DNA Photonics
(Nelli Bossert & Dirk Bouwmeester)

Cell and Ag-DNA Exploring fluorescent Ag-DNA in living cells:
Fluorescent Ag-DNA nanomaterials enter living cells and show potential for transport and biosensing applications.

We investigate biological processes inside living cells utilizing the unique optical and chemical properties of DNA encapsulated fluorescent silver clusters (Ag-DNA). The recently discovered silver cluster emitters are composed of only 5-20 atoms. These nanoscale emitters simply self-assemble onto DNA host materials. This assembly results in a DNA sequence-dependent shape and size for each emitter, as well as specific absorption and emission spectra (with a range of 500-850 nm).

 

These properties make Ag-DNA very promising for in vitro and in vivo studies. Moreover, the binding of the silver to host DNA can be made deliberately weak, leading to the release of silver ions. Those silver ions can then interfere with the natural DNA processes and induce apoptosis. Preliminary results show that Dictyostelium discoideum cells readily take up several Ag-DNA structures. These structures localize to the nucleus and show a shift in emission frequency inside the cell, allowing them to potentially be used as sensors to the intra-cellular environment.

 

This research is a joint project between Prof. Doris Heinrich (Biophysics) and Prof. Dirk Bouwmeester (Quantum Optics), and is performed in close collaboration with Maria Götz Msc (Fraunhofer Attract Group, Würzburg, Germany)