# In Vivo Biosynthesis of Au and Ag NPs Using Two _Medicago sativa_ L. Genotypes
## 3 Results
### Visualisation of Medicago sativa L. Seedlings with Confocal Microscopy  
The alfalfa leaves and roots were visualised in both genotypes using a confocal laser scanning microscope after 24 and 48 h of exposure to the precursor. Control and experimental samples with the highest precursor concentrations (_'Kometa'_ leaves and roots of control, HAuCl4 200 mg/L, AgNO3 1000 mg/L and _'la Bella'_ leaves and roots of control, HAuCl4 200 mg/L, AgNO3 1000 mg/L) were visualised. Light fluorescence was determined for all the mentioned samples, and all samples were imaged. Some of the images are shown in these results. The peak of light fluorescence in all samples was shown when the samples received light with wavelengths from 530 to 550 nm. The wavelength period of peak light fluorescence intensity in leaf and root cells of _'Kometa'_ and _'la Bella'_ after exposure to precursors is shown in Table 7.  
The confocal microscopy results showed that leaves of the _'Kometa'_ genotype from a control sample had some stoma and fragments of a chloroplast. The study used a thick leaf; thus, the leaf tissues and cells overlapped with each other. The maximum fluorescence intensity in _'Kometa'_ leaves for the control sample was about 350 nm, but for the root sample, the fluorescence peak was much higher, exceeding 900 nm. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Genotype** & **Part of the Plant** & **Precursor** & **Precursor Concentration (mg/L)** & **Time of Precursor Exposure (H)** & **Wavelength Range with the Highest Fluorescence Intensity (nm)** \\ \hline \multirow{4}{*}{_'Kometa’_} & Leaf & \multirow{4}{*}{Control} & \multirow{4}{*}{200} & 300–350 \\ \cline{2-3}  & Root & & & & 800–900 \\ \cline{2-3}  & Leaf & & & 1600–1150 \\ \cline{2-3}  & Root & & & 4000–3500 \\ \cline{2-3}  & Leaf & & & 3250–2750 \\ \cline{2-3}  & Root & & & 3750–3500 \\ \cline{2-3}  & Leaf & & & 850–900 \\ \cline{2-3}  & Root & & & 550–650 \\ \hline \multirow{4}{*}{_’Kometa’_} & Leaf & \multirow{4}{*}{HAuCl4} & \multirow{4}{*}{200} & 3750–4000 \\ \cline{2-3}  & Root & & & 4000–3500 \\ \cline{2-3}  & Leaf & & & 3750–3500 \\ \cline{2-3}  & Root & & & 4000–3750 \\ \hline \multirow{4}{*}{_’Kometa’_} & Leaf & \multirow{4}{*}{Control} & \multirow{4}{*}{200} & 1350–900 \\ \cline{2-3}  & Root & & & 3000–2250 \\ \cline{2-3}  & Leaf & & & 600–650 \\ \cline{2-3}  & Root & & & 2600–2000 \\ \cline{2-3}  & Leaf & & & 2000–1400 \\ \cline{2-3}  & Root & & & 3500–3250 \\ \hline \multirow{4}{*}{_’la Bella’_} & Leaf & \multirow{4}{*}{Control} & \multirow{4}{*}{48} & 2250–2000 \\ \cline{2-3}  & Root & & & 600–400 \\ \cline{2-3}  & Leaf & & 400–600 \\ \cline{1-1} \cline{2-3}  & Root & & & 2600–2200 \\ \cline{1-1} \cline{2-3}  & Leaf & AgNO3 & & 2600–2200 \\ \cline{1-1} \cline{2-3}  & Root & & & 1800–1600 \\ \cline{1-1} \cline{2-3}  & Root & & & 3000–2600 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: The wavelength period of peak light fluorescence intensity in leaf and root cells of ‘_‘Kometa’_ and ‘_’la Bella’_ after exposure to precursors. An image of a '_Kometa_' genotype root after 24 h of exposure to 200 mg/L HAuCl4 is shown in Figure 5a. Au particles were seen between the cells of the vascular tissue, which gave off bright fluorescence. The size of these particles could not be determined because they stuck together in many places and formed agglomerates, and some of the particles stuck around the root from the outside and could be seen in the image as larger spots. The maximum fluorescence intensity of these samples for both the leaves and roots increased significantly; thus, HAuCl4 entered the plant roots. After 24 h of exposure to 1000 mg/L AgNO3, the leaves of the '_Kometa_' genotype showed an increase in fluorescence intensity compared to the control, but no Ag particles were visible in either leaves or roots. Figure 5: Image of root sample with 200 mg/L HAuCl4 from the ‘_Kometa_’ genotype (**a**). Image of root sample with HAuCl4 200 mg/L, from the ‘_la Bella_’ genotype (**b**).