Mr Felix Benz

Few Molecule Vibrational Spectroscopy in Plasmonics

Gold nanoparticle assembled into nanoarchitectures can be used to investigate single molecules using surface enhanced Raman spectroscopy (SERS). This high sensitivity arises from the fact that incoming light can couple to collective electron vibrations in the gold nanoparticles creating fields which are tightly confined at the particle surface. By using two or more adjacent nanoparticles these states couple together to form highly localised states on the 1 nm scale, in the so-called hotspots. The Raman signal of molecules in such a hotspot is extremely amplified by over billion-fold allowing the detection of single molecules. However, the signal strongly depends on the geometry of the nano-architecture. Assembling structures with a reliable geometry and nanometre-precise control over the gap between the nanoparticle remains a major challenge.

For my research I am using molecular systems, like self-assembled monolayers or hybrid lipid bilayers assembled inside individual gold nanostructures. I am investigating the influence of a molecular conductivity on the plasmon resonances as well as the dynamic behaviour of these molecular systems by SERS in real time.