Multiplexed Crossbar GFET Array With BioADC for Multi-Modal Aptamer-Based Sensing

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Graphene field-effect transistors (GFETs) offer high surface-to-volume ratios for sensing applications.
• Integrating GFETs with low-power electronics is crucial for portable biosensing.

Purpose of the Study:

• To develop a scalable, low-power GFET crossbar array integrated with a neural-interface system-on-chip (NISoC).
• To enable multiplexed, real-time biomolecular sensing, including ultra-sensitive detection of lead ions (Pb2+).

Main Methods:

• Fabrication of a 12x12 GFET crossbar array using optimized graphene transfer and a multilayer dielectric stack.
• Characterization using benchtop instrumentation and a low-power NISoC front-end.
• Functionalization with G-quadruplex ssDNA aptamers for Pb2+ detection.

Main Results:

• Demonstrated uniform GFET behavior, reversible pH-dependent conductance, and predictable ionic strength responses.
• Achieved femtomolar-level detection of Pb2+ with high selectivity over Ca2+ and Co2+.
• The GFET-NISoC platform operated at sub-μW power levels.

Conclusions:

• The GFET-NISoC platform enables multiplexed, multi-modal sensing with ultra-low power consumption.
• This technology provides a promising foundation for wearable or point-of-care chemical and biomolecular monitoring.
• The system demonstrates potential for sensitive and selective detection of heavy metal ions.