Tuning of photo thermal and linear optical properties of eosin B dye with surfactant-free gold nanoparticles

Exploring the interactions between gold nanoparticles and dye molecules is essentially significant, particularly for sensing, imaging and lasing applications. In this study, the gold nanoparticles were found to be strongly interacting with the eosin B dye molecules resulted in considerable changes in the thermal diffusivity of the dye and quenching of fluorescence. The laser ablation method was used to synthesize surfactant free spherical gold nanoparticles. The formation and optical properties of gold nanoparticles and eosin B dye solutions were analyzed using UV-visible absorption spectroscopy and fluorescence emission spectroscopy. Size and structural inspections were carried using TEM images. Dual beam thermal lens spectroscopy was employed to investigate the thermal diffusivities of the dye-nanoparticle system. The thermal diffusivities of the samples were found to decrease with increase in concentration of gold nanoparticles. We have also observed an enhancement in the thermal lens signal of the eosin B dye with an increase in the concentration of gold nanoparticles in the system.