An effective hydroxylation route for a highly sensitive glucose sensor using APTES/GOx functionalized AlGaN/GaN high...

Area of Science:

• Materials Science
• Biotechnology
• Electrical Engineering

Background:

• High electron mobility transistors (HEMTs) offer potential for sensitive biosensing applications.
• Surface modification of semiconductor materials is crucial for effective biomolecule immobilization.
• Gallium nitride (GaN) surfaces require functionalization for biosensor development.

Purpose of the Study:

• To fabricate a highly sensitive glucose sensor using an AlGaN/GaN HEMT platform.
• To investigate the hydroxylation of GaN surfaces for improved biosensor performance.
• To immobilize glucose oxidase (GOx) onto the functionalized GaN surface for glucose detection.

Main Methods:

• Fabrication of an AlGaN/GaN HEMT.
• Surface hydroxylation of GaN using UV-irradiated hydrogen peroxide (H2O2) to generate hydroxyl radicals.
• Immobilization of glucose oxidase (GOx) via self-assembled monolayers (SAMs) of 3-aminopropyltriethoxysilane (APTES).
• Characterization of surface chemical groups using X-ray photoelectron spectroscopy (XPS).
• Analysis of current signals for glucose detection.

Main Results:

• Successful hydroxylation of the GaN surface was confirmed by XPS.
• The APTES/GOx modified AlGaN/GaN HEMT biosensor showed a linear response to glucose from 10 to 100 µM.
• Achieved a high sensitivity of 3.15 × 10^4 µA mM^-1 cm^-2.
• Demonstrated a low detection limit of 10 nM for glucose.
• The biosensor exhibited good current response to glucose.

Conclusions:

• The hydroxylation of GaN surfaces is an effective strategy for developing AlGaN/GaN HEMT-based biosensors.
• The developed glucose sensor demonstrates high sensitivity and a low detection limit.
• This approach holds promise for future advancements in HEMT-based biosensor design and applications.