Spherulitic copper-copper oxide nanostructure-based highly sensitive nonenzymatic glucose sensor

Area of Science:

• Nanomaterials Synthesis
• Electrochemical Sensors
• Biomedical Diagnostics

Background:

• Development of sensitive and selective glucose sensors is crucial for diabetes management.
• Nonenzymatic glucose sensors offer advantages over enzymatic sensors, such as improved stability and lower cost.
• Copper-copper oxide (Cu-CuO) nanostructures show promise for electrochemical applications due to their unique properties.

Purpose of the Study:

• To synthesize and characterize novel Cu-CuO spherulitic nanostructures.
• To fabricate and evaluate a nonenzymatic amperometric glucose sensor based on these nanostructures.
• To investigate the influence of nanostructure morphology on sensor performance.

Main Methods:

• Synthesis of Cu-CuO spherulitic nanostructures (Cu-CuOA, Cu-CuOB, Cu-CuOC) in water-in-oil microemulsions with varying surfactant concentrations.
• Characterization using UV-vis spectroscopy, X-ray diffraction, SEM, and HR-TEM.
• Fabrication of glucose sensors by depositing nanostructures on multiwalled carbon nanotube (MWCNT)-modified indium tin oxide (ITO) electrodes.
• Electrochemical performance evaluation via cyclic voltammetry and chronoamperometry.

Main Results:

• Synthesized three types of Cu-CuO spherulitic nanostructures with distinct morphologies.
• Achieved high sensitivities: 1,229 µA mM⁻¹·cm⁻² (Cu-CuOA), 3,012 µA mM⁻¹·cm⁻² (Cu-CuOB), and 3,642 µA mM⁻¹·cm⁻² (Cu-CuOC).
• Demonstrated excellent performance for Cu-CuOB: 3-second response time, 2 µM detection limit, resistance to common interfering agents, and satisfactory results in real urine and serum samples.

Conclusions:

• Cu-CuO spherulitic nanostructures are effective materials for nonenzymatic glucose sensing.
• The morphology of Cu-CuO nanostructures significantly impacts sensor sensitivity and linear range.
• The developed ITO/MWCNT/Cu-CuOB electrode shows great potential for practical glucose monitoring applications.