ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis and characterization of hydrothermally synthesized superparamagnetic APTS–ZnFe₂O₄ nanoparticles: DNA binding studies for exploring biomedical applications

Neelam Yadav, Amit Singh, and Mahima Kaushik

Nano-Bioconjugate Chemistry Lab, Cluster Innovation Centre, University of Delhi, Delhi, India

E-mail: mkaushik@cic.du.ac.in

Received: 22 April 2019  Accepted: 4 October 2019

Abstract:

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 (M_s) 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.

Graphic Abstract:

Keywords: APTS-modified ZnFe2O4 nanoparticles; Superparamagnetic nanoparticles; Hydrothermal autoclave synthesis of nanoparticles; One-pot synthesis of nanoparticles; DNA–nanoparticles interaction

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-019-00953-0

Chemical Papers 74 (4) 1177–1188 (2020)