Mesostructured multifunctional magnetic nanocomposites for potential applications

Abstract

Multifunctional nanocomposites with mesoporous silica having superparamagnetic, near-infrared (NIR) plasmon resonance, and catalytic behavior, were synthesized. These nanocomposites, with an inner magnetite core, an outer mesoporous silica shell, and a gold shell sandwiched between a thin silica layer and a thick outer silica shell, were characterized using different techniques, such as transmission electron microscopy, X-ray diffraction, fourier transform infrared spectroscopy, vibrating sample magnetometer, UV-vis spectroscopy, X-ray photoelectron spectrometry, dynamic light scattering, zeta potential, N-2 adsorption/desorption, and thermal gravimetric analysis. The results indicated that the nanocomposites have high magnetization (21.4 emu/g) due to the inner magnetite core, significant absorbance in the NIR region due to the gold shell, large surface area (315 m(2)/g), and mesopores (2.1 nm) in the outer silica shell. The outer mesoporous silica shell was investigated for adsorption and release of drug as well as for attaching of dye molecules, while the gold shell was investigated its catalytic behavior. These multifunctional nanocomposites show adsorption and sustained release of ibuprofen, and also have excellent catalytic behavior. (C) 2013 Elsevier B.V. All rights reserved.