Phytonanofabrication of Copper Oxide from Albizia saman and Its Potential as an Antimicrobial Agent and Remediation of Congo Red Dye from Wastewater

Abstract

Metal nanoparticle fabrication through plant-based green methods is considered the gold standard among the various synthesis techniques owing to its simplicity, eco-friendliness, ease of use, and the huge diversity of plant species. Copper nanoparticles (CuONPs) have proven their potential in the fields of medicine, agriculture, pharmaceutics, and catalysis, and are being synthesized using various physicochemical and biological methods. Here, the authors have reported on the first-ever use of Albizia saman leaf extract for the development of CuONPs. Phytochemical analysis of the methanolic extracts of the plant exhibited the presence of phenols (32.31%), tannins (12.27%), and flavonoids (16.72%). The phytonutrients existing in leaf extract successfully reduced the copper salt in the CuONPs. A detailed investigation of the synthesized CuONPs was performed using advanced instruments. The UV-Vis spectra exhibited an absorbance peak at 290 nm, while the X-ray diffraction pattern (XRD) revealed that the average crystallite size was about 29.86 nm. Dynamic light scattering (DLS) revealed that the average hydrodynamic size of the CuONPs was 72.3 nm in diameter, while its zeta potential was −0.49, with a negative polarity. Fourier transform infrared spectroscopy showed the major bands in the region of 400 to 1000 cm−1, suggesting the formation of CuONPs, while the band in the region of 1100 to 2600 cm−1 shows the association of plant molecules with the phytonanofabricated CuO particles. Transmission and scanning electron microscopy showed the spherical shape of the CuONPs, whose size was about 20–50 nm. The phytonanofabricated CuO exhibited antibacterial activity by forming a zone of inhibition (ZOI) against Escherichia coli, Staphylococcus aureus, and Candida albicans. The removal efficiency of the CuONPs was 33.33% for Congo Red dye. The removal efficiency of the phytonanofabricated CuO for CR dye was reduced to 16% after the 4th cycle.