1. Concentration and pH-modulated dual fluorescence in self-assembled nanoparticles of phototautomerizable biopolymeric amphiphile From Chang-Keun Lim et.al. 2011 Journal: Dyes and Pigments Ingólfur Magnússon 29.05.2013

2. Introduction Luminescence based technologies have lead to great progress in biological and medical sciences. Aggregation triggered fluorescence modulation has gained increased interest recently In this study, a chitosan based biohybrid dye was synthesized The new chitosan biohybrid dye has the ability to self-probe its own molecular aggregation state with ratiometric fluorscence modulation

3. Introduction Phototautomerizable amphilic glycol chitosan (GC- HBO) Concentration, pH assembly behaviour and radiometric fluorescing characteristics of nanoaggregated ESPIT system was investigated ESPIT=Excited state intramolecular proton transfer

4. Methods 1 H NMR (300 MHz) UV and fluorescence Transmission electron microscopic (TEM) image Hydrodynamic size distribution determined by dynamic light scattering (DLS) pH dependence measurements performed in PBS (pH: 4,0-9,0) Following equation used to ratio of fluorescence intensities (R) :

5. Synthesis HBO= 2-(2-hydroxyphenyl)benzaxole HBO is a well known chromophore exhibiting enol-to-keto phototautomerization via ESIPT reaction

6. Synthesis

7. Results for GA-HBO H2OH2O THF

8. Results for CS-HBO

9. Results for GA-HBO

10. Conclusion A new polymeric biohybrid was synthesized According to the results the GS-HBO can self assemble into nanoparticles by chromophoric aggregation Chitosan biohybrids can be used to study the molecular aggregation behavior of self- assembled nanoparticles in an in vivo systems More characteristic data would be nice