## 3 Results and Discussion
In this paper, extracts from different fungi were used for the synthesis of stable metal nanoparticles. The original fungal extracts were transparent but the addition of silver nitrate under homogenization for 72 h, turned the extract darker In both positive and negative controls, no color change was observed (Figure 1). A color change during the reaction is attributed to the reduction of Ag\({}^{+}\) ions in Ag\({}^{0}\) and the formation of silver nanoparticles [25]. Moreover, there was a variation in the color of the synthesis reactions according to the extract used in the reduction of silver nitrate, ranging from light yellow (isolated 1258) to dark brown (isolated SE109 and 447). The plasmonic surface resonance (SPR) present in the nanoparticles promotes the color change of their synthesis reactions, being affected by the conformation of the nanoparticle inside the suspension [26]. A darker coloration in the synthesis reaction may indicate the presence of larger or aggregated nanoparticles, which tend to have peaks at a longer wavelength than smaller nanoparticles. The morphology of the nanoparticle also influences the distribution of electrons on the surface of the particle, affecting the color of its suspension. In addition,  
Figure 1: Colors of the synthesis reaction of silver nanoparticles with aqueous extracts of different entomopathogenic fungi. greater color intensity of the synthesis reaction is also related to the presence of a greater number of nanoparticles formed. The UV/visible spectroscopy of the AgNPs showed absorbance peaks around 410-550 nm (Figure 2). According to the literature, peaks in the UV absorption spectrum between 400 and 550 nm are associated with the formation of nanoparticles [27]. The results of UV/visible spectroscopy of the synthesis reactions confirm the formation of nanoparticles by the action of tested entomopathogenic fungi extracts, except for the extract from the SE201 fungus. Figure 2: _Cont._  
Figure 2: UV/visible absorption spectra of the synthesis reactions of silver nanoparticles with aqueous extracts of different entomopathogenic fungi. The used blank solution was the fungal extract solution. Biomolecules (proteins, enzymes, vitamins, toxins, or other secondary metabolites) present in extracts of entomopathogenic fungi are responsible for reducing silver ions and forming AgNPs. The hydroxyl or carboxyl groups in these metabolites react with the metallic salt, promoting electron donation through an oxidation-reduction reaction, resulting in the formation of the nanoparticles. Mean diameter and polydispersity index (PI) were also measured for AgNPs using dynamic light scattering (DLS) (Table 3). AgNPs showed a mean diameter ranging between 40.14 and 289.13 nm. Nanoparticles with a smaller size were synthesized using extracts 447 (40.14 nm), SE109 (61.14 nm), 1213 (69.36 nm), SE103 (77.08 nm), 1260 (77.56 nm), and SE110 (90.29 nm). AgNPs produced with species of entomopathogenic fungi _B. bassiana_, _M. anisopliae_, and _I. fumosorosea_ are described in the literature. _B. bassiana_ showed less than 100 nm [9; 28] and a similar result was obtained for _M. anisopliae_[29] and _I. fumosorosea_[8]. PI varied between 0.165 and 0.627 (Table 3). This parameter assesses the homogeneity of the size of the suspended particles, and PI values up to 0.3 indicate the presence of nanoparticles with a low polydispersity [30]. Thus, among the smallest medium-sized nanoparticles, it was observed that the nanoparticles from the isolates SE110, SE103, 1260, and 1213 showed lower PI values (0.250-0.342), being considered monodisperse. Spherical silver nanoparticles (Figure 3a) attached to the irregular fungal extract structure were observed by SEM, showing sizes between 200 and 600 nm (Figure 3b). These results suggest an irregular shape due to silver nanoparticle adherence. [PERSON]'s correlation coefficients showed the existence of a correlation between the analyzed variables, with differences in significance and proportionality.