YIG-based Sensor System for Millisecond Time Range Magnetorelaxometry.

In the current study we propose a magneto-optical system for registration and analysis of magnetic nano- and microparticles magnetic relaxation. The core of our system is the novel compact magnetometer based on an yttrium-iron garnet film and working at room temperature. The sensor demonstrates sensitivity of 35 pT/√{Hz} at 79 Hz and recovery time less than 100 μ s, which allows to register quite fast magnetic relaxations of a low amplitude. All these facts make the system feasible for usage in biological magnetorelaxometry and theranostics. Statistical processing of the relaxation curves allowed us to estimate both amplitudes and relaxation times for various biocompatible magnetic particles at the amount of 100 μ g in the test tubes experiments. The system has a great potential of further development for usage in the areas of targeted drug delivery, hyperthermia, magnetic imaging. Being comparatively cheap, the system potentially is of a great interest in the fields of biomedicine and nanomedicine.