A Highly Responsive Silicon Nanowire/Amplifier MOSFET Hybrid Biosensor

Area of Science:

• Nanotechnology
• Electrical Engineering
• Biomedical Engineering

Background:

• Field-effect-transistor (FET)-based biosensors offer label-free detection but often suffer from limited current response.
• Silicon nanowires (SiNWs) are promising for biosensing due to their high surface-to-volume ratio.
• Improving the sensitivity and signal amplification of SiNW biosensors is crucial for practical applications.

Purpose of the Study:

• To develop a hybrid biosensor integrating SiNWs with an amplifier MOSFET.
• To enhance the current response and overall performance of FET-based biosensors.
• To demonstrate the biosensor's capability for sensitive detection of biomolecules and charged polymers.

Main Methods:

• Fabrication of a hybrid biosensor using complementary metal-oxide-semiconductor (CMOS) technology.
• Integration of silicon nanowires (SiNWs) with a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) amplifier.
• Characterization of the biosensor's performance for pH detection and charged polymer detection.

Main Results:

• The hybrid biosensor achieved a remarkable current response of 5.74 decades per pH for pH detection.
• This represents a 2.5 × 10^5 times improvement compared to single SiNW sensors.
• Demonstrated high current change (4.5 × 10^5) for detecting 500 nM poly(allylamine hydrochloride).
• Achieved a wide dynamic range by adjusting the liquid gate voltage.

Conclusions:

• The hybrid SiNW-MOSFET biosensor significantly enhances current response for FET-based sensors.
• CMOS fabrication enables high-density, low-noise biosensor development.
• The demonstrated sensitivity and dynamic range make this biosensor practical for demanding applications.