Metal enhanced fluorescence using nanostructures on silver formed with Ti:Saphire femtosecond pulsed laser

Metal enhanced fluorescence is a phenomenon that occurs when a fluorophore is positioned near a conductive structure. Structures can be formed by the interaction of high-energy laser with a sample, on which the femtosecond laser pulses interact with the surface without heat effects. This work aims to study nanostructure formation in polished bulk silver, in order to amplify signals of fluorescence. A Titanium-sapphire femtosecond laser was used to mark silver surfaces. SEM images shows nanostructures formed in chaotic agglomerate of nanospheres with size of 50-800nm. Using Protoporphyrin-IX, the fluorescence amplification was around 300 times compared to a surface without the nanostructures.