纳米银对荧光染料曙红的荧光猝灭效应

Quenching effect of silver nanoparticles on the fluorescence of eosine

在较高温度下制备了平均粒径约为100 nm的胶态纳米银,研究了在水溶液条件下其对荧光染料曙红荧光性能的影响。发现不同浓度的纳米银与荧光素溶液作用后可使荧光强度减弱,并且其猝灭效应随纳米银粒子粒径的减小、纳米银浓度的增加而增大。同时发现溶液pH的升高可使该体系荧光猝灭减小。并从分子结构及纳米银表面局域场和无辐射通道等方面对荧光强度变化的原因作了讨论。

Silver nanoparticles with an average grain size of 100 nm were prepared by the reaction of citrate acid with silver nitrate at high temperature. The fluorescent properties of cosine in the presence of silver nanoparticles were studied in water solution. It was found that the fluorescence intensity of eosine was markedly decreased with an increasing concentration of silver nanoparticles, and the small silver nanoparticles were more efficient quenchers due to their larger surface areas. The influence relating to the pH value of the solution was studied as well.