Manganese ferrite graphene nanocomposite synthesis and the investigation of its antibacterial properties for water treatment purposes

Abstract

<jats:p>The main objective of this study was to synthesize a nanocomposite using graphene and manganese ferrite nanoparticles (MnFe2O4-G) and to evaluate its antibacterial activity for water treatment purposes. Its morphological characteristics were evaluated by instrumental techniques, such as scanning electron microscopy and transmission electron microscopy. The characterization results indicated that the nanocomposite presented nanoparticles of approximately 25 nm well dispersed in transparent and large (14 μm) graphene nanosheets. The antibacterial activity was evaluated in a batch experiment using a concentration of 40 μg mL-1 of nanocomposite (MnFe2O4-G, bare MnFe2O4 nanoparticles or graphene oxide), 1x105 CFU mL-1 of Escherichia coli, and 8 h of contact time at room temperature. The highest antibacterial capacity was observed for the hybrid nanocomposite (91.91%), due to the synergic effect of graphene and MnFe2O4 nanoparticles. Various mechanisms were proposed to explain the effective antibacterial activity of MnFe2O4-G, such as wrapping, oxidative stress, sharp-edge cutting effect, among others. The results showed that MnFe2O4-G is a potential alternative in water treatment processes as an antibacterial agent.</jats:p>

Chitosan-Functionalized Hydroxyapatite-Cerium Oxide Heterostructure: An Efficient Adsorbent for Dyes Removal and Antimicrobial Agent

“…Obviously, less bacteriostatic outcome was found at small amounts of HAP against E. coli , nonetheless improved activity was found with CS-HAP-CeO 2 heterostructure. The greater activity of CS-HAP-CeO 2 heterostructure was endorsed to morphological topographies with large surface [ 68 ] and synergism [ 69 ] between HAP and CeO 2 . The coating of CS also augmented in antimicrobial performance.…”

Manganese Ferrite–Hydroxyapatite Nanocomposite Synthesis: Biogenic Waste Remodeling for Water Decontamination

“…Evidently, an insignificant bacteriostatic effect was observed at a low concentration with HAP against E. coli , but better performance was observed with nanocomposites against S. aureus . The enhanced activity of the HAP-MnFe 2 O 4 nanocomposite was credited with morphological features with enlarged surfaces [ 35 ] as well as a synergism [ 36 ] between HAP and MnFe 2 O 4 . The hypothesis could be that, at first, HAP and HAP-MnFe 2 O 4 nanocomposite probably interacted with the bacterial wall and membrane, later on dispersing to the interior of the cell, instigating leakage by distracting the cell’s contents.…”

“…Convincingly, their deadly impact on bacterial cells is perhaps owed to these mechanisms, for instance impairment of the bacterial cytoplasmic membrane, protein disintegration and destruction to DNA [ 37 ], as aforementioned. Furthermore, the electron transfer taking place on a facet of HAP-MnFe 2 O 4 can produce free oxidative radicals, which are lethal to bacteria [ 36 ] ( Scheme 1 ).…”