Interaction of nickel ferrite nanoparticles with nucleic acids.

In this article, we introduced an electrochemical biosensor employing graphite electrodes (GE) decorated with Nickel ferrite (NiFe2O4) nanoparticles for nucleic acid detection. NiFe2O4 nanoparticles in a narrow size distribution were synthesized with co-precipitation technique. Their chemical and crystallographic properties were characterized with FTIR and X-ray spectroscopies. Nanoparticle size distribution and hydrodynamic diameter were determined with particle size analyzer. Elemental content and purity of nanoparticles were analyzed with EDX analysis. Our analyses showed a diameter of ~10 nm for NiFe2O4 nanoparticles. Electrochemical properties of NiFe2O4 nanoparticles were examined with different analysis methods. Conductivity properties of NiFe2O4 nanoparticles were investigated with Cyclic Voltammetry (CV), which confirmed that nanoparticles on GE surface have a high surface area and conductivity. More importantly, in this article, the interactions between NiFe2O4 nanoparticles and double stranded DNA (dsDNA), single stranded DNA (ssDNA), and RNA were for the first time examined using Differential Pulse Voltammetry (DPV), CV, and Electrochemical Impedance Spectroscopy (EIS). Oxidation peak currents of NiFe2O4 nanoparticles and guanine bases of dsDNA, ssDNA, and RNA showed that NiFe2O4 nanoparticles effectively interacts with nucleic acids via an electrostatic mode.