Surface enhanced Raman scattering and fluorescence of tagged phospholipids in Langmuir-Blodgett monolayers

The surface-enhanced Raman scattering (SERS) and surface-enhanced resonance Raman scattering (SERRS) phenomena can be observed when molecules are close to metallic nanoparticles that sustain localized surface plasmon resonances (LSPR). There is a broad spectrum of metallic nanostructures (mainly silver and gold) that may be used to improve the efficiency of Raman signals. Here, we used silver island films (SIFs) to enhance the scattering from tagged phospholipids coating the SIFs, and fabricated using Langmuir-Blodgett (LB) technique. Single molecule detection (SMD) can be approached using LB-SERRS technique and using mixed LB monolayer, containing about one target molecule per 1 &mgr;m.;2ofsurface area. Fluorescence enhancement is achieved with shell-isolated nanoparticles (SHINs) synthesized and delivered to the LB substrate, a technique we term SHINEF. Simply, a drop of SHINs is delivered to quartz slide covered by LB of tag-phospholipid to produce surface-enhanced florescence.