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

Abstract

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.

Development of Human Host Defense Antimicrobial Peptide-Conjugated Biochar Nanocomposites for Combating Broad-Spectrum Superbugs

“…As shown in Figure 1D, the FTIR spectra from the antimicrobial peptide-attached biochar-based nanocomposite show the presence of −amide-A, −OH, −amide-I, −CC−, amide-II, and amide-III. 18,19,[23][24][25][26][27][28]33 The experimentally observed different amide bands in the XPS data and FTIR spectra indicate that biochar is attached with different peptides in nanocomposites.…”

“…As shown in Scheme 1B, for this purpose, initially, carboxyl groups from biochar were activated using 1-ethyl-3(3-(dimethylamino)-propyl)carbodiimide•HCl (EDC) and N-hydroxysuccinimide (NHS) coupling agents for 30 min. 18,19,33 After that, different antimicrobial agents, such as HNP-1, hBD-1, and LL-37, were added at different weight ratios under stirring. In the next step, we have continued the process for 24 h. After that, we have performed centrifugation at 10 000 rpm for 30 min, followed by decantation.…”

“…In the next step, we have performed filtration of superbug-infected water sample using α-defensin human neutrophil peptide-1, human β-defensin-1, and human cathelicidin LL-37-attached biocharbased nanocomposites. After separation of MRSA, CRE E. coli, KPN, and VRE superbugs via filtration, we have used the colony plating technique on lysogeny broth (LB) agar 18,19,33 as well as reverse transcription polymerase chain reaction (RT-PCR) techniques 18,19,33 for finding the removal efficiency of different drug-resistant bacteria using α-defensin human neutrophil peptide-1, human β-defensin-1, and human cathelicidin LL-37-attached biochar-based nanocomposites. Experimental details are discussed in the Supporting Information.…”

The Role of New Inorganic Materials in Composite Membranes for Water Disinfection

“…0.20 wt %) into PVDF ultrafiltration membranes increased the water permeability by 96.4% compared to the pristine membrane, while the tensile strength also was raised by 123% [37]. In contrast, Pramanik et al [38] used GO and its plentiful oxygen-containing groups, and the functional groups of catechols and amines from polydopamine nanoparticles, for the removal of heavy metal decontamination. Importantly, ε-poly-L-lysine, as a natural antimicrobial peptide, was also strategically attached to the composite nanoparticles for the elimination of bacteria.…”

“…To date, most of the studies have evaluated the disinfection activity of composite membranes and composite materials using model water solutions; it is recommended to start the testing of hybrid composites using real complex aqueous solutions since few reports have used natural complex water systems (e.g., natural water coming from rivers, lakes, and taps) [38,43,76].…”