Sol\u2013gel auto-combustion\xa0mediated cobalt ferrite nanoparticles: a potential material for antimicrobial applications

Rashmi P. Sharma,Ambadas S. Kadam,Siddheshwar D. Raut,Ramjan M. Mulani,Rajaram S. Mane

doi:10.1007/s40089-019-0268-4

Abstract

In the era of nanotechnology, nanoparticles (NPs) of metals and metal oxides/chalcogenides are widely been used in medical applications where antibiotic-resistant microorganisms become a serious threat to the human health. Cobalt ferrite (CoFe2O4) NPs, synthesized by a simple and cost-effective sol–gel auto-combustion method are envisaged for in vitro antimicrobial activities against Gram-positive bacteria (Bacillus subtilis; Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli; Pseudomonas aeruginosa). The structure, morphology, elemental analyses and surface area of CoFe2O4 NPs are initially screened. The antimicrobial efficiency of CoFe2O4 NPs is found to be optimum against the Gram-negative bacteria Escherichia coli (15 mm). In addition, membrane leakage assays performed to evaluate the intracellular cytoplasmic leakage with CoFe2O4 NPs demonstrate the ability to destroy the bacterial membrane integrity, confirming their antimicrobial potential.

Highlights

In post-antibiotic era, low antibiotic susceptibility of pathogenic bacteria is still continuing worrisome situation
The size, surface area and the morphology of the obtained ferrites can be engineered by changing the annealing temperature and synthesis conditions [25, 26]
In first stage, CoFe2O4 NPs were synthesized by a cost-effective sol–gel auto-combustion method, air-annealed at 500 °C for 5 h and characterized for their structure, morphology and surface area measurements

Summary

Introduction

In post-antibiotic era, low antibiotic susceptibility of pathogenic bacteria is still continuing worrisome situation. On the basis of above experimentation history, present work deals with the synthesis and antibacterial activity measurements of C oFe2O4 NPs. In first stage, CoFe2O4 NPs were synthesized by a cost-effective sol–gel auto-combustion method, air-annealed at 500 °C for 5 h and characterized for their structure, morphology and surface area measurements. In first stage, CoFe2O4 NPs were synthesized by a cost-effective sol–gel auto-combustion method, air-annealed at 500 °C for 5 h and characterized for their structure, morphology and surface area measurements These CoFe2O4 NPs were applied in antibacterial efficiency on selected pathogen using agar well-diffusion technique and studied for membrane integrity by membrane leakage assay. The membrane leakage assay was performed by estimating the amount of reducing sugars and proteins from test bacterial membrane In this assay different volume of Mueller–Hinton broth, NPs, and test pathogens were added into 10 mL culture with final concentration of 100 μg/mL CoFe2O4 NPs and 109 cfu/mL test pathogens. 58.52% atomic compositions of the Co, Fe and O elements were in good agreement to 1:2:4 ratios so as to obtain the chemical stoichiometry of CoFe2O4

Results and discussion

Conclusion

Compliance with ethical standards