A Graphene Field-Effect Transistor-Based Biosensor Platform for the Electrochemical Profiling of Amino Acids

Area of Science:

• Materials Science
• Biotechnology
• Analytical Chemistry

Background:

• Electrochemical fingerprinting offers a promising strategy for identifying amino acids and peptides.
• Recent advancements in protein manipulation are crucial for developing effective sequencing technologies.

Purpose of the Study:

• To establish a graphene field-effect transistor (GFET)-based platform for probing amino acid electrochemical fingerprints.
• To enable stable surface chemistry and controlled electrochemical measurements for peptide and protein sequencing.

Main Methods:

• Developed a graphene functionalization protocol for directional amino acid attachment.
• Quantitatively characterized surface chemistry using surface plasmon resonance (SPR), achieving densities of 10^12 molecules/cm^2.
• Demonstrated in situ peptide synthesis directly on graphene and developed complementary platforms for sensor preconditioning, functionalization, and electrochemical measurements.

Main Results:

• Achieved high surface densities of functionalized amino acids on graphene.
• Successfully synthesized a model tripeptide on the graphene surface.
• Demonstrated sensor stability with Dirac point drift below 10 mV over 45 minutes.

Conclusions:

• Established the experimental foundation for electrochemical amino acid and peptide fingerprinting using GFET sensors.
• Provided a framework for advancing electrochemically enabled protein sequencing technologies.