Mycogenesis of cerium oxide nanoparticles using Aspergillus niger culture filtrate and their applications for antibacterial and larvicidal activities

Abstract

Abstract: Cerium oxide nanoparticles (CeO2 NPs) were synthesized using Aspergillus niger culture filtrate. The mycosynthesized CeO2 NPs were characterized by UV–Visible (UV–Vis), Fourier Transform Infrared (FT-IR), X-ray diffraction (XRD), Micro Raman, Thermogravimetric/Differential Thermal Analysis (TG/DTA), Photoluminescence, and Transmission Electron Microscopy (TEM) analyses. UV–Vis spectrum exhibited a corresponding absorption peak for CeO2 NPs at 296 nm, and the functional groups present in the fungal filtrate responsible for the synthesis of NPs were analyzed by FT-IR. The further characterization of the mycosynthesized CeO2 NPs revealed particles of the cubic structure and spherical shape, with the particle sizes ranging from 5 to 20 nm. The antibacterial activity of CeO2 NPs was examined in respect of two Gram-positive (G+) bacteria (Streptococcus pneumoniae, Bacillus subtilis) and two Gram-negative (G−) bacteria (Proteus vulgaris,Escherichia coli) by disk diffusion method. The test results for CeO2 NPs at a concentration of 10 mg/mL showed higher activities on the zone of inhibition of up to 10.67 ± 0.33 and 10.33 ± 0.33 mm against Streptococcus pneumonia and Bacillus subtilis, respectively, The CeO2 NPs caused 100 % mortality on first instar of Aedes aegypti at 0.250 mg/L concentration after 24-h exposure. The mycosynthesis of CeO2 NPs is a simple, cost-effective and eco-friendly approach and it will also potentially helpful to control pathogenic bacteria and dengue vector. Graphical Abstract: [Figure not available: see fulltext.]