Cerium Oxide Nanoparticles and Their Efficient Antibacterial Application In Vitro against Gram-Positive and Gram-Negative Pathogens

Abstract

In this study, the antibacterial activity of cerium oxide nanoparticles on two Gram-negative and three Gram-positive foodborne pathogens was investigated. CeO2 nanoparticles (CeO2 nps) were synthesized by a Wet Chemical Synthesis route, using the precipitation method and the Simultaneous Addition of reactants (WCS–SimAdd). The as-obtained precursor powders were investigated by thermal analysis (TG–DTA), to study their decomposition process and to understand the CeO2 nps formation. The composition, structure, and morphology of the thermally treated sample were investigated by FTIR, Raman spectroscopy, X-ray diffraction, TEM, and DLS. The cubic structure and average particle size ranging between 5 and 15 nm were evidenced. Optical absorption measurements (UV–Vis) reveal that the band gap of CeO2 is 2.61 eV, which is smaller than the band gap of bulk ceria. The antioxidant effect of CeO2 nps was determined, and the antibacterial test was carried out both in liquid and on solid growth media against five pathogenic microorganisms, namely Escherichia coli, Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus. Cerium oxide nanoparticles showed growth inhibition toward all five pathogens tested with notable results. This paper highlights the perspectives for the synthesis of CeO2 nps with controlled structural and morphological characteristics and enhanced antibacterial properties, using a versatile and low-cost chemical solution method.

Green synthesis of cerium oxide nanoparticles using Acorus calamus extract and their antibiofilm activity against bacterial pathogens

“…The average crystalline size of CeO 2 -NPs was found to be 22.03 nm using the Scherrer formula. A similar XRD pattern was also recorded for chemically synthesized cerium oxide nanoparticles with an average crystalline size of 7 nm (Pop et al, 2020). Cerium oxide nanoparticle synthesized using honey have been reported previously that were spherical in shape and its size was about 23 nm (Darroudi et al, 2014).…”

“…There were also some low-intensity peaks at 59.01 , 69.27 , 76.62 , and 78.86 that belonged to (222), (400), (331), and (420) planes, respectively(Bandyopadhyay, Peralta-Videa, Plascencia-Villa, José-Yacamán, & Gardea-Torresdey, 2012;Corral-Diaz et al, 2014). The average crystalline size CeO 2 -NPs as was calculated using Debye Scherer's equation-1(Pop et al, 2020):…”

Biofabrication of Gold Nanoparticles Using Capsicum annuum Extract and Its Antiquorum Sensing and Antibiofilm Activity against Bacterial Pathogens

“…The XRD pattern of AuNPs-CA exhibited four intense peaks at 2θ values 38.183, 43.990, 64.550, and 77.670°, which correspond to Bragg’s reflections of gold nanocrystals. 28 The Debye–Scherrer equation ( eq 1 ) was used to calculate the average crystalline size of AuNPs-CA 29 where D p is the average crystalline size, λ is the wavelength of Cu Kα (1.54060 Å), θ is the Bragg angle, and β is the full width at half-maximum (FWHM). The average crystalline size of the AuNPs-CA calculated using the Debye–Scherrer formula was found to be 20.80 nm.…”

Regulation of Ce (Ⅲ) / Ce (Ⅳ) ratio of cerium oxide for antibacterial application

“…In general, gram-positive bacteria are composed of thicker, waxy cell wall, making them more resistant to the CeO 2 nanoparticles than gram-negative bacteria. For example, the gram-positive Bacillus cereus has a cell wall of 55.4 nm, while the gram-negative S. typhimurium has a cell wall of only 2.4 nm ( Kalantari et al., 2020 ; Pop et al., 2020 ). However, in this study, bacteria are living well on CeO 2 , meaning that the electrostatic attraction between CeO 2 and bacteria is not the main antibacterial factor.…”