From the EDS spectra (see Additional file 1: Figure S9), we have confirmed that the nanoparticles are mainly composed of silver (subtracting the Cu, Si, and C contributions from the TEM grid and Selleckchem Nec-1s the detector window). Some amount of oxygen is also displayed in the EDS results (see Additional file 1: Table S3), probably meaning that some trace amount of the extract is still present in the TEM grid. The crystallographic analysis confirms that the nanoparticles are indeed silver crystals.

For instance, in Figures  6 and 7, we show HR-TEM images of two representative nanoparticles, with the corresponding FFT plot. Very interestingly, these results show that the nanoparticle population has a combination of two kinds of crystal symmetries: face MGCD0103 ic50 centered cubic (fcc) and hexagonal (4H). The prevalence

rates of these geometries are 79% (fcc) and 21% (4H). We have computed the interplanar distances from the micrographs and the FFT plots. In the case of the fcc nanoparticles, the interplanar distances are d 1 = 2.316 Å, d 2 = 1.517 Å, and d 3 = 1.159 Å. They are, respectively, associated with the planes (111), (220), and (222) corresponding to the fcc structure of a silver crystal. On the other hand, the interplanar distances for the 4H structure are d 1 = 2.405 Å, d 2 = 2.275 Å, d 3 = 1.407 Å, d 4 = 1.249 Å, and d 5 = 1.149 Å, corresponding to the planes (101), (1-12), (110), (008), and (203) of a hexagonal 4H structure [61]. We have characterized the nanoparticle population for both the fcc and 4H structures, analyzing 100 particles. The results are shown in Figure  8. We observe that the fcc nanoparticles display two size populations: P005091 mouse one with a small average diameter (around 10 nm) and a second one with a larger diameter (around 28 nm). On the other hand, the hexagonal nanoparticles have only one size population and larger diameters (around 38 nm). Note that the results shown in Figure  8 correspond to samples where the reaction time is of 30 days. Figure 6 HR-TEM images of a representative nanoparticl, with fcc structure. HR-TEM image of a silver

nanoparticle, the crystal planes correspond to a fcc structure (A) with its corresponding FFT plot (B). The other figure (C) is an integrated image from the FFT plot. The reaction time was 96 h. Figure 7 HR-TEM images of a representative nanoparticle, Amylase with hexagonal (4H) structure. HR-TEM image of a silver nanoparticle, the crystal planes correspond to a hexagonal (4H) structure (A) with its corresponding FFT plot (B). The other figure (C) is an integrated image from the FFT plot. The reaction time was 96 h. Figure 8 TEM micrograph displaying both fcc and 4H nanoparticles. The population histogram for each crystal structure is also displayed. The statistical analysis has been performed with 100 nanoparticles. The reaction time was 30 days. The observed features in the TEM, UV-Vis,, and visual observation experiments can be summarized and understood as follows.