Enhancing Nonenzymatic Glucose Detection Through Cobalt-Substituted Hafnia

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing selective glucose sensors is crucial for diabetes management.
• Ultrathin metal oxide films offer potential for advanced sensing applications.

Purpose of the Study:

• To investigate engineered defect chemistry in ultrathin cobalt-doped hafnia (HCO) for selective glucose sensing.
• To explore the use of chemical solution deposition (CSD) for fabricating ultrathin HCO films.

Main Methods:

• Fabrication of ultrathin HCO films (≈5 nm) using CSD on silicon substrates.
• Analysis of phase transformation (monoclinic to orthorhombic) in HCO films.
• Electrocatalytic evaluation for glucose oxidation in the presence of interfering species.
• Theoretical investigation of oxygen vacancies and their role in enhancing electrocatalytic activity.

Main Results:

• HCO thin films exhibited significant glucose sensing activity.
• A monoclinic to orthorhombic phase transformation was observed.
• The presence of multivalent cobalt and oxygen vacancies enabled selective glucose oxidation with minimal interference.
• Theoretical studies confirmed enhanced electrocatalytic activity due to oxygen vacancies promoting charge transfer.

Conclusions:

• Ultrathin CSD-processed HCO films demonstrate high selectivity, repeatability, and reproducibility for glucose sensing.
• Engineered defect chemistry in HCO is a promising strategy for developing advanced biosensors.
• CSD is viable for producing ultrathin films for selective sensing applications.