Single-layer graphene-coated gold chip for electrochemical surface plasmon resonance study

Area of Science:

• Materials Science
• Electrochemistry
• Surface Science

Background:

• Surface Plasmon Resonance (SPR) is a powerful technique for in situ surface monitoring.
• Conventional SPR chips have limitations including high background signals, narrow electrochemical windows, and poor electrochemical stability.
• Electrochemical SPR (EC-SPR) combines SPR with electrochemistry for advanced interfacial studies.

Purpose of the Study:

• To develop a novel SPR chip architecture to overcome the limitations of conventional EC-SPR setups.
• To enhance the electrochemical stability and widen the electrochemical window of SPR chips.
• To maintain the intrinsic sensitivity of SPR while improving electrochemical performance.

Main Methods:

• Fabrication of a novel SPR chip with a gold/long-chain alkane thiol self-assembled monolayer/single-layer graphene (Au/SAM/G) sandwich architecture.
• Utilizing the single-layer graphene as the working electrode and the gold film as the SPR substrate.
• Employing the thiol monolayer for electrical separation between graphene and gold to prevent gold polarization.

Main Results:

• The novel Au/SAM/G chip demonstrated a significantly extended electrochemical window beyond hydrogen/oxygen evolution potentials.
• Improved electrochemical stability and suppressed background signals were observed compared to conventional SPR chips.
• The intrinsic SPR sensitivity of the Au/SAM/G chip was fully retained.

Conclusions:

• The developed Au/SAM/G sandwich architecture provides a robust solution for EC-SPR investigations.
• This novel chip design addresses key limitations, enabling EC-SPR studies under harsher electrochemical conditions.
• The enhanced EC-SPR chip offers a valuable tool for advanced interfacial analysis.