Antimicrobial performance and congo red adsorption of plant extract derived copper oxide nanoparticles

Artocarpus altilis stem extract derived copper oxide nanoparticles (CuO BSNPs) was synthesized and evaluated for their antimicrobial activity and adsorption performance towards Congo red (CR) dye uptake. The presence of bioactive compounds belonging to aromatic compounds, fatty acid esters, heterocyclic compounds, triterpenoids, and sterols serving as reducing and stabilizing agents during nanoparticle formation were confirmed via Gas Chromatography Mass Spectroscopy (GC-MS) analysis. Structural elucidation with UV–Vis, FT-IR, XRD, and TEM confirmed the production of crystalline, quasi-spherical CuO nanoparticles with nanoscale dimensions. The antibacterial activity of CuO BSNPs demonstrated strong performance against Enterobacter spp. and E. coli suggesting that these nanoparticles may be useful against enteric Gram-negative pathogens, while their activity against Campylobacter spp. and S. aureus revealed a broader antimicrobial spectrum. The pseudo-first-order model best described the adsorption kinetics data inferring the predominance of physisorption, while Langmuir model displayed better fitting, signifying monolayer adsorption with a maximum capacity of 40.21 mg g⁻¹. The spontaneity and endothermic natures of the experiment was revealed from the negative values of free energy change (− 1.22 to − 2.45 kJ mol⁻¹) and positive value of enthalpy change (+ 19.78 kJ mol⁻¹). Desorption studies confirmed the reusability of the prepared CuO BSNPs with little efficiency loss over five cycles. The results showcase the potential of CuO BSNPs as sustainable and cost-effective materials in antimicrobial and wastewater treatment applications.