Highly sensitive AlGaN/GaN HEMT biosensors using an ethanolamine modification strategy for bioassay applications

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• AlGaN/GaN high electron mobility transistors (HEMTs) show potential for biosensing.
• Surface functionalization is crucial for improving biosensor performance.
• Existing AlGaN/GaN HEMT biosensors have limitations in sensitivity and detection limits.

Purpose of the Study:

• To develop an efficient surface modification strategy for AlGaN/GaN HEMTs.
• To enhance the performance of AlGaN/GaN HEMT-based biosensors for pH and prostate-specific antigen (PSA) detection.
• To investigate the application of ethanolamine (EA) for surface functionalization and probe immobilization.

Main Methods:

• Surface modification of AlGaN/GaN HEMT using ethanolamine (EA) to introduce amphoteric amine groups.
• Immobilization of probe molecules onto the EA-functionalized GaN surface.
• Utilizing the molecular-gated AlGaN/GaN HEMT for pH and PSA detection.
• Characterizing the biosensor's performance, including sensitivity, linearity, stability, and limit of detection (LOD).

Main Results:

• Achieved high-quality surface coating on the GaN surface with EA.
• Demonstrated excellent static electrical performance for pH sensing (high sensitivity, linearity, stability).
• Achieved a significantly low LOD of 1 fg mL⁻¹ for PSA detection, two orders of magnitude lower than previous reports.
• Observed a substantial increase in sensitivity for PSA detection, reaching 2.04% for 100 ng mL⁻¹.

Conclusions:

• The proposed EA-based surface modification strategy effectively enhances AlGaN/GaN HEMT biosensor performance.
• This method offers a promising approach for sensitive and specific biological detection using AlGaN/GaN HEMTs.
• The functionalized AlGaN/GaN HEMT biosensor shows significant potential for future applications in disease diagnosis and monitoring.