Modulating the Linker Immobilization Density on Aptameric Graphene Field Effect Transistors Using an Electric Field

Area of Science:

• Materials Science
• Biosensors
• Nanotechnology

Background:

• Aptameric graphene-based field-effect transistors (A-GFETs) utilize linkers for aptamer immobilization.
• Current linker immobilization methods result in random and uncontrollable linker density, limiting A-GFET sensitivity.
• Aptamer density directly correlates with A-GFET sensitivity.

Purpose of the Study:

• To introduce a novel electric field-based method for controlled linker immobilization on graphene.
• To establish a relationship between tunable linker density and A-GFET sensitivity.
• To enhance the detection limits of A-GFETs for specific biomarkers.

Main Methods:

• Utilized 1-pyrenebutanoic acid succinimidyl ester (PASE) as a representative linker molecule.
• Applied an electric field to align PASE molecules on graphene via electrostatic repulsion of pyrenyl groups.
• Modulated linker density by adjusting electric field parameters (voltage and duration).

Main Results:

• Achieved regular arrangement of PASE linkers on graphene using an electric field.
• Demonstrated effective modulation of linker density by tuning the electric field.
• Significantly improved the limits of detection (LODs) for interleukin-6 (IL-6) to 618 fM and insulin to 766 fM.

Conclusions:

• The electric field-driven linker immobilization method offers precise control over linker density.
• This controlled immobilization enhances the sensitivity of A-GFETs for biomarker detection.
• The developed method presents a significant advancement in optimizing A-GFET performance for sensitive diagnostics.