초록 |
Ring-closed Rhodamine derivatives are non-fluorescent and colorless, whereas ring-opening one exhibits a strong fluorescence and pink color. Rhodamune b derivatives have been used as fluorescent chemosensors for metal ions, in which a spirolactam(non-fluorescent) rearranges ring to open. For the selective recognition of such a soft heavy metal ions such as Cu, Fe, Zn, Pb and Hg, a sulfur-based functional group was considered for the rhodamine derivation. A new Rhodamine derivative was synthesized using amino acids such as cystein, alanine acid, aspartic acid, containing S or CO2H as well as NH2 group which can form an lactom with rhodamine lacton ring. Several side chains were introduced neighboring the lactam ring to assist the ring-opening through selective metal ion-chelation. Fluorescent silica nanoparticles were developed by a chemical binding of the rhodamine derivative to reactive silica surface. The metal selectivity of silica particles will be discussed. |