Fast Broad-Band Magnetic Resonance Spectroscopy with Diamond Widefield Relaxometry

Fast Broad-Band Magnetic Resonance Spectroscopy with Diamond Widefield Relaxometry

ACS Sensors (2023)

This study introduces a novel approach to Electron Paramagnetic Resonance (EPR) spectroscopy using the photoluminescence of Nitrogen-Vacancy centers in diamonds, bypassing traditional bulky EPR equipment. By monitoring the relaxation time (T1) and utilizing a localized magnetic field gradient, the technique successfully detects cross-relaxation with compounds of interest. Remarkably, it reconstructs a full EPR spectrum in just 3 seconds across a 3 to 11 G range, with a minimal volume requirement of 0.5 μL for a 1 μM hexaaquacopper(II) ion solution. This method represents a significant advance in sensitivity and efficiency for EPR spectroscopy.