Green synthesis of copper nanoparticles and their formulation into face masks: An antibacterial study

Abstract

AbstractWe report the facile ultrasound‐assisted synthesis of copper nanoparticles (CuNPs) using blueberries extract (Vaccinium corymbosum) under environmental conditions and their incorporation into face masks as an effective antibacterial additive. For this purpose, the hydro‐alcoholic blueberry extract was combined 1:1 with a metal precursor (CuSO4). The chemical reduction process was improved by ultrasound‐assisted method for 30 min, obtaining semispherical CuNPs ranging ca. 3–12 nm employing TEM analysis. Freshly synthesized CuNPs were characterized by UV–Vis spectra, demonstrating the characteristic SPR absorption band at 535 nm. XRD patterns of CuNPs powder revealed the crystalline structure FCC of CuNPs, without CuO/CuO2 species. Antibacterial activity (AA) of biosynthesized CuNPs was evaluated against two high virulence pathogens: Gram‐positive Staphylococcus aureus and Gram‐negative Pseudomonas aeruginosa, after 1 and 3 h of contact, showing a MIC of 200 μg/ml, and a CMB of 400 μg/ml. To validate the potential biological application of CuNPs were incorporated into PES fibers and deposited at the surface of non‐woven face masks against Escherichia coli and the airborne bacteria S. aureus, demonstrating their high antibacterial capacity after 24 h. Our results represent a facile and green method to produce high amounts of antibacterial CuNPs (yield ca. 1 g/L of reaction), with potential application as an effective additive for antimicrobial coatings formulation.