Reliable nanometre-range distance distributions from 5-pulse double electron electron resonance

Area of Science:

• Biophysics
• Magnetic Resonance Spectroscopy
• Computational Chemistry

Background:

• Double Electron Electron Resonance (DEER) is crucial for nanometer-scale distance measurements in molecules.
• A 5-pulse DEER variant extends measurement range but introduces partial excitation and band overlap artefacts.
• Eliminating these artefacts, especially partial excitation, is challenging with standard equipment.

Purpose of the Study:

• To introduce a novel data post-processing method for removing partial excitation artefacts in 5-pulse DEER.
• To achieve artefact removal without prior knowledge of artefact amplitude or loss of sensitivity.
• To validate the method's efficacy on simulated and experimental data.

Main Methods:

• A data post-processing approach using two acquired traces with shifted artefact positions.
• Calculating the artefact shape from the difference between these two traces.
• Testing the method across diverse distance distributions and signal-to-noise ratios.

Main Results:

• Successfully removed partial excitation artefacts from 5-pulse DEER data.
• Demonstrated robustness across various distance distributions and low signal-to-noise conditions.
• Validated performance with strong artefacts common in monochromatic pulse experiments.

Conclusions:

• The developed post-processing method offers a reliable solution for artefact removal in 5-pulse DEER.
• This technique improves the accuracy and reliability of nanometer-scale distance measurements.
• It is particularly beneficial for researchers using widely available commercial spectrometers.