Phenothiazine-rhodamine-based colorimetric and fluorogenic 'turn-on' sensor for Zn and bioimaging studies in live cells.

A phenothiazine-rhodamine (PTRH) fluorescent dyad was synthesized and its ability to selectively sense Zn ions in solution and in in vitro cell lines was tested using various techniques. When compared with other competing metal ions, the PTRH probe showed the high selectivity for Zn ions that was supported by electronic and emission spectral analyses. The emission band at 528 nm for the PTRH probe indicated the ring closed form of PTRH, as for Zn ion binding to PTRH, the λ get shift to 608 nm was accompanied by a pale yellow to pink colour (under visible light) and green to pinkish red fluorescence emission (under UV light) due to ring opening of the spirolactam moiety in the PTRH ligand.

A Fluorescent Turn-On Carbazole-Rhodanine Based Sensor for Detection of Ag Ions and Application in Ag Ions Imaging in Cancer Cells.

Carbazole - Rhodanine conjugate is an effective fluorescent host for silver ions through fluorometric transformation from green to red color with a hyperchromic emission. An intramolecular charge transfer process derived from carbazole towards rhodanine favors interaction of thiocarbonyl S and carboxylic acid O of the rhodanine moiety towards Ag ion. Carbazole - rhodanine dyad accomplishes the lowest detection limit of 12.