Abstract
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.
Highlights
Water is an essential resource for all beings
Similar structures were found in micrographs obtained in our previous work (Yamaguchi et al, 2016) and by Yao et al (2014), who used a similar methodology to that employed in this work
The size of MnFe2O4 nanoparticles can be confirmed by TEM and scanning electron microscopy (SEM) micrographs (Figure 2), showing an average particle size of 25 nm
Summary
Water is an essential resource for all beings. Unsafe drinking water still constitutes a major burden on public health in developing countries. Diseases related to drinking water contamination lead to millions of deaths every year and diarrhea remains a major cause of child deaths. The main health risk is ingestion of water contaminated with feces that contains pathogens that cause infectious diseases such as cholera and other diarrheal diseases, dysenteries and enteric fevers (Liu et al, 2012a). The development of novel and efficient antibacterial agents to control and prevent contamination by pathogenic microorganisms in water is vital for human health and well-being. Antibacterial nanomaterials provide great opportunities to develop next-generation sustainable water-disinfection technologies. Among all the antibacterial nanomaterials, graphene-based nanomaterials have emerged recently as a novel green broad-spectrum antibacterial material, with a severe cytotoxic effect on bacteria, fungi, and plant pathogens, with little resistance and tolerable cytotoxic effect on mammalian cells (Hegab et al, 2016; Ji et al, 2016)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
