Synthesis, inductive heating, and magnetoimpedance-based detection of multifunctional Fe3O4 nanoconjugates

We report on the synthesis, inductive heating, and detection of a multifunctional nanosystem, which is composed of magnetite (Fe3O4) nanoparticles and two natural compounds, Alginate (Alg) and Curcumin (Cur). Alg was first absorbed onto the surface of Fe3O4 nanoparticles followed by loading of Cur in the nanoconjugate. The presence of Alg and Cur were confirmed by Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, and transmission electron microscopy. The inductive heating capacity of the functionalized Fe3O4 nanoparticles was investigated under different alternating magnetic fields at 236 kHz, indicating that these nanoparticles are a promising agent for heat production in hyperthermia applications. Sensitive detection of the functionalized nanoparticles at various concentrations was carried out using a novel magnetoimpedance-based biosensor. High detection sensitivity was achieved at low particle concentration with saturated detection at an upper limit, as particle concentration exceeds a critical value. Our study indicates that the magnetic nanoconjugate of Fe3O4 nanoparticles encapsulated by Alg and Cur is a promising nanosystem for applications in drug delivery, hyperthermia, and biodetection.