Biosynthesis of a tri‐metallic nanoalloy for magnetic and biomedical applications

Abstract

The tri‐metallic magnetic nanoalloy synthesized via the eco‐friendly procedure discussed here contains cobalt (Co), nickel (Ni), and zirconium (Zr) metals in a 3:1:1 M ratio (Co3O4.NiO.ZrO2 nanoalloy). Two different plant extracts which are rich in biologically active compounds from Spermacoce hispida and Vernonia cinereum were combined to get a multispecies nanoalloy with magnetic properties and medicinal values. The Fourier transform infrared, X‐ray diffraction, and transmission and scanning electron microscopes analyses confirmed the spherical shape of the bioinspired Co3O4.NiO.ZrO2 nanoalloy. The average size of our nanoalloy was 32 nm, but the individual nanoparticles are between 21 and 73 nm in size. A vibrating sample magnetometer study of the magnetic characteristics of the nanoalloy reveals strong saturation magnetization (12.42 emu/g), low retentivity (Mr), and low coercivity (Hc) (282.36 Oe). The higher saturation magnetization in nanoalloy is attributed to their larger particle size, a high degree of crystalline structure, and slight external spinning deformation. The low coercive field (Hc) value reveals the unique soft nature of our nanoalloy. The disc diffusion study confirms that a 6.3 μg/mL solution of the nanoalloy kills almost 96% of the harmful bacteria like Bacillus subtilis (29 mm), Bacillus cereus (26 mm), and Escherichia coli (21 mm). It shows a moderate effect of 85% killing factor against Staphylococcus albus (17 mm), Pseudomonas aeruginosa (13 mm), and Klebsiella pneumoniae (15 mm) bacteria.