Green and chemical synthesis of Cu₂O nanoparticles for antibacterial functionalization of textiles: a comparative study against Escherichia coli strains

This study evaluates the synthesis of cuprous oxide (Cu_2O) nanoparticles via biogenic and chemical methods, employing Myrciaria dubia juice and ascorbic acid as reducing agents, respectively. The biogenic synthesis yielded nanoparticles with an average size of 10 ± 2.22 nm, whereas the chemical method produced particles averaging 75 ± 2.8 nm. The nanoparticles were incorporated into textiles (70% cotton, 30% polyester) through in situ and post-synthesis functionalization methods. The functionalized textiles exhibited significant antibacterial efficacy against Escherichia coli ATCC 25922, with inhibition rates exceeding 99.9%: 99.98% for the chemical post-synthesis method, 99.94% for the biogenic post-synthesis method, and 99.90% for the biogenic in situ method. However, no significant antibacterial effect was observed against extended-spectrum β-lactamase (ESBL)-producing E. coli strains. These findings highlight the critical role of nanoparticle size and functionalization method in antimicrobial effectiveness, underscoring the potential of green synthesis for the development of sustainable antibacterial textiles. IMPORTANCE This article demonstrates a differential response to copper oxide nanoparticles between an antibiotic-sensitive Escherichia coli strain and another strain of E. coli resistant to antibiotics, such as extended-spectrum beta-lactamases. Therefore, it could be thought that resistance to the effects of copper oxide nanoparticles could be related to antibiotic resistance.