Enhancing the Sensitivity and Detection Depth of a Single-Sided Magnetic Particle Spectrometer Using Ferrite Cores

Abstract

Magnetic particle spectroscopy (MPS), first developed in relation to magnetic particle imaging (MPI) since its introduction in 2005, has been widely applied in biomedical detection and the evaluation of magnetic nanoparticle (MNP) performance in MPI. Its high sensitivity, low cost, and portability make MPS an essential tool for these applications. However, traditional MPS devices are limited by their enclosed measurement chambers, which restrict their application to solutions placed in small test tubes. Therefore, developing MPS devices that are not constrained by the size of the subject is crucial for clinical applications. Single-sided MPS devices, which concentrate the coils on one side, are not restricted by the size of the object being measured, making them directly applicable to clinical research. However, single-sided MPS devices are currently limited in terms of detection depth and sensitivity due to the rapid attenuation of the magnetic field with distance. To address this issue, in this work, we propose incorporating a soft magnetic core (Mn-Zn ferrite) into the single-sided MPS to enhance the magnetic flux density of the excitation field, thereby increasing detection depth. Additionally, we introduce a surface receiving coil design to replace the traditional solenoidal receiving coil, further improving sensitivity. The results demonstrate that the sensitivity increases by approximately ten times, and the detection depth is doubled.