Tia Keyes

Biography

Tia Keyes is full professor (Chair) of Physical Chemistry at the School of Chemical Sciences, where she has been a member of academic staff since 2002. Her research interests lie in the fields of molecular spectroscopy & photophysics and in supramolecular & interfacial chemistry. She is particularly interested in applications of these fields to biological problems, including cell imaging/environmental mapping, cell capture, sensing and membrane mimetics.
Tia’s research team (https://sites.google.com/dcu.ie/keyes-research-group/home) are based between the School of Chemical Sciences and the National Biophotonics and Imaging Platform Ireland (NBIPI) www.nbipireland.ie/ which is housed within The National Centre for Sensor Research www.ncsr.ie.  Tia is also a member of the Water Institute at DCU.

To date, Tia is author/co-author of over 210 publications in international peer reviewed journals and has supervised/co-supervised 27 graduate students to PhD completion well as 3 MScs.
Tia is a Fellow of the Royal Society of Chemistry and a Fellow of the Institute of Chemistry of Ireland.

Present and past collaborators include: Prof. Paul Murphy, NUIG, Prof Jim Rusling, University of Connecticut, Prof. Robert Forster, DCU, Prof. Alan M. Bond, Monash University, Australia, Dr Grace Morgan, UCD, Dr. James Rice, UCD. Dr. Tim McCormack, DKIT, Prof. Tony Wedd, University of Melbourne, Australia, Prof Niamh Moran RCSI, Dr Marc Devocelle, RCSI, Prof L Cronin, Univ Glasgow, UK, Prof. Mario Reuben, Univ. of Karlsruhe, Prof Conor Long, DCU, Prof Barry Lentz, University of North Carolina, Chapel Hill, Prof Emmanuel Iwuoha, Univ. of Western Cape, Prof Vickie McKee, Univ of Loughborough, Prof Jane Nelson.

Research Expertise

PhD Students

Select Publications

Phase partitioning, solvent-switchable BODIPY probes for high contrast cellular imaging and FCS
  Tia E. Keyes, Darragh O Connor, Aisling Byrne, Ciaran Dolan      2018      New Journal of Chemistry
Lipophilic BODIPY fluorphores, in which the BODIPY core bears pendant dipyrido[3,2-a:2′,3′-c]phenazine (Dppz) or naphthyridyl and cholesterol substituents were designed and prepared as lipid probes for both liposomes and live cell imaging. The probes are non-emissive in water but permeate both GUV and live cell membranes and provide high contrast fluorescence and lifetime imaging of membranous structures and lipid droplets in cells and are suitable for FCS measurements on lipid membranes. © 2018 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

 

Multimodal Super-resolution Optical Microscopy Using a Transition-Metal-Based Probe Provides Unprecedented Capabilities for Imaging Both Nuclear Chromatin and Mitochondria
  Sreejesh Sreedharan, Martin R Gill, Esther Garcia, Hiwa Saeed, Darren Robinson, Aisling Byrne, Ashley J. Cadby, Tia E. Keyes, Carl Smythe, Patrina Pellett, Jorge Bernardino de la Serna, James A Thomas      2017      Journal of the American Chemical Society
Detailed studies on the live cell uptake properties of a dinuclear membrane-permeable RuII cell probe show that, at low concentrations, the complex localizes and images mitochondria. At concentrations above ∼20 μM, the complex images nuclear DNA. Because the complex is extremely photostable, has a large Stokes shift, and displays intrinsic subcellular targeting, its compatibility with super-resolution techniques was investigated. It was found to be very well suited to image mitochondria and nuclear chromatin in two color, 2C-SIM, and STED and 3D-STED, both in fixed and live cells. In particular, due to its vastly improved photostability compared to that of conventional SR probes, it can provide images of nuclear DNA at unprecedented resolution.

 

Polypyridyl substituted BODIPY derivatives; Water switchable imaging probes that exhibit halogen substituent dependent localisation in live cells
  Ciarán Dolan, Aisling Byrne, Conor Long, Krzysztof Czamara, Agnieszka Kaczor, Malgorzata Baranskacd, Tia E. Keyes      2017      RSC Advances

The synthesis and photophysical properties of water responsive 1,10-phenanthrolyl and 2,2′-bipyridyl substituted BODIPY derivatives prepared as lipid probes for cell imaging are reported. These compounds exhibit intense emission in non-aqueous media that is reversibly extinguished in aqueous media. Halogen substitution at the BODIPY indacene core decreases the emission quantum yields and causes red spectral shifts of emission maxima of the order H > Br > I. The emission was quenched on binding of the phenanthrolyl or bipyridyl to cations Fe2+, Cu2+ and Zn2+. The origin of the water switching effect and the impact of halogen substitution was investigated by modelling the electronic structure of the fluorophore using DFT methods. All compounds showed excellent permeability to live cells and were found, under imaging conditions, to generally exhibit low cytotoxicity. The absence of emission in the aqueous environment facilitated the collection of high contrast images from membranous regions and lipid droplets in live cells. The staining pattern in HeLa cells was found to depend on halogen substitution. Across both bpy and phen derivatives the halogenated probes showed the strongest targeting of lipid droplets within cells whilst the parent unsubstituted compounds were more widely dispersed in the cytoplasm. Resonance Raman imaging was used to map the distribution of probes within the cell and confirmed that the compounds showed strong co-localisation with lipid rich regions of the cell.

 

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