G/transmission ogy and good dispersion of them. Figure 3a shows the bright-field scanning/transmission electron microscopy (BF-STEM) image of the green synthesized AuNPs. As might be obelectron microscopy (BF-STEM) image of the green synthesized AuNPs. As can be 20(S)-Hydroxycholesterol Formula observed within the image, the AuNPs had a quasi-spherical shape with an typical particle size served in the image, the AuNPs had a quasi-spherical shape with an average particle size of 23.96 0.47 nm (Figure 3e). Homogeneous particle size Pinacidil Autophagy distribution with no aggregates or agglomeration were observable, indicating accomplishment in controlling the AuNPs size by way of green synthesis working with Sargassum spp. extracts. Figure 3b shows the annular dark-field (ADF)-STEM image, in which the AuNPs seem to brightly contrast because of incoher-Intensity (a. u.)Toxics 2021, 9,six ofToxics 2021, 9, x FOR PEER REVIEWof 23.96 0.47 nm (Figure 3e). Homogeneous particle size distribution with no aggregates or agglomeration were observable, indicating results in controlling the AuNPs size via green synthesis employing Sargassum spp. extracts. Figure 3b shows the annular dark-field (ADF)-STEM image, in which the AuNPs appear to brightly contrast because of incoherent scattering. It is important to mention that within the ADF-STEM (also known as Z contrast) image, the AuNPs possess a higher atomic quantity than that on the C from organic compounds and assistance, and they may be shown as bright dots. To visualize the contrasting in the organic compounds in the Sargassum spp., the BF-STEM image was colored to highlight subtle variations in intensity, which may possibly be tough to discern in a grayscale image. Figure 3c shows the color look-up table (CLUT), exactly where it may be seen clearly that the AuNPs are covered by an organic compound, which aids prevent agglomeration and aggregation. The aggregation or agglomeration of nanoparticles reduces the prospective of catalytic properties as a result of restriction in the interfacial region. Figure 3d shows the EDS evaluation on the AuNPs in which the elemental composition on the sample is appreciated. The presence of gold confirms the composition of the nanoparticles, as the only metallic phase. The signals from the other components (Cu, Al, and Sn) come from the sample holder used. Elements in the metallic salt and extract for example Cl, K, and As usually are not present inside the spectrum, indicating that the cleaning process of the AuNPs is effective and also the obtained outcomes will be the item 7 of 18 in the interaction with the nanoparticles with all the dyes.a)b)c)d)Intensity (a.u.)CuAu Al C O SnOrganic Compounde)Frequency 30 20 10Energy (eV)23.96 0.47 nmParticle size (nm)Figure STEM micrographs of AuNPs synthesized making use of Sargassum spp., (a) BF-STEM image, (b) Figure three.3. STEM micrographs of AuNPs synthesized using Sargassum spp., (a) BF-STEM image, ADF-STEM image, (c) CLUT image, (d) EDS evaluation, and (e) the and (e) the correspondingpar(b) ADF-STEM image, (c) CLUT image, (d) EDS evaluation, corresponding histogram of histogram of ticle size distribution. particle size distribution.The DLS technique was utilised to identify the particle size and size distribution profile on the AuNPs. Figure 4a shows the DLS histogram of the AuNPs. As could be observed, the average particle size was 22.27 nm, having a normal deviation of three.4 nm. The polydispersity index (PDI) indicates the breadth of your size distribution, exactly where a worth of ten or significantly less implies that the sample is monodisperse. Here, the PDI calculated was 2.32 , indicating a monodisperse si.