Gold/cobalt ferrite nanocomposite as a potential agent for photothermal therapy

The study encompasses an investigation of optical, photothermal and biocompatibility properties of a composite consisting of golden cores surrounded by superparamagnetic CoFe2O4 nanoparticles. Accompanied with the experiment, the computational modeling reveals that each adjusted magnetic nanoparticle redshifts the plasmon resonance frequency in gold and nonlinearly increases the extinction cross-section at ~800 nm. The concentration dependent photothermal study demonstrates a temperature increase of 8.2 K and the photothermal conversion efficiency of 51% for the 100 μg/mL aqueous solution of the composite nanoparticles, when subjected to a laser power of 0.5 W at 815 nm. During an in vitro photothermal therapy, a portion of the composite nanoparticles, initially seeded at this concentration, remained associated with the cells after washing. These retained nanoparticles effectively heated the cell culture medium, resulting in a 22% reduction in cell viability after 15 min of the treatment. The composite features a potential in multimodal magneto-plasmonic therapies.