Biogenic Synthesis of Iron Oxide Nanoparticles Using Enterococcus faecalis: Adsorption of Hexavalent Chromium from Aqueous Solution and In Vitro Cytotoxicity Analysis

Abstract

The biological synthesis of nanoparticles is emerging as a potential method for nanoparticle synthesis due to its non-toxicity and simplicity. In the present study, a bacterium resistant to heavy metals was isolated from a metal-contaminated site and we aimed to report the synthesis of Fe3O4 nanoparticles via co-precipitation using bacterial exopolysaccharides (EPS) derived from Enterococcus faecalis_RMSN6 strains. A three-variable Box–Behnken design was used for determining the optimal conditions of the Fe3O4 NPs synthesis process. The synthesized Fe3O4 NPs were thoroughly characterized through multiple analytical techniques such as XRD, UV-Visible spectroscopy, FTIR spectroscopy and finally SEM analysis to understand the surface morphology. Fe3O4 NPs were then probed for the Cr(VI) ion adsorption studies. The important parameters such as optimization of initial concentration of Cr(VI) ions, effects of contact time, pH of the solution and contact time on quantity of Cr(VI) adsorbed were studied in detail. The maximum adsorption capacity of the nanoparticles was found to be 98.03 mg/g. The nanoparticles could retain up to 73% of their efficiency of chromium removal for up to 5 cycles. Additionally, prepared Fe3O4 NPs in the concentration were subjected to cytotoxicity studies using an MTT assay. The investigations using Fe3O4 NPs displayed a substantial dose-dependent effect on the A594 cells. The research elucidates that the Fe3O4 NPs synthesized from EPS of E. faecalis_RMSN6 can be used for the removal of heavy metal contaminants from wastewater.

Biosynthesis and Characterization of Iron Oxide Nanoparticles and their Antibacterial Activity

“…XRD analysis resulted that the distinct peaks were found at 26, 33, 35, 55 and 62 • accounting for crystal planes 012, 104, 113, 214 and 300, respectively. These characteristic peaks are in agreement with standard diffraction data JCPDS: 34-0665 of hematite and correspond to face-centered cubic (fcc) symmetry (Asuha et al, 2009;Samuel et al, 2021). In addition, earlier reports found that Fe3O4 nanoparticle crystallinity was not changed by the chitosan coating (Li et al, 2008).…”

Zinc/Cerium-Substituted Magnetite Nanoparticles for Biomedical Applications

“…Iron oxides are a group of naturally occurring materials with immense potential within the biomedical area owing to the iron component, which is an essential element within the organism [ 1 ]. Among them, magnetite nanoparticles are the first generation of clinically approved nanomaterials that have been intensively used for their superparamagnetic properties in novel and efficient biomedical applications [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Besides the possibility to adsorb and immobilize large quantities of bioactive compounds [ 1 ], magnetite nanoparticles are widely known for their intrinsic antioxidant [ 10 ], antimicrobial [ 11 ], and anticancer [ 12 ] properties, which can be potentiated through hyperthermia effects [ 11 ].…”

Acrylonitrile adducts: design, synthesis and biological evaluation as antimicrobial, haemolytic and thrombolytic agent

“…Samuel et al . 12 developed simple one-pot method and promoted the biological synthesis of nanoparticles as a promising method for nanoparticle synthesis. They have developed a hybrid polymer composite of lithocholic acid (LCA), zinc pyrithione (Zn) and cinnamaldehyde (Cn) (named as LCA–Zn–Cn) which displays potent antibacterial/antibiofilm activity 13 .…”

“…They have developed a hybrid polymer composite of lithocholic acid (LCA), zinc pyrithione (Zn) and cinnamaldehyde (Cn) (named as LCA–Zn–Cn) which displays potent antibacterial/antibiofilm activity 13 . Moreover, they have biosynthesized iron oxide nanoparticle (Fe 3 O 4 NPs) and showed its dual benefits as effective adsorbent for removal of heavy metal ion from wastewater and as biomedical agents 12 .…”

“…Loading of the nanocomposites was carried out through ecofriendly method 8,9 and incorporation of the nanocomposites enhances the antimicrobial, antifungal, antiviral, antioxidant and anticancer activities 10,11 . Samuel et al 12 developed simple one-pot method and promoted the biological synthesis of nanoparticles as a promising method for nanoparticle synthesis. They have developed a hybrid polymer composite of lithocholic acid (LCA), zinc pyrithione (Zn) and cinnamaldehyde (Cn) (named as LCA-Zn-Cn) which displays potent antibacterial/ antibiofilm activity 13 .…”