Quaternized chitosan as support for the assembly of gold nanoparticles and glucose oxidase: application for glucose biosensing.

´MARÍA VICTORIA BRACAMONTE; SOLEDAD BOLLO; PIERRE LABBÉ; GUSTAVO RIVAS; NANCY FERREYRA

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2011 vol. 56 p. 1316 - 1316

font size="1" face="GulliverRM"> Wereport for the first time the use of quaternized chitosan (QCHI) for the immobilization of gold nanoparticles (NP) and glucose oxidase (GOD), the characterization of the resulting platform and its biocatalytic activity using glucose as substrate. The chemical substitution of chitosan has allowed us to work at physiologic pH to build up self-assembled layers of QCHI-NP as platform for the enzyme immobilization. The adsorption of GOD was analyzed by surface plasmon resonance (SPR) to compare the surface coverage of GOD in absence and presence of the QCHI-NP platform. The results obtained with cyclic voltammetry and scanning electrochemical microscopy (SECM) revealed that the adsorption of NP improves the conductivity of the structure and its electrochemical reactivity, facilitating the oxidation of the hydrogen peroxide produced by GOD. The electrodes modified with NP present higher amperometric respons