Real-time detection of single magnetic nanoparticle with interferometric scattering microscopy

Abstract

Magnetic nanoparticles (MNPs) have extensive applications in multimodal imaging, drug delivery and cell therapy techniques due to the magnetic and chemical properties. However, existing methods only can detect the signal of hundreds of MNPs, hindering insights into their dynamic behaviors in microscopic scale. In this study, we propose an interferometric scattering (iSCAT) microscopy based method to track the motion of single MNP in the pure water. In our method, we induce directional displacement of MNPs with applying a magnetic field gradient. Experimental results show that the motion of MNPs is consistently aligned with the magnetic field direction, validating the feasibility of the proposed method. The proposed method provides a promising approach to reveal the microscopic behaviour of MNPs.