A model for DNA detection by metal-enhanced fluorescence from immobilized silver nanoparticles on solid substrate

作者：Zhang J; Lakowicz JR^*

来源：Journal of Physical Chemistry B, 2006, 110(5): 2387-2392.

DOI：10.1021/jp055370u

N-(2-Mercaptopropionyl)glycine (tiopronin)-coated silver nanoparticles (average diameter of metal core = 5 nm) were prepared by a modified Brust method. Tiopronin ligands were partially displaced by thiolate single-stranded oligonucleotides via ligand exchange. These particles were immobilized onto a solid substrate through hybridization with target oligonucleotides in a layer-by-layer approach. The dye-labeled complementary oligonucleotides were bound to the particle layers through hybridization. Fluorescence intensity was enhanced with a simultaneous increase of plasmon absorbance from accumulated particles. A steady state was shown at the 10th particle layer and then the fluorescence enhancement showed a plateau. This result reveals that increasing the particle layer contributes to fluorescence enhancement. This novel method was used to detect DNA hybridization through both absorbance and emission spectral changes.

• 出版日期2006-2-9