Malicka Joanna, Gryczynski Ignacy, Fang Jiyu, Lakowicz Joseph R
Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA.
Anal Biochem. 2003 Jun 15;317(2):136-46. doi: 10.1016/s0003-2697(03)00005-8.
We examined the fluorescence spectral properties of DNA oligomers, labeled with Cy3 or Cy5, when bound to quartz surfaces coated with metallic silver particles. Prior to binding of labeled DNA the surfaces were treated with polylysine or 3-aminopropyl triethoxysilane or were coated with avidin for binding of biotinylated oligomers. The fluorescence intensities were increased an average of 8-fold on these surfaces. Despite the increased emission intensity, the photostability of the labeled DNA was the same or higher on the silver-coated surfaces than on the uncoated slides. The time-integrated intensities, that is the area under the intensity plots with continuous illumination, increased an average of 6-fold. In all cases the lifetimes were dramatically shortened on the silver particles, indicating an over 100-fold increase in the radiative decay rates. These results suggest the use of substrates containing silver particles for increased sensitivity of DNA detection on DNA arrays.
我们研究了用Cy3或Cy5标记的DNA寡聚物与涂有金属银颗粒的石英表面结合时的荧光光谱特性。在标记的DNA结合之前,表面用聚赖氨酸或3-氨丙基三乙氧基硅烷处理,或者用抗生物素蛋白包被以结合生物素化的寡聚物。在这些表面上,荧光强度平均增加了8倍。尽管发射强度增加,但标记的DNA在涂银表面的光稳定性与未涂覆的载玻片相同或更高。时间积分强度,即连续光照下强度图下方的面积,平均增加了6倍。在所有情况下,银颗粒上的寿命都显著缩短,表明辐射衰变率增加了100倍以上。这些结果表明,使用含有银颗粒的底物可提高DNA阵列上DNA检测的灵敏度。