A Compact Sensory Platform Based pH Sensor Using Graphene Field Effect Transistor.

Area of Science:

• Materials Science
• Nanotechnology
• Biosensors

Background:

• Graphene field-effect transistors (GFETs) offer unique electronic properties for sensing applications.
• Developing compact and sensitive platforms for biomolecule identification is crucial in diagnostics.

Purpose of the Study:

• To fabricate and characterize a compact GFET-based sensory platform for pH sensing.
• To evaluate the performance of the GFET device in detecting pH variations in buffer solutions.

Main Methods:

• Fabrication of a monolayer GFET device with an integrated top-gate.
• Measurement of electrical characteristics, specifically the Dirac point (V_Dirac) and transfer curves, after buffer solution desiccation.
• Analysis of V_Dirac shifts and transfer curve movements in response to varying pH levels.

Main Results:

• The GFET device successfully detected pH changes, with the V_Dirac point shifting positively as pH increased.
• A sensitivity of approximately 48.5 mV/pH was achieved, indicating a robust response to pH variations.
• Observed charge transfer from dopant molecules to the graphene surface correlated with increasing pH.

Conclusions:

• A compact GFET device with an in-built gate enables effective pH sensing.
• This platform provides a user-friendly interface for advanced biosensing applications.
• The GFET sensor demonstrates potential for sensitive and reliable biomolecule identification via pH monitoring.