RUI: A New Paradigm for the Design of Fluorescent Anion Sensors

University Of North Carolina At Wilmington, Wilmington NC

Investigators

Abstract

In this project funded by the Chemical Structure, Dynamics and Mechanism B program of the Chemistry Division, Professors Hee-Seung Lee and Robert Hancock of the Department of Chemistry and Biochemistry at the University of North Carolina, Wilmington are developing new types of sensors that emit light in the presence of specific ions. In particular, they are exploring a new design principle for efficient "turn-on" fluorescent sensors that exploits a fluorescent molecule competing with the anion for an interaction with a metal atom. The project brings together various subfields of chemistry and provides many opportunities for undergraduate students to participate in high level research. Fluorescent probes have become indispensable tools in modern biology and biotechnology because they provide real time information concerning the quantity of ions or molecules of interest within the living cell. Thus, the anion sensors developed in this project may spur significant advances in our understanding of cell biology. In tethered fluorescence sensors, a key factor in quenching fluorescence is metal-fluorophore pi-contact. Disruption of these pi-contacts by coordination of target anions leads to restoration of fluorescence that can be exploited to develop efficient "turn-on" anion sensors. New ligands are being synthesized and the complexes of these ligands with a variety of metal ions are being evaluated as the basis of anion sensors. Different fluorophores are being examined to identify their ability to form pi-contacts with metal ions. Anions of biological, biomedical, and environmental interest such as nitrate are being studied. An integral part of this project is the use of density functional theory (DFT) and time-dependent DFT to understand the fluorescence quenching by metal ions and the ability of metal-ligand complexes to act as anion sensors.