Biodegradable and Magnetic-Fluorescent Porous Silicon@Iron Oxide Nanocomposites for Fluorescence/Magnetic Resonance Bimodal Imaging of Tumor in Vivo

Considering future clinical transactions, biodegradable and luminescent porous silicon nanoparticles instead of traditional heavy-metal quantum dots have an important significance on the construction of biodegradable and magnetic-fluorescent nanocomposites. Herein, to fabricate PSiNPs@Fe 3 O 4 nanocomposites, superparamagnetic iron oxide nanoparticles were covalently incorporated into luminescent porous silicon nanoparticles by microwave-induced hydrosilylation. These resultant nanocomposites had near-infrared fluorescence (500 nm–800 nm) and superparamagnetism with high magnetic saturation value of 141 emu/g. The aqueous-dispersibility of PSiNPs@Fe 3 O 4 nanocomposites could be significantly improved via simple ultrasonication in water. Furthermore, they also exhibited an excellent biodegradability and biocompatibility, whether in vitro or in vivo . Finally, their ability of fluorescence/magnetic resonance bimodal imaging had been successfully demonstrated for cancer cells in vitro or tumor tissues in vivo .