Open-Bandgap Graphene-Based Field-Effect Transistor Using Oligo(phenylene-ethynylene) Interfacial Chemistry.

Area of Science:

• Materials Science
• Nanotechnology
• Biochemistry

Background:

• Stable immobilization of bioprobes is crucial for nanobiosensor development.
• Graphene and other 2D nanomaterials offer promising platforms for biosensing applications.
• Organic interfacial compounds (OICs) act as essential linkers for bioprobe immobilization.

Purpose of the Study:

• To develop a stable and efficient method for bioprobe immobilization on graphene using OICs.
• To investigate the potential of oligo(phenylene-ethynylene)amine (OPE) as an OIC for nanobiosensor fabrication.
• To demonstrate the performance of a graphene-based field-effect transistor (FET) biosensor utilizing OPE.

Main Methods:

• Fabrication of a graphene field-effect transistor (FET) using microelectromechanical systems (MEMS) processing.
• Covalent functionalization of large-scale graphene with oligo(phenylene-ethynylene)amine (OPE).
• Comparison of OPE with other OICs using density functional theory (DFT) simulations.
• Immobilization of Magainin I bioprobe onto the functionalized graphene surface.
• Characterization of the resulting biosensor (OGMFET) performance.

Main Results:

• DFT simulations confirmed OPE has higher binding energy with graphene and a lower band gap compared to other OICs.
• OPE facilitated the formation of a self-assembled monolayer, improving bioprobe immobilization efficiency.
• The Magainin I-conjugated OGMFET (MOGMFET) exhibited high sensitivity and selectivity.
• A limit of detection of 10^0 CFU/mL was achieved for pathogen detection.

Conclusions:

• OPE is a superior OIC for stable and efficient bioprobe immobilization on graphene.
• The OPE-based interfacing technology enables the development of highly sensitive and selective nanobiosensors.
• This approach holds significant potential for advanced biosensor fabrication and applications.