Luminescent Transition Metal Complexes and Their Conjugates as Novel Cellular Probes and Imaging Reagents for Live Cells

This project aims to develop luminescent transition metal complexes and their conjugates as cellular probes and biological imaging reagents. Although fluorescent organic dyes and lanthanide chelates are commonly used as biological labels and probes, luminescent transition metal complexes have emerged as a new system for sensing and labelling biomolecules including DNA, peptides and proteins. The major advantages of these complexes include the high variety of molecular structures, and their rich photophysical and photochemical properties. Although the cytotoxicity and cellular uptake of these complexes have started to receive attention recently, the structureproperty relationship of these complexes, in terms of their cellular uptake mechanisms, intracellular trafficking pathways and organelle localizing selectivity, remains inconclusive in many cases. Also, the rich photophysical and photochemical properties of these complexes have not been utilized for diagnostic and therapeutic applications. Thus, an exciting area of research involves a systematic design of luminescent transition metal complexes as cellular probes and the exploitation of their emission properties in biological imaging. In this project, the researchers will develop new luminescent transition metal complexes and their conjugates with a variety of strategies including the use of functional ligands and macromolecular carriers. The photophysical, photochemical and electrochemical properties and lipophilicity of these complexes and their conjugates will be studied. Their cytotoxicity and uptake by mammalian cancer cell lines will also be investigated by bioassays, inductively-coupled plasma mass spectrometry, flow cytometry and fluorescence and laser-scanning confocal microscopy. Emphasis will be placed on understanding and exploiting the interactions of these complexes and their conjugates with various cellular components and structures. Ultimately, their potential use as cellular probes and biological imaging reagents for live cells will be examined.