Composites Composed of Polydopamine Nanoparticles, Graphene Oxide, and ε-Poly-l-lysine for Removal of Waterborne Contaminants and Eradication of Superbugs

The World Health Organization (WHO) estimates that 30% people in the world lack access to safe drinking water due to the presence of toxic waterborne contaminants, which kills more than 7.6 million children every year. Marine mussels secure themselves in the environment via foot proteins containing 3,4-dihydroxy-l-phenylalanine (DOPA) and lysine amino acids. Inspired by mussel surface chemistry, in the current paper, we report the development of novel composite nanoparticles via functionalization of polydopamine nanoparticle with graphene oxide and ε-poly-l-lysine, which can be used in decontamination of toxic waterborne contaminants and disinfection of drug resistance pathogens from environmental water samples. Reported composite nanoparticles with specific surface area 410 m2g–1, pore volume 0.620 cm3 g–1, and pore size between 2 and 130 nm have been used as channels for water passage and captured toxic metals as well as drug resistant pathogens. The surface oxygen-containing groups from GO and the functional groups of catechols and amines in PD nanoparticles have been used as active sites for decontamination of heavy metals ions. ε-Poly-l-lysine, a natural antimicrobial peptide, has been attached to the composite nanoparticle for killing of superbugs captured by the membrane. Reported data demonstrated that composite nanoparticles can be used for efficient separation of several heavy toxic metals such as Cr6+, Pb2+, Cu2+, Hg2+, and Zn2+ from environmental water samples. The same membrane also can be used for 100% separation and eradication of different superbugs such as β-lactamase (ESBL)-producing Klebsiella pneumoniae (KPN) and methicillin-resistant Staphylococcus aureus (MRSA). Possible mechanisms for water contaminant separation and disinfection of superbugs using composite nanoparticles are discussed.