The Structure of Layer-by-Layer Self-Assembled Glucose Oxidase and Os(Bpy)2ClPyCH2NH-Poly(allylamine) Multilayers: Ellipsometric and Quartz Crystal Microbalance Studies

ERICA S. FORZANI; MARCELO OTERO; MANUEL A. PÉREZ; MANUEL LÓPEZ TEIJELO; ERNESTO J. CALVO

LANGMUIR

AMER CHEMICAL SOC

Año: 2002 vol. 18 p. 4020 - 4020

0743-7463

p style="MARGIN: 0cm 0cm 0pt; mso-layout-grid-align: none" class="MsoNormal">Self-assembled multilayers composed of alternated layers of glucose oxidase (GOx) and poly(allylamine) covalently attached to [Os(bpy)2ClPyCOH]+ (PAH-Os), deposited on a 3-mercaptopropanesulfonic acid (MPS)-modified gold surface were studied ?ex situ? and ?in situ? (with the films in contact with water) by ellipsometry and quartz crystal microbalance (QCM). The ellipsometric parameters of the thiol film on gold in the first layer were analyzed in terms of an anisotropic single-layer model. For the subsequent (PAHOs) n(GOx)n multilayers on Au, a two-layer model with the anisotropic thiol film and the isotropic enzyme/polyelectrolyte film yielded identical results with an isotropic one-layer model with the substrate parameters measured after thiol adsorption to offset any effect due to the Au-S bond. Film thickness and complex refractive index for each adsorbed layer in Au/MPS/(PAH-Os)n(GOx