Naomi J. Halas

Naomi J. Halas is a University Professor and the Stanley C. Moore Professor of Electrical and Computer Engineering at Rice University. She received her undergraduate degree from La Salle University in 1980, and her PhD from Bryn Mawr College in 1987. She was a graduate research fellow at IBM Yorktown and a postdoctoral fellow at AT&T Bell Laboratories. She was the first person to introduce structural control into the synthesis of metal nanoparticles to control their optical properties.  She pursues studies of nanophotonics and its applications in biomedicine, optoelectronics, chemical sensing, photocatalysis, and solar water treatment. She is the author of more than 350 refereed publications, has more than 25 issued patents, and has presented more than 600 invited talks. She co-founded Nanospectra Biosciences, a company offering ultralocalized photothermal therapies for cancer based on her nanoparticles, and co-founded Syzygy Plasmonics, a company currently deploying light-based chemical reactors for Hydrogen production based on photocatalyst particles originally invented in her laboratory. She is a member of the National Academy of Sciences, the National Academy of Engineering, the American Academy of Arts and Sciences, the Royal Danish Academy of Sciences and Letters, and the Royal Society of Chemistry (UK).

Plasmonic Nanoparticles for Sustainability and Societal Impact

Metallic nanoparticles, used since antiquity to impart intense, vibrant color into materials, then brought to scientific attention in the 19th century as “Faraday’s colloid”, have more recently become a central tool in the nanoscale manipulation of light. When excited by light, metallic nanoparticles undergo a coherent oscillation of their conduction electrons- known as a plasmon- which is responsible for their strong light-matter interactions and properties: they can be thought of as “optical antennas”. One result of light illuminating metal nanoparticles is strong photothermal heating, a property that we originally introduced into biomedicine for highly localized cancer therapy.  Now, years after their initial demonstration, this approach has been used in successful human trials for the precise and highly localized ablation of cancerous regions of the prostate, eliminating the deleterious side effects characteristic of conventional prostate cancer therapies.  A second outcome of illuminating metal nanoparticles is the generation of nonequilibrium, or “hot” electrons, that can drive chemical processes very efficiently. By coupling optical antennas and catalyst particles, one can transform heat-driven chemical reactions into photodriven reactions that proceed under surprisingly mild, low temperature conditions.  This new type of light-based catalyst- an antenna-reactor nanoparticle complex- can be utilized for remediating greenhouse gases, converting them to useful molecules for industry, or into benign chemicals for a cleaner planet.