Premium
Effect of Voltage on the Topography of Alkanethiol and Poly(amidoamine) Dendrimer Layers with Immobilized Glucose Oxidase. An Atomic Force Microscopy Study
Author(s) -
Polohová Vladimíra,
Šnejdárková Maja,
Podskočová Jarmila,
Svobodová Lenka,
Chorvát Dušan,
Hianik Tibor
Publication year - 2007
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200603736
Subject(s) - glucose oxidase , poly(amidoamine) , dendrimer , cyclic voltammetry , materials science , chemical engineering , amidoamine , surface roughness , analytical chemistry (journal) , thin film , electrode , nanotechnology , chemistry , electrochemistry , polymer chemistry , biosensor , composite material , organic chemistry , engineering
We applied atomic force microscopy (AFM) to study the surface topography of the supported thin films of various composition: hexadecanethiol (HDT), poly(amidoamine) dendrimers (PAMAM) of first generation (G1), mixture of HDT+G1, glucose oxidase (GOX) and HDT+G1+GOX layers. The AFM image of dendrimers in air revealed dome‐shaped, randomly distributed aggregates of the size from 100 to 200 nm. GOX adsorbed on the gold support also formed aggregates of the diameter between 700–900 nm and height up to 36 nm. The AFM images of the HDT+G1+GOX layer in air revealed smooth surfaces with irregular pinholes, although these were corrugated in the buffer. Application of the voltage of +670 mV to the layers during one hour resulted in significant increase of the surface root means square roughness ( R rms ). The electrical properties of G1 layers studied by cyclic voltammetry do not differ substantially from bare gold electrode, while HDT+G1 mixed layers revealed intermediate electrical properties between HDT and G1. Immobilization of GOX onto the HDT+G1 resulted further decrease of the layer permeability.