采用氧化还原法制备了纳米尺寸的银溶胶, 研究了纳米银粒子对核黄素(Riboflavin, Ri)水溶液吸收光谱和荧光光谱的影响。Ri溶液中加入纳米银粒子, 随着纳米银浓度的增大, 吸收强度不断增强, 372 nm处吸收峰红移, 而444 nm处吸收峰蓝移, 同时发生荧光猝灭现象。从无辐射通道增强、纳米银表面局域场减弱及Ri分子第一激发单重态(S1)布居减少、能量转移等方面初步探讨了荧光猝灭的原因。

The silver nanoparticles have been prepared by oxidation and reduction method and their effects on the optical behaviors of riboflavin aqueous solution have been investigated. The absorption intensity of riboflavin was enhanced. After the silver nanoparticles added into the solution, the 372 nm peak was red-shifted and the 444 nm peak was blue-shifted. The fluorescence of riboflavin solution was quenched with the increase of silver nanoparticles concentration. The mechanism of the quenching of riboflavin aqueous solution has been discussed from the enhancement of non-radiative channel,reduction of local field near the surface of silver nano-particles, distribution reduction of riboflavin molecules in the first single excited stated and energy transfer etc.