An overview of the unique absorption and scattering characteristics of gold nanoparticles: experimental and theoretical study

Abstract

Theoretical prediction of the unusual optical properties shown by the gold (Au) nanomaterials remains challenging. Based on this fact, some colloidal Au nanoparticles (AuNPs) were prepared in ethanol and demonized water using the versatile pulse laser ablation in liquid (PLAL) method and characterized. The pulsed laser irradiation energy-dependent optical absorbance and morphology of these AuNPs were determined. Analytical Mie–Gans scattering model was applied to interpret the experimentally observed absorption spectra of these colloidal AuNPs. In addition, the AuNPs size and shape-dependent absorbance were predicted accurately by fitting the recorded spectra with the analytical model simulation. The results revealed that the dielectric function of the AuNPs played a considerable role to realize the best fit of the experimental absorption data. The average sizes of the AuNPs predicted by the proposed analytical model were tallied well with the experimentally measured ones. It is found that an accuracy of more than 8% on the particle size between experimental and predicted data. It is established that the modified Mie–Gans scattering model can provide a better understanding of the distinct absorption attributes of the colloidal AuNPs synthesized by the PLAL method in various liquid media.