Abstract
Composite nanoparticles with a gold core enveloped by cobalt ferrite
nanoparticles show potential for enhanced photothermal therapy.
Determining the optimal gold-to-cobalt ferrite nanoparticle ratio,
dependent on size, is vital for improving treatment efficiency. We
address the urgent need for advancing photothermal therapy through
utilising combined plasmon-magnetic composites with potential of
controlled directional delivery. Our computational modeling and
experimental absorption spectra analysis reveal that adjusting the
cobalt ferrite nanoparticle content redshifts the plasmon resonance
frequency in gold nanoparticles, which is accompanied by increase in the
extinction cross-section. As a result, cobalt ferrite nanoparticle
absorption dominates. Our experiments on photothermal response in
aqueous solutions of composite nanoparticles of various concentrations
demonstrate that 100 μg/ml solution yields a significant temperature
increase of ~8.2 K and a photothermal conversion
efficiency of ~51%. At this concentration, the
composite nanoparticles effectively heat the cell culture medium under
photothermal conditions, leading to 22% reduction in cell viability.