El-Sayed, Mostafa A.

Biography:

Mostafa El-Sayed was born in Egypt where he received his B.Sc. He received his Ph.D.at Florida State University with Professor Michael Kasha. After doing postdoctoral work at Yale, Harvard and Caltech, he joined the faculty at UCLA. In 1994, he moved to Georgia Tech and became the Julius Brown Chair, Regent Professor and Director of the Laser Dynamic Lab.

El-Sayed and his group (over 70 Ph.D. students and over 40 Postdoctoral Fellows) have contributed to many areas of physical and material chemistry research. They have been involved in the development of new techniques such as magneto photo selection, picoseconds Raman spectroscopy and phosphorescence microwave double resonance spectroscopy. Using spectroscopic techniques, they have been able to answer fundamental questions regarding ultra-fast dynamical processes involving molecules, solids and photo biological systems. Since he moved to Georgia Tech, El-Sayed and his group became active in the study of the physical, chemical and photo thermal processes of metallic and semiconductor nano structures of different shapes and compositions. The shape dependent applications of the metallic nanoparticles in nano catalysis, nano motors as well as nano medicine ( in Cancer diagnoses and photo-thermal therapy) have been demonstrated.

El-Sayed has published over 520 peer-reviewed papers, gave over 45 special named lectures and over 250 invited talks at National and International meetings. He has served on numerous international and national committees such as the Advisory Boards of NSF and Basic Energy Sciences of DOE and the National Research Council Board of Chemical Sciences. Prof. El-Sayed has served as the Editor-in-chief of the Journal of Physical Chemistry (1980-2004) and as the U.S. Editor of the International Reviews in Physical Chemistry.

El-Sayed is an elected member of the U.S. National Academy of Science, and elected Fellow of the American Academy of Arts and Sciences, the AAAS and the American Physical Society.He has also received the 1990 King Faisal International Prize in Science and an Honorary Doctor of Philosophy degree from the Hebrew University. He has received a number of national awards such as the Fresenius, the Tolman, the Richard's medal, as well as other numerous local ACS section awards. In 2002, he received the ACS-APS Langmuir National Award in Chemical Physics. In 2007, he was named the Distinguished Professor of the year at Georgia Tech and was offered the Miller Visiting Professrship at the university of California at Berkeley.


Abstract:

1) Metallic Gold Is More Precious on The Nanometer Size Scale; Some Properties & Applications of Gold Nanoparticles of Different Shapes In Nanophotonics, Nanomotors and Nanomedicine:

Many new fields such as optoelectronics, sensors, nanocatalysis, nanomotors and nanomedecine use the new exciting properties of gold and silver nanoparticles. They absorb and scatter light orders of magnitudes stronger than other materials. This is due to the coherent surface plasmon oscillation of the free electrons in their conduction band. The strong scattering properties can be used in imaging and sensitive detection of cancer cells. The strong absorbed photon energy is rapidly converted into heat. This localized heating of the gold nanoparticles can lead to: its melting, its coherent lattice oscillation (can be used in nanophotonics), it can lead to rapid sublimation of its atoms (leading to its propulsion and flying away with jet velocities) or it can heat and melts attached cancer cells leading to their destruction and thus used in cancer therapy.

2) Colloidal Nanocatalysis, The Good and The Bad:

Our results on nanocatalysis using transition metal nanoparticles in colloidal solution of two reactions, a mild electron transfer reaction and a harsh Suzuki carbon-carbon coupling reaction will be discussed. I will also discuss the effect of annealing gold nanoparticles has on its catalytic activity There is definitely shape dependence of the activation energy of these reactions, and the nanoparticles with larger fraction of its atoms present at edges and on corners are found to have the lowest activation energy. We also found that the activation energy increases during the reaction as a result of shape changes, which tend to round out the edges and the corners. The effect of nanocatalysis on size is found to depend on the reaction studied. In some reactions, the size increases; while in others,it decreases. The reasons for these changes will be discussed.