Glucose oxidase–Tm 2O 3 nanoparticle-modified electrode for direct electrochemistry and glucose sensing

Abstract

Due to their physicochemical properties, Tm 2O 3 nanoparticles have been employed in bioanalytical applications. In this report, body-centered shaped Tm 2O 3 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 Tm 2O 3–Nafion modified electrode. Transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS) were used to characterize the Tm 2O 3 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–Tm 2O 3 film achieved direct electron transfer with an apparent heterogeneous electron transfer rate constant ( k s ) 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/Tm 2O 3/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 Tm 2O 3 nanoparticle-modified electrode exhibited good stability and selectivity. The successful practice of using the Tm 2O 3 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.