Fabrication of oblique angle deposited Ag nanorods for enhanced fluorescence substrate

Fluorescence is a widely used tool in biology for imaging and sensing biomaterials. Metal-enhanced fluorescence is a powerful technology for improving sensitivity of fluorescence analysis, where the interactions of fluorophores with metallic nanoparticles results in fluorescence enhancement. In this study, we proposed an inexpensive large area fabrication method of Ag nanostructures for enhanced fluorescence substrate using oblique angle deposition. To examine the feasibility of the proposed substrate and maximize the signal enhancement effects, the oblique angle deposited Ag nanorods substrates with different nanorod lengths were prepared and the measured fluorescence signals from the Streptavidin conjugate Cy5 on the Ag nanorods substrates were compared with those on a glass substrate. The enhancement factor is increased by increasing the length of Ag nanorods, because of the higher surface Plasmon resonance effect of high aspect ratio structure. The maximum enhancement factor of ~23 was obtained from the Ag nanorods substrate with a nanorod length of 1000 nm.