Highly sensitive glucose biosensor based on Au-Ni coaxial nanorod array having high aspect ratio

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Biosensor Technology

Background:

• Effective glucose biosensors rely on maximizing glucose oxidase (GOx) immobilization.
• Three-dimensional (3D) nanorod array electrodes offer a higher surface-to-volume ratio compared to 2D structures, enabling greater GOx loading.

Purpose of the Study:

• To develop a highly sensitive glucose biosensor using a novel 3D Au-Ni coaxial nanorod array electrode.
• To evaluate the performance of this electrode for glucose detection, including sensitivity, linear range, detection limit, selectivity, and stability.

Main Methods:

• Fabrication of Au-Ni coaxial nanorod arrays using nano electroforming and immersion gold (IG) techniques.
• Characterization of nanorod dimensions (diameter, height, aspect ratio) and surface area enhancement.
• Electrochemical performance evaluation for glucose detection through sensitivity, linear range, and limit of detection measurements.
• Assessment of selectivity against interfering substances (uric acid, ascorbic acid) and long-term stability over 30 days.

Main Results:

• The Au-Ni coaxial nanorod array electrode exhibited a 79.8-fold increase in effective sensing area compared to a flat Au electrode.
• The biosensor demonstrated a linear detection range from 27.5 μM to 27.5 mM for glucose.
• A low detection limit of 5.5 μM and high sensitivity of 769.6 μA mM⁻¹cm⁻² were achieved.
• The sensor showed good selectivity and maintained stability over 30 days.

Conclusions:

• The developed Au-Ni coaxial nanorod array electrode is a promising platform for highly sensitive and stable glucose biosensing.
• The 3D nanostructure design effectively enhances GOx immobilization and electrochemical performance.
• This approach offers a significant advancement for glucose monitoring applications.