Taylor made multi-component nanocrystals with plasmon-exciton interactions for fluorescence enhancement and sensing

• Applicant: Privatdozent Dr. Dirk Dorfs
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: from 2012 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 226604426

The project aims at developing new synthetic pathways towards inorganic nanocrystals of tailored size, shape and complex compositions with a specific focus on systems exhibiting plasmon-exciton interactions such as fluorescence enhancement. The combination of seed mediated growth approaches together with metal tip growth, cation exchange techniques and cast mold approaches is expected to yield previously inaccessible nanocrystalline materials. Cation exchange reactions will allow to easily transform complicated shaped nanocrystals into other materials without changing their shape. „Cast mold“ approaches can produce more unconventional shapes, like e.g. hollow or concave particles. Here the synthesis route is to start with e.g. metal nanoparticles, onto which an oxide or a semiconductor compartment is grown, and to selectively dissolve the metal in a second step. Furthermore, plasmonic metal tips will be grown selectively onto these nanocrystals. Once the synthetic techniques are sufficiently developed, tailor made multicomponent inorganic nanocrystals with a specific focus on systems exhibiting tunable plasmon-exciton interactions will be synthesized. Apart from opening new insights into plasmon-exciton interactions in nanocrystals, these systems will be designed to show plasmon induced tunable strong fluorescence enhancement effects. The project will also be expanded towards fluorescence enhancement in the near infrared spectral range opening a broad field of potential applications. The gained knowledge should be applicable e.g. in next generation solar cells, LEDs and biomedical imaging. Furthermore, nanocrystals with partially concave compartments (synthesized via above mentioned „cast mold“ approaches) will be exploited for selective sensing of other nanoparticles using key-lock recognition mechanisms with resulting plasmon-exciton interactions and hence key-lock recognition induced fluorescence enhancement. These advanced systems will the first to size, shape and material selectively detect other nanoparticles in solution, which is interesting for many types of colloidal nanotechnological applications.

• DFG Programme: Research Grants
• Major Instrumentation: Fluoreszenzspektrometer mit Lebensdauermessung
• Instrumentation Group: 1850 Spektralfluorometer, Lumineszenz-Spektrometer (außer Filterfluorometer