In this work we study the plasmonic properties of Au nanoparticles on fluorine doped-tin-oxide (FTO) correlating these properties to the structural characteristics of the nanoparticles. We use the laser annealing approach to dewet thin Au films deposited on the FTO surface so to form the Au nanoparticles. However, we found, in view of the optimization of the optical properties, that better structural characteristic for the nanoparticles (i. e, larger mean radii and lower size dispersion) are obtained by irradiating the Au films maintaining the sample immersed in glycerol solution instead of the standard set-up with the samples in air. In fact, when thin films are rapidly melted inside a bulk fluid, the ensuing gas pressure gradients can produce huge acceleration forces that can destabilize the film leading to the Rayleigh-Taylor instability as the leading nanostructuring process. The same experiments performed with the samples …