Calculation of Extinction Coefficient and Molar Concentration of Gold Nanoparticles using UV-Vis Spectroscopy

Calculating the optical extinction cross-section (sigma(ext)), which consists of absorption cross-sections sigma(abs) and scattering cross-sections sigma(sca), can provide valuable information about the geometry of the nanoparticles and the particle size. In this work, the extinction coefficient (sigma) and the molar concentration (c) of gold nanoparticles (AuNPs), which formed at room temperature upon using dimethylamine borane (DMAB) to reduce the polymer of gold(I) 6-thioguanosine hydrogel, have been calculated. The formed AuNPs were characterized by using ultraviolet-visible spectroscopy (UV-Vis) and transmission electron microscopy (TEM) techniques. Absorption spectra can provide valuable information about the size, extinction coefficient, and concentration of nanoparticles.