Diabetes is a worldwide health problem. This metabolic disorder and its related diseases are a leading cause of death in the world. These deaths can be reduced through personal control of blood glucose using a reliable and cost effective glucose biosensor.
In this research, thick-film microfabrication and electrophoretic deposition (EPD) technologies are used to produce practical glucose minibiosensors. These two technologies, in combination with Pt-Ir nano-metallic catalyst particles, were used to produce a glucose minibiosensor. The sensitivity of this minibiosensor was high and it required a lower applied potential than previous sensors.
The Pt-Ir/carbon nanoparticles showed excellent performance characteristics, such as good stability and high reactivity. The Pt-Ir/carbon nanoparticles showed good electrocatalytic activity for the oxidation of H2O2, at a relatively low applied potential.
Electrophoretic deposition (EPD) of the Pt-Ir/carbon nanoparticles, glucose oxidase, and Nafion binder was used to fabricate the glucose minibiosensors. The resulting sensors demonstrated very good stability and selectivity for glucose detection in both phosphate buffer saline (PBS) and bovine serum solution.
Electrophoretic deposition of both the nanoparticle catalyst and the enzyme was employed. The amount of deposited Pt-Ir/carbon nanoparticles and enzyme was controlled by controlling the applied potential and time of EPD.
Mixing the metallic electrocatalysts and the enzyme GOD with the carbon nanoparticles shortened the distance between the GOD and the working electrode. Therefore, the nanoparticles were in close contact with the carbon-based electrode. The H2O2 generated from the enzyme transferred directly to the electrode. Mediator-free glucose detection based on direct electron transfer was achieved.
We used the EPD modified minibiosensor to study the kinetics of glucose oxidation in both PBS solution and bovine serum. The results showed a good fit to the Michaelis-Menten kinetic model. Furthermore, this biosensor showed good long term stability and shelf life at ambient temperature.