Rhodamine-aminopyridine based fluorescent sensors for Fe3+ in water: Synthesis, quantum chemical interpretation and living cell application

Three compounds of rhodamine-triazine aminopyridine derivatives (sensor RC2P-RC4P) had been synthesized. Spectroscopic analyses revealed that differing structural substitution patterns of RC2P-RC4P resulted in different sensitivity for Fe3+ ions. Sensor RC2P due to having a suitable space coordination structure was more selective for Fe3+ over other metal ions and amino acids in water when compared with RC3P and RC4P. Density functional theory (DFT) calculations of RC2P-RC4P were carried out to rationalize the design. The detection limit of RC2P for Fe3+ was 4.1 x 10(-8) M, which presented a pronounced sensitivity toward Fe3+. In addition, a simple paper test strip for the rapid monitoring of Fe3+ was developed, and sensor RC2P was successfully applied to the imaging of Fe3+ in living HL-7702 cells. (C) 2015 Elsevier B.V. All rights reserved.