Bio-inspired Senna auriculata flower extract assisted biogenic synthesis, characterization of cobalt oxide nanoparticles and their antibacterial and antifungal efficacy

Abstract

Senna auriculata flower extract was utilized in this study for the bio generation of cobalt oxide (Co3O4) nanoparticles. Powder X-ray diffraction (XRD), Fourier Transformed Infrared spectra (FTIR), UV–Visible spectroscopic analysis, and field-emission scanning electron microscopy (FESEM) were used to analyze the resulting Co3O4 nanoparticles. These nanoparticles having a crystallite size of 31.94 nm were highly crystalline and had a cubic spinal structure, as indicated by the high-intensity peaks of the XRD spectra. The Co3O4 nanoparticle's remarkable dispersion and spherical shape are highlighted in the FESEM image. Additionally, these biosynthesized Co3O4 nanoparticles have shown efficient antibacterial efficacy against gram (+) and gram (−) bacteria, including Staphylococcus aureus, Streptococcus mutans, Klebsilla pneumonia, and E. coli, along with antifungal efficacy against Aspergillus flavus and Aspergillus Niger under in-vitro environmental conditions. The observed zone of inhibition values against all bacteria and fungi ranged from 22 ± 0.61 mm to 26 ± 0.81 mm and 20 ± 0.42 mm to 33 ± 0.67 mm, respectively. The Senna auriculata flower extract-assisted Co3O4 nanoparticles showed minimum inhibitory concentration values that ranged from 8 to 20 μg/ml against isolated bacteria. This result shows that the Co3O4 nanoparticles exhibited high antibacterial and anti-fungal behaviour with significant differences between other synthesize procedures and the control (Positive control).