Biosynthesis of cobalt oxide nanoparticles using bacteria
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Fateme Momen Eslamieh-ei,1 Mansour Mashreghi,2 Maryam Moghaddam Matin,3,*
1. Ferdowsi university of Mashhad
2. Ferdowsi university of Mashhad
3. Ferdowsi university of Mashhad
- Introduction: Nowadays, more specific methods for cancer treatment, including gene therapy and the application of nanoscience and drug-nanoparticle compounds which usually lead to a better outcome, have attracted considerable attention. Nanotechnology is used to diagnose cancer at early stages, design a drug delivery system by targeting the nano-drug combination for cancer cells, and reduce the cytotoxicity to normal cells. Cobalt oxide is one of the most potent natural antioxidants and exists in two forms: Co3O4 and CoO. Various applications of these nanoparticles in medicine, such as drug delivery systems, toxicity to cancer cells, and antibacterial properties, have been studied and analyzed. Synthesis of cobalt oxide nanoparticles can be done by various methods, including chemical, physical, physicochemical, and biosynthetic methods. So far, the synthesis of green cobalt oxide nanoparticles has been done using plant extracts, fungi, and bacteria.
- Methods: In brief, luminescence Vibrio bacteria were grown in Sea Water Complete (SWC) medium at 28°C for 2 days. After centrifugation of cultured bacteria, 100 ml of sonicated culture was mixed with 50 ml of 25 mM aqueous cobalt nitrate hexahydrate filtrates in a 250 ml flask and incubated at 90°C for two hours. The successful synthesis of cobalt oxide nanoparticles (Co3O4NPs) was determined based on the color change to purple. At the next step, biosynthesized cobalt oxide nanoparticles were annealed at 500°C for 2 hours. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were carried out for nanoparticles characterization.
- Results: The XRD results illustrated the success of biosynthesized Co3O4NPs and the diffraction peaks at 2θ values of 19o and 36o. The FTIR spectra characterized the functional groups in Co3O4NPs; the peaks were observed at 3445, 2924, 1010, 605, and 561 cm-1. The 3445 and 2924 cm-1 peaks could be due to –OH stretching from polysaccharides and C–H stretching of alkanes, respectively. The peaks at 1010 and 605 cm-1 could be assigned to (C–O) of the alkoxy and CH2 groups, respectively. 561 cm-1 peak might be due to cobalt oxide NPs. The results of SEM indicated that the biologically synthesized cobalt oxide nanoparticle is spherical with a 70 nm diameter. The results of EDS analysis indicated that the main elements refer to the peaks of cobalt and oxygen to be 38 and 36%, respectively, in the biosynthesized Co3O4NPs.
- Conclusion: This study investigates a biological method to synthesize cobalt oxide nanoparticles using a luminescent Vibrio bacterium. The properties of Co3O4 NPs were characterized by XRD, FTIR, SEM, and EDS. Biosynthesis of cobalt oxide nanoparticles from luminescence Vibrio is considered a novel and ecofriendly method.
- Keywords: Cobalt oxide nanoparticle, Biological synthesis, Luminescent bacterium.
