Surface potential modulates fibronectin adsorption and molecular interaction on graphene-based materials.

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Nanotechnology

Background:

• Protein interactions with graphene-based materials (GBMs) are influenced by surface properties.
• The role of surface potential (SP) in modulating these interactions is not well understood.

Purpose of the Study:

• To investigate how distinct surface potentials of graphene oxide (GO) and reduced graphene oxide (RGO) affect protein adsorption and conformation.
• To elucidate the influence of SP on protein-material interactions at both macroscopic and molecular levels.

Main Methods:

• Thermal reduction of GO to RGO to create materials with different SPs (+120 mV for GO, +60 mV for RGO).
• Quartz crystal microbalance with dissipation and fluorescence microscopy to study fibronectin (FN) adsorption.
• Molecular docking simulations to analyze protein-material binding interactions.

Main Results:

• Reduced graphene oxide (RGO) showed approximately 3 times greater fibronectin (FN) adsorption than graphene oxide (GO).
• FN adsorbed onto GO exhibited elongated fibrillar structures due to strong polar and electrostatic interactions.
• Molecular docking revealed stronger binding affinity between FN and RGO compared to FN and GO.

Conclusions:

• Surface potential is a critical factor in governing protein adsorption, stability, and conformational changes on GBMs.
• Tailoring the SP of GBMs can rationally design biomaterials with specific biointerface properties for controlled protein interactions.