Investigating the optical, structural, and therapeutic properties of CuO nanoparticles coated with [BMIM][BF4] Ionic liquid

Abstract

This work reports a chemical synthesis of 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid ([BMIM][BF4] IL) coated copper oxide nanoparticles (CuO-[BMIM][BF4] NPs) by using co-precipitation method. Additionally, bare copper oxide nanoparticles (CuO NPs) are prepared without the addition of the ionic liquid for comparison. Structural morphology and optical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) with selected area electron diffraction (SAED), Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV–Vis), and photoluminescence spectroscopy (PL). XRD analysis revealed the monoclinic phase of synthesised CuO NPs (with and without addition of IL) with an average crystallite size of 15.3 nm and 8.42 nm for CuO NPs and CuO-[BMIM][BF4] NPs respectively. An examination of the UV–Vis spectra revealed that the optical bandgap decreases with the addition of IL to CuO NPs. Scanning Electron Microscope (SEM) revealed the flake like morphologies in the range of nanoscale. TEM Microscope showed the conventional needle structure of CuO-[BMIM][BF4] NPs. Synthesised NPs showed antimicrobial effects against Streptococcus aureus and Pseudomonas aeruginosa as well as pathogenic fungi, including Aspergillus flavus and Candida albicans, as investigated using the disc diffusion technique. Pseudomonas aeruginosa (bacterial pathogen), Candida albicans (fungal pathogen) were significantly inhibited than the other two organisms. Additionally, the prepared CuO nanoparticles were evaluated for their anticancer properties on MCF7 human breast cancer cell lines using the MTT assay. The results indicated that the synthesised CuO nanoparticles exhibited effective cytotoxicity against MCF7 cells, with an IC50 value of 33.37 μg/mL. These findings are briefly discussed in this manuscript.