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.

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Uranium is a chemically toxic and radioactive heavy metal. Depleted uranium (DU) is the byproduct of the uranium enrichment process, with a majority of U as uranium-238, and a lower content of the fissile isotope uranium-235 than natural uranium. Uranium-235 is mainly used in nuclear reactors and in the manufacture of nuclear weapons. Exposure is likely to have an impact on humans or the ecosystem where military operations have used DU. Yuma Proving Ground in Arizona, USA has been using depleted uranium ballistics for 36 years. At a contaminated site in the Proving Grounds, soil samples were collected from the flat, open field and lower elevated trenches that typically collect summer runoff. Spatial distribution and fractionation of uranium in the fields were analyzed with total acid digestion and selective sequential dissolution with eight operationally defined solid-phase fractions. In addition to uranium, other trace elements (As, Ba, Co, Cr, Cu, Hg, Mo, Nb, Pd, Pb, V, Zn, Zr) were also assessed. Results show that the trench area in the testing site had a higher accumulation of total U (12.4%) compared to the open-field soil with 279 mg/kg U. Among the eight solid-phase components in the open-field samples, U demonstrated stronger affinities for the amorphous iron-oxide bound, followed by the carbonate bound, and the residual fractions. However, U in the trench area had a stronger binding to the easily reducible oxide bound fraction, followed by the carbonate-bound and amorphous iron-oxide-bound fractions. Among other trace elements, Nb, As, and Zr exhibited the strongest correlations with U distribution among solid-phase components. This study indicates a significant spatial variation of U distribution in the shooting range site. Fe/Mn oxides and carbonate were the major solid-phase components for binding U in the weapon test site.

Fruit based nanosystem can identify triple negative breast cancer cells.