(729g) Robust Optical Probes Based on Dye-Embedded Organosilica Brush Particles

Organic dye-enabled optical probes play an important role as microscopic contrast agents or tags in diverse areas, such as biological sensors, drug delivery and microarrays. Unfortunately, the optical characteristics of organic dyes are sensitive to environmental parameters such as embedding medium, temperature, as well as presence of chemical agents such as acids or bases. This sensitivity can render the application of dyes difficult in applications in which environmental conditions dynamically change or calibration cannot be obtained. A possible solution is the embedding of dye molecules into colloidal particles that act as ‘protective shell’ to preserve functionality of dyes.

This contribution will present a new approach for the synthesis of dye-functionalized transparent colloidal particles that can serve as robust optical probes in a variety of organic embedding media. Organic dyes based on GBC salt base are embedded within sub-5 nm organosilica hybrid particles with low optical scattering cross-section. Surface polymerization is shown to provide a route to dispersing particles in a variety of embedding media and to preserve the optical efficacy against temperature as well as chemical degradation. SANS analysis is used to elucidate the microstructure of the resulting core shell particle systems and to evaluate the distribution of dye within the colloidal matrix. It is expected that this new model system can be applied to other fluorescent dyes or and thus be applied in areas such as bioimaging, permanent staining and robust biomedical sensors.