Hybrid Magneto-Plasmonic Nanostructures for Enhanced Dual-Mode Hyperthermia

This study addresses a major challenge in hyperthermia therapy: achieving fast and efficient heat generation in target tissues. A novel magneto-plasmonic nanostructure is developed by combining gold nanorods (GNRs) and iron oxide nanoparticles (IONPs), each synthesized independently to compare their individual and combined heating performance. A key innovation was the use of (3-mercaptopropyl)trimethoxysilane (MPTMS) as a covalent linker, enabling the stable integration of both components into a single hybrid system. Under simultaneous near-infrared (NIR) laser and alternating magnetic field exposure, the hybrid nanostructure exhibited a rapid and intense temperature rise, surpassing the effects of either material alone. A control sample consisting of a physical mixture of the two components (GNR + IONP) reached SAR values comparable to those of the covalently linked hybrid (GNR + MPTMS + IONP) under simultaneous excitation, the two being equal within experimental error. Although the chemical linkage modifies the optical absorbance of the GNRs and may partially restrict the Brownian relaxation of the magnetic nanoparticles, these effects do not translate into a measurable loss of heating efficiency under combined activation. Importantly, the covalent linkage yields a robust, structurally stable assembly whose components move together-an essential requirement for functionalities such as magnetic guidance and targeted delivery of the whole nanostructure, which a simple physical mixture cannot provide. As a physicochemical proof of concept, these results establish the dual-mode heating performance of the hybrid nanostructure in aqueous suspension and motivate the biological evaluation required for any future therapeutic use.