, each separated by oppositely charged polyelectrolyte (poly(styrenesulfonate), PSS), were deposited onto polystyrene (PS) latex particles using the layer-by-layer adsorption technique. Electrophoretic mobility (EPM) and single-particle light scattering (SPLS) measurements revealed regular and step-wise assembly of beta-GLS/PSS multilayers on the colloidal particles. Alternating positive and negative zeta-potentials were observed for beta-GLS and PSS deposition, respectively. An average thickness of 3.5 +/- 0.6 nm was calculated for each beta-GLS/PSS layer pair from SPLS data. The immobilized catalyst (in the form of an enzyme multilayer film on particles) proved to be active in the glucosidation of dodecanol, yielding dodecyl-beta-D-glucopyranoside. The product yield increased with increasing enzyme layer number for beta-GLS multilayer-coated PS particles when the outermost layer was polyelectrolyte. (C) 2000 Elsevier Science B.V. All rights reserved.