Stimuli-Responsive Biointerface Based on Polymer Brushes for Glucose Detection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Processo FAPESP: 10/07478-5

The construction and characterization of a biosensor based on polymer brushes is reported. The use of polymer brushes combined with nanoparticles was applied to show its suitability as a biosensor platform - with glucose oxidase as an enzyme probe. The biosensor demonstrated a pH-sensitive on-off property, and it was further used to control or modulate the electrochemical responses. In terms of the kinetic behavior, we were able to show the changing in the kinetic parameters of glucose oxidase operating in on and off state of the polymer brushes. The performance of the bioelectrode was investigated by chronoamperometry, impedance electrochemistry and cyclic voltammetric techniques. At optimized experimental conditions the dynamic concentration range was 2.0 to 16.0mmolL(-1) with a detection limit of 5.6x10-(6) molL(-1). The repeatability of current responses for injections of 5.0mmolL(-1) glucose was evaluated to be 5.3% (n=10). The resulting biosensor seemed to provide the enzymes with a biocompatible nanoenvironment as it sustained the enhanced enzyme activity for an extended time and promoted possible good electron transfer through the polymer brushes to the electrode.