Silver Nanoparticles - Green Synthesis and Misconception

The authors [1] have said, with great conviction that, the exact position of absorption of silver depends on the dielectric constant of the medium without any experimental evidence. However, it is universally known that this absorption band is solely dependent on the surface plasmon vibration of silver nanoparticles and the other compounds present in the solution. It has nothing to do with dielectric constant of the solvent. As the concentration of silver nanoparticles increases, the absorbance also increases (Figure 1) without any change in the max λ [1].