Glucose oxidase-Tm2O3 nanoparticle-modified electrode for direct electrochemistry and glucose sensing

Due to their physicochemical properties, Tm2O3 nanoparticles have been employed in bioanalytical applications. In this report, body-centered shaped Tm2O3 nanoparticles with size of about 10 nm were successfully synthesized by the hydrothermal homogeneous method and used as a novel electrochemical biosensing platform for glucose based on a Tm2O3-Nafion modified electrode. Transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS) were used to characterize the Tm2O3 nanoparticles, and cyclic voltammetry (CV) was used to investigate the electrochemical behavior of the modified electrode. The experimental results showed that glucose oxidase (GOD) immobilized on the Nafion-Tm2O3 film achieved direct electron transfer with an apparent heterogeneous electron transfer rate constant (ks) of 3.27 +/- 0.43 s(-1) and kept its bioactivity. Confirmation of the retained bioactivity can be demonstrated by its bioelectrocatalytic activity to the reduction of dissolved oxygen. The GOD/Tm2O3/Nafion/GC electrode displayed potential application for the fabrication of glucose biosensors with a linear glucose response up to 7 mM. Additionally, the biosensor based on the Tm2O3 nanoparticle-modified electrode exhibited good stability and selectivity. The successful practice of using the Tm2O3 modified electrode for the direct electrochemical analysis of proteins and the bioelectrocatalytic activity of enzymes offers an efficient strategy and a new promising platform for the application of rare earth oxide materials in the field of electrochemical sensors. (C) 2010 Elsevier B.V. All rights reserved.