Berlin 2018 – wissenschaftliches Programm
CPP 20.48: Poster
Montag, 12. März 2018, 17:30–19:30, Poster A
Silica Coating for Stabilization of Tubular J-aggregates — •Katherine Herman, Stefan Kirstein, and Jürgen P. Rabe — Humboldt Universität zu Berlin Institut für Physik, Berlin, Germany
Cyanine dyes are remarkable for their ability to form supramolecular aggregates with both diverse morphologies as well as the signature narrow absorbance and emission bands of J- or H- aggregates. Cyanine dyes that form one dimensional nanostructures are of particular interest not only for their potential as light harvesting and energy transport structures, but also as systems for fundamental linear and non-linear spectroscopic studies. However, several powerful methods for investigating optical and energy transfer properties require that the sample be stable under dry and low pressure conditions. A possible means of stabilization is inorganic coating of the water soluble aggregates. Here we present an approach for a silica coating to stabilize tubular aggregate of amphiphilic cyanine dyes for dry and low pressure investigations. An initial monolayer of silica is formed by ionic self assembly of a functionalized organosilane on the aggregate surface. Further shell growth is achieved by gradual addition of a second organosilane under basic conditions. Evidence for silica shell growth on the aggregate comes from fluorescence spectroscopy and atomic force microscopy.