Controllable Cobalt Oxide/Au Hierarchically Nanostructured Electrode for Nonenzymatic Glucose Sensing

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Biosensing

Background:

• Development of efficient electrochemical sensors for glucose detection is crucial for managing diabetes.
• Existing glucose sensors often face challenges with sensitivity, selectivity, and stability.
• Nanostructured materials offer unique properties for enhanced electrochemical sensing applications.

Purpose of the Study:

• To develop a facile, cost-effective, and environmentally friendly synthesis route for a cobalt oxide/Au hierarchically nanostructured electrode.
• To investigate the electrochemical sensing performance of the developed electrode for glucose oxidation.
• To evaluate the suitability of the sensor for detecting glucose in complex biological matrices like human serum.

Main Methods:

• Two-step synthesis involving electrodeposition and galvanic replacement reaction to create cobalt oxide/Au nanostructures.
• Characterization using transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, energy-dispersive spectrometry (EDS), and X-ray photoelectron spectroscopy (XPS).
• Electrochemical performance evaluation using cyclic voltammetry (CV) and amperometric (i-t) response.

Main Results:

• The cobalt oxide/Au electrode exhibited excellent electrocatalytic activity for glucose oxidation.
• A wide linear detection range from 0.2 μM to 20 mM was achieved.
• A low detection limit of 0.1 μM (S/N=3) was obtained, demonstrating high sensitivity.
• The sensor showed good selectivity and stability, attributed to the synergistic effect of cobalt oxide and gold nanoparticles.

Conclusions:

• The facile synthesis method yields a controllable cobalt oxide/Au hierarchically nanostructured electrode.
• The developed electrode demonstrates superior performance for glucose sensing, including high sensitivity and a wide linear range.
• The sensor is suitable for practical applications, such as detecting glucose in human serum samples.