Core–Shell Fe<sub>3</sub>O<sub>4</sub>@Au Nanorod-Loaded Gels for Tunable and Anisotropic Magneto- and Photothermia
Mikel Rincón‐Iglesias, Irati Rodrigo, Leixuri B. Berganza, Esraa Samy Abu Serea, F. Plazaola, S. Lanceros‐Méndez, Erlantz Lizundia, Javier Reguera
Abstract
Hyperthermia therapeutic treatments require improved multifunctional materials with tunable synergetic properties. Here, we report on the synthesis of Fe3O4@Au core–shell nanorods and their subsequent incorporation into an agarose hydrogel to obtain anisotropic magnetic and optical properties for magneto- and photothermal anisotropic transductions. Highly monodisperse ferrimagnetic Fe3O4 nanorods with tunable size were synthesized using a solvothermal method by varying the amount of hexadecylamine capping ligands. A gold shell was coated onto Fe3O4 nanorods by the intermediate formation of core-satellite structures and a subsequent controlled growth process, leading to an optical response variation from the visible to the near-infrared (NIR) region. The nanorods were oriented within an agarose hydrogel to fabricate free-standing anisotropic materials, providing a proof-of-concept for the applicability of these materials for anisotropic magneto- and photothermia applications. The strong gelling behavior upon cooling and shear-thinning behavior of agarose enable the fabrication of magnetically active continuous hydrogel filaments upon injection. These developed multifunctional nanohybrid materials represent a base for advanced sensing, biomedical, or actuator applications with an anisotropic response.