Single-DNA electron spin resonance spectroscopy in aqueous solutions

Area of Science:

• Biophysics
• Quantum Sensing
• Molecular Biology

Background:

• Studying single biomolecules is crucial for understanding biological function.
• Magnetic resonance spectroscopy (MRS) offers detailed molecular insights but is challenging at the single-molecule level, especially under physiological conditions.

Purpose of the Study:

• To develop a method for performing magnetic resonance spectroscopy on individual biomolecules under near-physiological conditions.
• To demonstrate the feasibility of studying single DNA duplexes using advanced sensing techniques.

Main Methods:

• Utilized nitrogen-vacancy (NV) centers in diamond as highly sensitive spin sensors.
• Detected electron spin resonance (ESR) spectra of individual DNA duplexes tethered and labeled with a nitroxide spin label.
• Performed measurements in aqueous buffer solutions at ambient temperatures to mimic native-like environments.

Main Results:

• Successfully obtained ESR spectra from single, tethered DNA duplexes.
• Demonstrated the capability of NV centers to detect spin signals from individual biomolecules in solution.
• Achieved measurements under near-physiological conditions (aqueous buffer, ambient temperature).

Conclusions:

• This work establishes a novel approach for single-molecule magnetic resonance studies.
• The developed technique paves the way for investigating biomolecular function and interactions in native-like environments.
• Advances the field of biophysics by enabling unprecedented studies on individual molecules.