Diamond surface functionalization via visible light-driven C-H activation for nanoscale quantum sensing.

Area of Science:

• Quantum sensing
• Materials science
• Nanotechnology

Background:

• Nitrogen-vacancy (NV) centers in diamond are key for nanoscale NMR sensing.
• Current methods for functionalizing diamond surfaces are harsh and limit molecular diversity.
• Attaching molecules to diamond for single-molecule spectroscopy remains a challenge.

Purpose of the Study:

• To develop a versatile and gentle method for functionalizing single-crystal diamond surfaces.
• To enable NV-center-based sensing and spectroscopy of individual molecules.
• To overcome limitations of existing diamond surface modification techniques.

Main Methods:

• Direct functionalization of C-H bonds on single-crystal diamond using visible light.
• Formation of C-F, C-Cl, C-S, and C-N bonds under ambient conditions.
• Utilizing shallow NV centers with long spin coherence times.

Main Results:

• A versatile strategy for direct diamond surface functionalization was established.
• The method is compatible with shallow NV centers, preserving long spin coherence.
• Demonstrated NV-center detection of nuclear spins from surface-bound functional groups.

Conclusions:

• The developed method allows for diverse surface functionalization of diamond under mild conditions.
• This approach facilitates the use of NV centers for advanced chemical sensing.
• Opens new avenues for single-molecule spectroscopy using diamond-based quantum sensors.