摘要
Fluorescence enhancement in a DNA-dye system is favorable for sensitive and accurate DNA detection/ sensing technologies.In this paper,we report that the fluorescence of the double-stranded DNA(dsDNA) and SYBR GreenⅠ(SG) system(dsDNA-SG) can be effectively enhanced by negatively charged magnetic iron oxide (Fe_2O_3@DMSA) and gold nanoparticles in suitable concentrations,but positively charged nanoparticles quench the fluorescence.Effects of the Fe_2O_3@DMSA on the fluorescence intensities are investigated with dsDNA-SG of different lengths or complexities.The results show that nanoparticles perform similarly in enhancing fluorescence intensity for several kinds of dsDNA.However,the dsDNA concentration determines the fluorescence amplitude.It shows that fluorescence intensity of lower concentration dsDNA is enhanced remarkably in DNA-SG.The finding may be useful in sensitive biomolecular detection.
Fluorescence enhancement in a DNA-dye system is favorable for sensitive and accurate DNA detection/ sensing technologies. In this paper, we report that the fluorescence of the double-stranded DNA （dsDNA） and SYBR Green I （SG） system （dsDNA-SG） can be effectively enhanced by negatively charged magnetic iron oxide （Fe203@DMSA） and gold nanoparticles in suitable concentrations, but positively charged nanoparticles quench the fluorescence. Effects of the Fe203@DMSA on the fluorescence intensities are investigated with dsDNA-SG of different lengths or complexities. The results show that nanoparticles perform similarly in enhancing fluorescence intensity for several kinds of dsDNA. However, the dsDNA concentration determines the fluorescence amplitude. It shows that fluorescence intensity of lower concentration dsDNA is enhanced remarkably in DNA-SG. The finding may be useful in sensitive biomolecular detection.
基金
supported by grants from the National Science Foundation of China (No.10975175,90923002)
the Chinese Academy of Sciences(No.KJCX2-EW-N03)
