Effect of the Concentration and the Type of Dispersant on the Synthesis of Copper Oxide Nanoparticles and Their Potential Antimicrobial Applications

Abstract

The bactericidal properties of copper oxide nanoparticles have growing interest due to potential application in the medical area. The present research investigates the influence of sodium dodecyl sulfate (SDS) and poly­(vinylpyrrolidone) (PVP) on the production of copper oxide nanoparticles prepared from copper sulfate (CuSO4) and sodium borohydride (NaBH4) solutions. Different analytical techniques were used to determine the crystal nature, mean size diameter, and surface morphology of the copper oxide nanoparticles. The X-ray diffraction (XRD) patterns showed formation of nanoparticles of cuprite (Cu2O) and tenorite (CuO) when PVP and SDS were added at the beginning of the reaction. In fact, when the Cu/PVP ratio was 1.62, Cu2O nanoparticles were obtained. In addition, nanoparticles of CuO were synthesized when the Cu/PVP ratios were 0.54 and 0.81. On the other hand, a mixture of copper oxides (CuO and Cu2O) and cuprite (Cu2O) was obtained when PVP (Cu/PVP = 0.81 and 1.62) and SDS (Cu/SDS = 0.90) were added 30 min after the beginning of the reaction. Transmission electron microscopy (TEM) images show agglomerated nanoparticles with a size distribution ranging from 2 to 60 nm, while individual particles have sizes between 4.1 ± 1.9 and 41.6 ± 12.8 nm. The Kirby–Bauer method for the determination of antibacterial activity shows that small CuO (4.1 ± 1.9 nm) and Cu2O (8.5 ± 5.3 nm) nanoparticles inhibit the growth of Escherichia coli, Staphylococcus aureus MRSA, S. aureus and Pseudomonas aeruginosa bacteria. The antibacterial test of cotton fabric impregnated with nanoparticles shows positive results. The determination of the optimal ratio of copper oxide nanoparticles per cm2 of fabric that are able to exhibit a good antibacterial activity is ongoing.

Structural and antibacterial properties of copper oxide nanoparticles: a study on the effect of calcination temperature

“…For E. coli, more CuO nanoparticles concentration was required to inhibit the bacteria. Similar results were reported by Guzman et al [21], where they observed that CuO nanoparticles with particle size range of 4.1 ± 1.9 nm were more effective in inhibiting both S. aureus and E. coli, with the results being more pronounced to S. aureus. From the above studies, it is not conclusive why the CuO nanoparticles are better in inactivating gram positive bacteria with higher activity compared to gram negative bacteria.…”

“…It is widely acknowledged that the higher the surface area per unit mass, the more active and effective the material becomes. In addition to the surface characteristics of the material, the release of ions plays a major role [19,21,53]. The exact bacterial mechanism of CuO nanoparticles is still not yet fully understood, it emerges that several mechanisms have been suggested which include (1) the immediate interaction of CuO nanoparticles and bacterial surfaces, consequently damaging the cell wall of the bacteria.…”

“…The nanoparticles are also considered to be highly effective on resistant strains of pathogenic bacteria and are of low toxicity which of course depends on several factors. The high antibacterial activity they possess is because of their large surface area and small particle sizes that influence the material to strictly interact with the bacteria cell membranes, hence, causing cell death [14][15][16][17][18][19][20][21][22]. These properties therefore open new application routes for CuO nanoparticles to be used in other crucial applications such as food packaging, healthcare and water treatment.…”

Copper oxide nanoparticles doped with lanthanum, magnesium and manganese: optical and structural characterization

“…The modified chemical reduction method proposed by Badawy et al [ 54 ] was used for the synthesis of Cu 2 O Nps [ 55 , 56 ]. For the synthesis, ethanolic solutions of sodium hydroxide (20 mM), Mg nitrate (20 mM), Mn nitrate (20 mM) and La nitrate (20 mM) were used.…”

Preparation of CuO loaded cation exchange resin composites and its degradation of polyacrylamide aqueous solution

“…This indicates that the addition of dispersant does not achieve the expected effect and does not optimize the formation of the product, which may be related to many factors such as the amount of dispersant used, the amount of OH À in the solution, and the amount of Cu 2+ loaded on the resin. 28 In later research, the systematic experiments and the detailed analysis will be conducted.…”