Rapid-scan electron paramagnetic resonance using an EPR-on-a-Chip sensor

Abstract. Electron paramagnetic resonance (EPR) spectroscopy is the method of choice to investigate and quantify species in many scientific fields, including materials science life sciences. Common EPR spectrometers use electromagnets microwave (MW) resonators, limiting their application dedicated lab environments. Here, novel aspects voltage-controlled oscillator (VCO)-based EPR-on-a-Chip (EPRoC) detectors are discussed, which have recently gained interest community. More specifically, it demonstrated that with a VCO-based EPRoC detector, amplitude-sensitive mode detection can be used perform very fast rapid-scan experiments comparatively simple experimental setup improve sensitivity compared continuous-wave regime. In place MW resonator, an array injection-locked VCOs, each incorporating miniaturized planar coil as combined source detector. A striking advantage approach possibility replacing conventionally magnetic field sweeps frequency high agility near-constant sensitivity. proof-of-concept (RS-EPRoC) performed by sweeping VCO up 400 THz s−1, corresponding sweep rate 14 kT s−1. The resulting time-domain RS-EPRoC signals micrometer-scale BDPA sample transformed into absorption precision. Considering currently available technology, range may extended 320 MHz, indicating shows great promise for future enhancements