QUATSOME-ENCAPSULATED SILVER NANOPARTICLES AS SERS SUBSTRATES FOR PYRENE AND PRODAN

Plasmonics has important applications in various fields including surface-enhanced Raman scattering (SERS), surface-enhanced fluorescence (SEF), plasmonic photothermal therapy (PPT). One of the disadvantages of the metal nanoparticles is the low stability during time and the potential cytotoxicity to cells and tissues. One of the approach to avoid these issues is to encapsulate the plasmonic nanoparticles with lipid membranes. In this work we have used quatsomes to encapsulate silver nanoparticles to be used as SERS substrates. Quatsomes are bilayer nanovesicles made of sterols and quaternary ammonium surfactants that have shown to be stable for years. Results from dynamic light scattering (DLS) and UV-vis absorption indicate that the coated silver nanoparticles are also stable at least for two months. To test the applicability of quatsome-modified silver nanoparticles as SERS substrates, the intensity enhancement capabilities for two well known fluorescent probes, pyrene and prodan, was examined. Data show that these molecules are inserted in the quatsome layer and are placed near the nanoparticle surface resulting in an efficient SERS intensity increase in comparison with the normal Raman spectra. In conclusion, this study demonstrates that the developed quatsome-encapsulated silver nanoparticles have excellent plasmonic-enhanced capabilities and long term stability. The results of this work will be presented and discussed here with focus in future application in drug delivery, bio-imaging and medical uses.