Antibacterial properties of copper-substituted cobalt ferrite nanoparticles synthesized by co-precipitation method

- CuxCo1−xFe2O4 nanoparticles (0 ≤ x ≤ 1) were synthesized by a co-precipitation method.
- Cu substitution caused decrease of particle size and crystallinity.
- Substitution of Co with Cu improved the antibacterial activity against E. coli.

Controlled growth and careful characterization of cobalt ferrite nanoparticles for antibacterial applications are challenging. Copper-substituted cobalt ferrite nanoparticles (CuxCo1−xFe2O4), where x = 0.0, 0.3, 0.5, 0.7 and 1.0, were synthesized using an economical and simple co-precipitation technique. The crystal structure and antibacterial properties of the samples as a function of Cu-substituted content were systematically studied. With increasing Cu concentration, the nanoparticle size decreased from ∼30 to ∼20 nm. The Fourier transform infra-red spectra exhibit two prominent fundamental absorption bands, at ∼595 and 419 cm−1. These bands correspond to intrinsic stretching vibrations of metals at tetrahedral and octahedral sites, respectively. The Raman scattering results reveal that increasing the Cu content enhances the local disorder at both tetrahedral and octahedral sub lattices. The results indicate that the substitution of Co with Cu in cobalt ferrite nanoparticles strongly influences the microstructure, crystal structure, and particle diameter, and also improves the antibacterial properties.

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