The Department of Materials Science and Engineering invites you to join us for an upcoming Seminar:

Cassandra Fraser

University of Virginia Department of Chemistry

"Light Emitting Boron Biomaterials for Imaging and Oxygen Sensing "

Date:  Monday, February 9th, 2009

Time: 4:00-5:00 PM

Refreshments: 3:30- 4:00 PM

Room: Wilsdorf 101

Abstract

Polymeric boron biomaterials are noted for their luminescence.

Recently we reported that difluoroboron dibenzoylmethane-polylactide

materials are multi-emissive. In the solid state they exhibit delayed

emission, namely unusual room temperature phosphorescence and

temperature sensitive delayed fluorescence in addition to the expected

intense fluorescence. Emission color tuning may be effected by ligand

modifications and a simple but powerful method involving the polymer

molecular weight. Polymer composition also affects photophysical

properties. In comparison to the common 2-photon dye, bodipy, these

materials do not require a heavy atom for room temperature

phosphorescence; however, introduction of heavy atoms into boron

diketonate materials facilitates intersystem crossing and increases

phosphorescence intensity. Methods for modulating relative singlet and

triplet intensities for "turn on" and ratiometric oxygen sensing will

be presented. These materials have been fabricated as nanoparticles

for use in biological imaging and oxygen sensing in cells, tissues and

in vivo vascular and tumor model systems.

Susan Hull

Undergraduate Records Coordinator

Department of Materials Science and Engineering

P.O. Box 400745

Charlottesville, Virginia   22904-4745

Wilsdorf Hall

395 McCormick Road

University of Virginia

sh7h@virginia.edu

434-243-2247

434-982-5660  (FAX)