Self-assembled plasmonic silver nanoparticle films on anodic alumina for SERS applications

A new approach to making silver colloid nanoparticle based SERS substrates has been demonstrated. A self-assembled silver film with plasmon resonance has been obtained by self-assembly. Four-valent ammonium salts have been used as coordinating molecules. The method is simple and does not involve complicated machinery or difficult mask making techniques that are used to fabricate SERS substrates today. It involves mixing the tetraoctylammonium bromide or tetrabutylammonium nitrate with hexane and silver nanoparticle water colloid solution in one vial, shaking it to obtain a monolayer film on hexane surface and just pouring it onto the cleaned substrate. The anodic alumina barrier layer has been used to induce more uniform self-assembly of colloid films. This SERS structure can be used in conventional plasmonics, sensors and medical applications