One-dimensional ordered growth of magneto-crystalline and biocompatible cobalt ferrite nano-needles

In this letter, we have reported a novel synthesis of CoFe2O4 nano-needles by a co-precipitation method using precursors of ferric chloride and cobalt nitrate at 80 °C. The structural and magnetic properties of as-grown needle-like CoFe2O4 nanostructures exhibit cubic spinel structure. CoFe2O4 nano-needles have an average diameter of 15 nm with an aspect ratio of 30:50, which was depicted by High-resolution transmission electron microscopy (HRTEM). Superconducting Quantum Interference Device (SQUID) confirmed the property of superparamagnetism. The magnetic measurement illustrated that the coercivity (Hc) of CoFe2O4 nano-needles increased from −145.84 Oe at 5 K to −25.38 Oe at 312 K. The cell viability studies of CoFe2O4 nano-needles were performed in the concentration range of 5-1000 µg/ml on L6 (Skeletal muscle cell lines) and Hep-2 (Larynx carcinoma) cells using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. There was more than 50% cell viability for both the cell lines, but Hep-2 cells were more prone to killing as compared to L6 cells. Such biocompatible nanostructures can be used as drug-delivery systems for cancer therapeutics.