Initially, it was necessary to determine the best concentration of the natural latex for formation of the sols. To this end, the AgNO3 concentration was fixed as 4 mmol L−1, and the volume of the starting latex solution was varied. Table 1 lists the volume of the NRL solution diluted in 300 mL Mili-QTM water and the respective samplenames. Fig. 2(a) depicts the UV–vis spectra obtained for the samples by varying the NRL content. It was possible to observe the characteristic absorption peak of the silver nanoparticles around 435 nm for all the employed NRL volumes. This absorption peak is due to the surface plasmon resonance of the conducting electrons onto the nanoparticles surfaces [33]. The peak intensity is related to the concentration of colloidal silver. It is also possible to note that as the NRL content is increased, the intensity of the absorption plasmonic peak is enhanced.