A highly sensitive label-free electrochemical immunosensor based on an aligned GaN nanowires array/polydopamine...

Area of Science:

• Nanomaterials Science
• Electrochemical Sensors
• Biotechnology

Background:

• Aligned Gallium Nitride (GaN) nanowire arrays offer potential for biosensors due to stability and high electron mobility.
• Surface modification of GaN nanowires is crucial for efficient charge transfer and antibody immobilization in electrochemical immunosensors.
• Developing effective surface modification strategies for GaN nanowires remains a challenge.

Purpose of the Study:

• To develop a highly sensitive, label-free electrochemical immunosensing platform using modified GaN nanowire arrays.
• To investigate the role of polydopamine (PDA) integration in enhancing charge transfer and antibody immobilization.
• To demonstrate the efficacy of the fabricated immunosensor for detecting biomarkers such as alpha-fetoprotein (AFP).

Main Methods:

• Self-assembly of polydopamine (PDA) polymer onto aligned GaN nanowire surfaces via organic polymerization.
• Modification of GaN nanowire array/PDA hybrids with gold nanoparticles for antibody covalent binding.
• Fabrication of an electrochemical immunosensor for label-free detection of AFP.

Main Results:

• The GaN nanowire array/PDA heterointerface facilitated efficient charge transfer.
• The immunosensor exhibited a wide linear range (0.01–100 ng mL⁻¹) and a low detection limit (0.003 ng mL⁻¹) for AFP.
• The sensor demonstrated good selectivity, reproducibility, stability, and successful application in human serum samples.

Conclusions:

• The integration of PDA on GaN nanowire arrays provides an effective strategy for electrochemical immunosensor development.
• The semiconductor/polymer heterointerface significantly enhances the sensitivity of the immunosensing platform.
• This approach offers a promising method for sensitive and reliable biomarker detection in clinical diagnostics.