Magnetically controlled single-nanoparticle detection via particle–electrode collisions

Abstract

This paper reports the magnetic control of nanoparticle collisions on gold ultramicroelectrode surface. Magnetite nanoparticles with diameters of 10 nm and modified with Prussian blue (Fe₃O₄-NPs-PB) were directed by gravitational force on the electrode surface, and spikes in current–time transients were observed. By modulating a magnetic field parallel to the electrode surface, the number of nanoparticle collisions and the nanoparticle positions could be controlled.