Magnetic Force Microscopy of an Oxygen‐Sensing Spin‐Probe

Abstract

Abstract In the present work we provide magnetic force microscopy (MFM) analysis on particles of a paramagnetic spin‐probe lithium octa‐ n ‐butoxy‐naphthalo‐cyanine (LiNc‐BuO) used for EPR oximetry. We demonstrate how MFM can generate a magnetic contrast in ambient air for LiNc‐BuO particles when they assemble into structures >50 nm in size. The same sample when assembled into particles <10 nm in size failed to show contrast in MFM images. The potential for utilizing MFM to understand the magnetic signature of paramagnetic nanoparticles in biological samples is discussed.