Interaction between Copper Oxide Nanoparticles and Amino Acids: Influence on the Antibacterial Activity

Abstract

The increasing concern about antibiotic-resistance has led to the search for alternative antimicrobial agents. In this effort, different metal oxide nanomaterials are currently under investigation, in order to assess their effectiveness, safety and mode of action. This study focused on CuO nanoparticles (CuO NPs) and was aimed at evaluating how the properties and the antimicrobial activity of these nanomaterials may be affected by the interaction with ligands present in biological and environmental media. Ligands can attach to the surface of particles and/or contribute to their dissolution through ligand-assisted ion release and the formation of complexes with copper ions. Eight natural amino acids (L-Arg, L-Asp, L-Glu, L-Cys, L-Val, L-Leu, L-Phe, L-Tyr) were chosen as model molecules to investigate these interactions and the toxicity of the obtained materials against the Gram-positive bacterium Staphylococcus epidermidis ATCC 35984. A different behavior from pristine CuO NPs was observed, depending on the aminoacidic side chain. These results were supported by physico-chemical and colloidal characterization carried out by means of Fourier-Transform Infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo-Gravimetric Analysis (TGA), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and light scattering techniques (Dynamic Light Scattering (DLS), Electrophoretic Light Scattering (ELS) and Centrifugal Separation Analysis (CSA).

Broadband Microwave Signal Dissipation in Nanostructured Copper Oxide at Air‐film Interface**

“…Cu‐based nanoparticles may undergo profound charge‐transfer transformations, under different biological and environmental conditions, which can induce significant changes in their structural and physicochemical properties and in turn, affect their toxicity. For example, depending on the amino‐acidic side chain, ligands attach to the surface of CuO nanoparticles and/or alter their properties [35]. In principle, like the paper‐supported MO for sensing application discussed above, non‐contact BDS has the potential for monitoring the quality and capacity of such MO‐impregnated PPE, as well as identify the pathogens the wearer of the PPE has been exposed to.…”

Synthesis and Characterization of New Multifunctional Self-Boosted Filters for UV Protection: ZnO Complex with Dihydroxyphenyl Benzimidazole Carboxylic Acid

“…The Zn content of each Zn base material was measured by means of ICP-MS (NexION 350D, Perkin Elmer), after a microwave acidic mineralization using a Discover SP-D oven (CEM Corporation). According to Badetti and co-workers [28], about 20 mg of dry samples was treated with a mixture of ultrapure H 2 O 2 and HNO 3 in a 1:2 ratio. The heating program used for the acid digestion was: T MAX = 170 • C, ramp time = 5 min, hold time = 2 min, power = 300 W. Afterwards, the samples were cooled down for 30 min at room temperature, properly diluted, and analyzed by ICP-MS.…”

Novel PVA nanocomposite films: Synthesis, structure, optical and photocatalytic properties evaluation.

“…Among the twenty amino acids Asp is unique properties, due to the presence of side chain containing additional carboxyl group resulted negative charge. Researcher demonstrated the strong formation of complex between CuO NPs and Asp is documented [62]. Literature reported semiconducting properties of Asp is alone 5.02 eV and also exhibit very good hydrophilic property which helps potential removal dye is established [63][64][65].…”