# Alginate Silver Nanoparticles and Their Effect on Sperm Parameters of the Domestic Rabbit
## 3 Results and Discussion
### Spectroscopic Analysis (UV-Vis and ATR-FTIR)  
Figure 2 displays the UV-Vis spectra of composites containing silver nanoparticles and a control sample. Characteristic absorption bands were observed for silver nanoparticles at 430 nm for the sample with xylose-reduced AgNPs and at 417 and 510 nm for the composite with sodium borohydride-reduced AgNPs. The band above 510 nm is created by the coupling of surface plasmons to the aggregated particles. Several studies [53; 54; 59; 60; 61; 62] have demonstrated the effectiveness of UV-Vis spectroscopy in detecting the presence of metallic nanoparticles. Furthermore, these studies demonstrate that the size, shape, and distribution of particles significantly affect the shape and position of the absorption band in the UV-Vis spectra. Therefore, it is crucial to consider these factors when analyzing the spectra [54]. Typically, an increase in nanoparticle size results in a shift of the absorption band towards longer wavelengths, while an increase in polydispersity is indicated by a broadening of the band. These findings partially align with our previous studies [53; 54]. For silver nanoparticles obtained through the reduction reaction with sodium borohydride, there was a significant increase in polydispersity, nanoparticle size, and aggregation. These results were also confirmed by electron microscopy. The ATR-FTIR spectra for the samples in Figure 3 were analyzed in the spectral range of 700-4000 cm\({}^{-1}\). The vibrations ranging from 3500-3000 cm\({}^{-1}\) are related to the hydroxyl  
Figure 2: UV–Vis spectra of the control sample (Alg—black line) and the samples containing AgNPs (AgNP AlgB—red line and AgNP AlgX—blue line). groups present in the polymer and glycerol. A set of overlapping bands with moderate intensity appear around 2941 and 2879 cm\({}^{-1}\), signifying the stretching vibrations of CH and CH\({}_{2}\) groups in the alginate and glycerol structures. The bands observed at 1600 and 1399 cm\({}^{-1}\) were attributed to the asymmetric and symmetric stretching vibrations of the carboxylate salt ion, respectively. A number of vibrations in the range 1100-1000 cm\({}^{-1}\) assigned to the glycoside bonds in the polysaccharide (C-O-C stretching). The obtained results are consistent with the data found in the literature [63; 64; 65]. No significant changes were observed in the spectrum of the composites compared to that of sodium alginate, which may be due to the very low concentration of metallic nanoparticles. Further studies identified the possibility of modifying the activity of nanoparticles by enriching them with additional substances. The results of the research work of the team of [PERSON] et al. [65] made it possible to obtain polymer composites, also based on sodium alginate, with silver and gold nanoparticles additionally enriched by the presence of graphene oxide. Similar to the present work, the evaluation of the physicochemical properties of these composites through the use of methods such as UV-VIS spectroscopy, SEM electron microscopy and the evaluation of Fourier transform infrared spectra allowed us to confirm the occurrence of the reduction reaction of nanoparticles from the salt containing the respective metals gold and silver. Obtaining spherical particles with sizes close to 20 nm is in dialogue with the biometric values of the silver structures presented in this manuscript. A strong antibacterial effect, inhibiting the growth of 11 bacterial strains, was demonstrated by silver nanoparticles enriched with graphene oxide compared to gold nanoparticles with graphene oxide, which did not show the ability to limit microbial growth [65]. Modern biopolymer technology also makes it possible to obtain innovative composites containing such active substances as quantum dots.