Fe3O4@Au@SiO2 Core–Shell Nanoparticles: Synthesis,  Characterization, Investigations of Its Influence on Cell Lines Using  a NIR Laser and an Alternating Magnetic Field

Core–shell nanoparticles (CSNPs) have attracted attention in biomedical applications as they have highly useful materials with modified characteristics, such as high stability, dispersibility, higher permeability to certain target cells and reduction in consumption of precious materials. Synthesis of core–multishell nanoparticles with suitable sizes, structural characteristics and absorption using simple methods continues to be a challenge. In this study, \({\text{F}\text{e}}_{3}{\text{O}}_{4}@\text{A}\text{u} @{\text{S}\text{i}\text{O}}_{2}\)  CSNPs were synthesized in three stages to control their size and the potential for tuning their properties. Field emission scanning electron microscope images confirmed that \({\text{F}\text{e}}_{3}{\text{O}}_{4}@\text{A}\text{u} @{\text{S}\text{i}\text{O}}_{2}\) CSNPs have a small particle size of about 22.5 nm, average crystalline size in X-ray diffractometer analysis was 22.8 nm, stability was about − 49.1 mV, and synthesis with magnetic and optical properties improved their biocompatibility. Treatment of CAL-51 and HBL-100 cell lines by \({\text{F}\text{e}}_{3}{\text{O}}_{4}@\text{A}\text{u} @{\text{S}\text{i}\text{O}}_{2}\)  CSNPs under NIR laser and alternating magnetic field generated enough heat to increase cell death.