Nanosized mixed transition metal oxides or spinel ferrites are the most rivet class of nanomaterials due to their exceptional optical, structural and most importantly superior magnetic properties. These properties stored in ZnFe2O4 make it an apt contender to offer incomparable magnetic nanodevices for biomedical applications. These applications demand high magnetization, controllable size/size distribution and an appropriate, biocompatible non-toxic surface coating. Therefore, the aim of this study was to synthesize (3-aminopropyl)triethoxysilane (APTS) modified ZnFe2O4 nanoparticles via hydrothermal method and to investigate interaction of synthesized nanoparticles with calf thymus DNA using various physicochemical techniques. Structural characterization of particles was done using XRD, FTIR, FE-SEM, VSM, zeta potential and UV–Visible spectroscopy. Average grain size of APTS-coated ZnFe2O4 nanoparticles as calculated from XRD was found to be nearly 8 nm. A lower saturation magnetization (Ms) value in case of APTS–ZnFe2O4 over uncoated ZnFe2O4 reveals successful addition of non-magnetic material (APTS) to ZnFe2O4 nanoparticles. Binding studies of nanoparticles with DNA were performed using UV–Visible, fluorescence and circular dichroism spectroscopy. Physicochemical studies of this nano-bioconjugate system reveal significant structural and conformational alterations in calf thymus DNA on external contact of nanoparticles. On correlation, all studies suggested that interaction between nanoparticles and DNA is mainly governed by electrostatic interaction. These findings might provide insights into the study of these nanoparticles in drug delivery and for designing of magnetic nanodevices for biomedical applications.
Keywords: APTS-modified ZnFe2O4 nanoparticles; Superparamagnetic nanoparticles; Hydrothermal autoclave synthesis of nanoparticles; One-pot synthesis of nanoparticles; DNA–nanoparticles interaction