Nio nps

Engineered NiO-NP was procured from Sigma Aldrich, (St. Louis, USA) [Product code 637130, molecular weight: 74.69, EC Number: 215-215-7, Pubchem Substance ID 24882831, <50 nm particle size Transmission Electron Microscopy (TEM), 99.8% trace metal basis]. The nanoparticle was directly suspended in deionized, ultrapure water (DI-water), and dispersed by ultrasonic vibration (60 W, 40 kHz) for 45 min to produce seven different concentrations as follows: 10, 25, 50, 62.5, 125, 250, and 500 mg L⁻¹.
NiO-NPs were characterized by TEM, Dynamic Light Scattering (DLS), and Zeta (ζ) Potential Measurements. Estimation of morphology and size of NiO-NPs was based on the observations from TEM, performed on a Field Emission Transmission Electron Microscope (JEM-2100F, JEOL, Japan) at 200 keV. DLS was performed on a ZetaSizer-HT (Malvern, UK) to determine the hydrodynamic sizes of the NiO-NPs in suspension. The zeta potential values of NiO-NPs, dispensed in ultrapure water, were determined by Zetasizer 2000 (Malvern Instruments Ltd., UK) as the average of 10 readings and compared to previous reports (Lim et al., 2013 (link)). Polydispersity index was calculated as:
$\begin{array}{l}PDI={(\sigma /\text{d})}^2\end{array}$
where σ is standard deviation and d is mean diameter, according to Ates et al. (2016 (link)).

NiO NPs were purchased from Nanostructured and Amorphous-Materials (Houston, TX, USA) and used in our experiments. The physicochemical analysis of NiO NPs followed previously described methods [11 (link)]. The surface area of NiO NPs was measured using a Micromeritics Tristar 3000 analyzer (Micromertitics Ltd., Bedfordshire, UK) from ParticleCIC Ltd. (Leeds, UK). The average size of NiO NPs was determined using transmission electron microscopy (TEM; JEM-1200EXII, JEOL, Tokyo, Japan) and more than 100 individual particle sizes were analyzed using the software. Endotoxin measurements were evaluated using an endpoint chromogenic Limulus amoebocyte lysate assay kit (Cambrex, Walkersville, MD, USA).