The role of Zn2+ on structure, magnetic properties, and drug delivery performance of ZnxFe3–xO4/SiO2 nanocomposites
摘要
A series of ZnxFe3–xO4/SiO2 nanocomposites (x = 0, 0.1, and 0.9) for drug delivery applications has been successfully prepared using coprecipitation and sol–gel methods. X-ray diffraction analysis showed a shift in the ZnxFe3–xO4 peaks to lower 2θ due to the role of incorporating Zn2+, associated with increasing lattice parameters from 8.377 Å to 8.388 Å in the spinel structure. In addition, a broad peak appeared at 2θ ≈ 22o–24o, originating from amorphous SiO2. The metal–oxygen bonds (Zn–O and Fe–O) were detected at octahedral (526–535 cm–1) and octahedral (409–480 cm–1) sites. The symmetric and asymmetric vibrations of Si–O–Si were detected at 805–941 cm–1 and 1067–1094 cm–1, respectively. The stretching vibrations of Fe–O–Si were detected at 544–580 cm–1, indicating a chemical interaction between ZnxFe3–xO4 and the SiO2 network. The ZnxFe3–xO4/SiO2 nanocomposites had a spherical morphology and a particle size of approximately 36.99–41.79 nm. The nanocomposites displayed an S-like pattern, indicating superparamagnetic characteristics. The saturation magnetization exhibited a non-linear trend over the range 1.64–4.21 emu/g, attributed to Zn2+ substitution in the crystal lattice and particle size. The drug carrier performance of the nanocomposites was achieved for x = 0.1 with loading (above 95%) and release (above 64%). Doxorubicin molecules were considered to be adsorbed onto ZnxFe3–xO4/SiO2 nanocomposites through electrostatic interactions, hydrogen bonding, and π–π interactions. Therefore, the ZnxFe3–xO4/SiO2 nanocomposites show great promise as drug delivery agents for inhibiting cancer cell proliferation.