Radio-frequency-heating capability of silica-coated manganese ferrite nanoparticles

Mn Fe2O4nanoparticles(NPs) with various sizes and tight size-distribution were synthesized by a chemical solutionphase method.The as-synthesized NPs were coated with a silica shell of 4 nm–5 nm in thickness,enabling the watersolubility and biocompatibility of the NPs.The Mn Fe2O4 NPs with a size of less than 18 nm exhibit superparamagnetic behavior with high saturated magnetization.The capacity of the heat production was enhanced by increasing particle sizes and radio frequency(RF) field strengths.Mn Fe2O4/Si O2 NPs with 18-nm magnetic cores showed the highest heatgeneration ability under an RF field.These Mn Fe2O4/Si O2 NPs have great potentiality to cancer treatments,controlled drug releases,and remote controls of single cell functions.