Diamond rotors.

Area of Science:

• Materials Science
• Analytical Chemistry
• Spectroscopy

Background:

• Magic Angle Spinning (MAS) Nuclear Magnetic Resonance (NMR) spectral resolution is limited by rotor spinning frequency.
• Current MAS rotor materials, like zirconia, have mechanical limitations restricting achievable spinning speeds.
• High spinning frequencies are crucial for resolving complex biological structures using MAS NMR.

Purpose of the Study:

• To overcome the limitations of current MAS rotor materials by fabricating rotors from single crystal diamond.
• To achieve unprecedented MAS frequencies for enhanced NMR spectral resolution.
• To explore the potential of diamond rotors for improving sensitivity in Dynamic Nuclear Polarization (DNP) experiments.

Main Methods:

• Fabrication of single crystal diamond MAS rotors using novel laser micromachining techniques.
• Optimization of rotor-bearing systems for high-speed spinning using helium gas.
• Recording proton-detected 13C/15N MAS NMR spectra using the novel diamond rotors.

Main Results:

• Diamond rotors achieved stable spinning frequencies of 111.000 ± 0.004 kHz, with stable operation up to 124 kHz.
• Demonstrated the first proton-detected 13C/15N MAS NMR spectra obtained with diamond rotors.
• Overcame previous fabrication challenges related to the high aspect ratio of MAS rotors.

Conclusions:

• Single crystal diamond rotors represent a significant advancement in MAS NMR technology.
• The achieved high spinning frequencies open new possibilities for studying previously inaccessible ex-vivo protein samples.
• Diamond's properties offer potential for further improvements in NMR sensitivity, particularly in DNP-enhanced experiments.