Polyethylene Glycol Functionalized Silicon Nanowire Field-Effect Transistor Biosensor for Glucose Detection

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Biosensors

Background:

• Accurate blood glucose monitoring is vital for diabetes diagnosis and management.
• Existing biosensors face challenges in high ionic strength solutions due to the Debye screening effect.

Purpose of the Study:

• To develop a silicon nanowire field-effect transistor (SiNW-FET) biosensor for direct glucose detection.
• To overcome the Debye screening effect for improved biosensor performance in complex biological fluids.

Main Methods:

• Modification of SiNW surface with a "mixed-catalyzer layer" and a porous biopolymer layer (polyethylene glycol - PEG).
• Optimization of the surface modification ratio (APTMS:silane-PEG = 2:1).
• Utilized glucose oxidase enzyme for glucose detection.

Main Results:

• The modified SiNW-FET biosensor demonstrated direct glucose detection in high ionic strength solutions.
• Achieved high sensitivity (0.47 μAcm^-2mM^-1) and a low detection limit (10 nM).
• Exhibited a fast response time of less than 8 seconds.

Conclusions:

• The developed biosensor effectively overcomes Debye screening, enabling sensitive and specific glucose detection.
• The SiNW-FET biosensor shows significant potential for clinical applications in disease diagnosis.
• The sensor offers advantages of high sensitivity, specificity, and real-time response for glucose monitoring.