[Quenching effect of gold nanoparticles for fluorescein sodium]

The spectroscopic characteristic of interaction of fluorescein sodium and gold nanoparticles with different sizes was investigated via UV-Vis and fluorescence spectrophotometry. It was shown that fluorescein sodium adsorbed respectively onto the different sized gold nanoparticle surface suffers different extent of quenching of their fluorescence. The quenching efficiency is different for different sized gold nanoparticles. It was found that smaller gold nanoparticles are more efficient quenchers due to their larger surface areas. The quenching mechanism was discussed. It was a dynamic quenching.