Magnetic spin imaging under ambient conditions with sub-cellular resolution.

Area of Science:

• Quantum sensing
• Nanoscale imaging
• Biophysics

Background:

• Detecting small numbers of magnetic spins is challenging, especially at room temperature.
• Existing methods often require external magnetic fields or are limited in sensitivity and resolution.
• Room-temperature operation is crucial for many life and chemical science applications.

Purpose of the Study:

• To demonstrate a proximal nitrogen-vacancy (NV) spin ensemble as a high-precision sensing and imaging array.
• To enable sensing of freely diffusing magnetic ions and molecules without external magnetic fields.
• To achieve direct spin noise imaging of cellular structures under ambient conditions.

Main Methods:

• Utilizing a proximal nitrogen-vacancy spin ensemble for sensing.
• Monitoring longitudinal relaxation for magnetic ion and molecule detection.
• Employing multiplexed charge-coupled device acquisition and optimized detection schemes for spin noise imaging.
• Operating within a microfluidic device under ambient conditions.

Main Results:

• Achieved spatial resolutions below 500 nm within 20 seconds.
• Reached experimental sensitivities down to 1,000 statistically polarized spins.
• Demonstrated detection of only 32 ions contributing to net magnetization.
• Successfully performed direct spin noise imaging of magnetically labelled cellular structures.

Conclusions:

• The developed NV spin ensemble serves as a versatile high-precision sensing and imaging array.
• This method allows for real-time, sub-cellular magnetic imaging and spin sensing under physiological conditions.
• It offers a minimally invasive tool for monitoring cellular processes like ion channels or haemoglobin trafficking.