light
LET THERE BE
>> photochemistry
Professor of Chemistry Vaidhyanathan Ramamurthy – also known as Murthy – is a pioneer in the field of photochemistry – the chemical reactions, and physical behaviors, that occur when atoms or molecules absorb light. > During a still-thriving research career that has spanned close to 40 years, Murthy has investigated the use of light to induce chemical reactions. Specifically, he places molecules in very small spaces and shines light on them; the confined area limits the molecules’ reactivity, preventing the chemical reactions from producing unwanted side products. This work holds promise for development of light-based energy sources that are clean and renewable. > On sabbatical this year, Murthy has taken his photochemistry expertise across the globe. He spent two months in Tokyo as an International Fellow of the Japan Society for the Promotion of Science, and four months in India as a Fulbright-Nehru Distinguished Chair. In Japan, Murthy served as an advisor to the All Nippon Artificial Photosynthesis Project for Living Earth (AN APPLE), an initiative aimed at creating cost-effective solar energy solutions. > He is also furthering photochemistry in his role as a senior associate editor of Langmuir, a premier journal published by the American Chemical Society. > Several other faculty members in the College are engaged in photochemistry research – with broad applications.
DR. MARC KNECHT Associate Professor of Chemistry
DR. FRANCISCO RAYMO Professor of Chemistry and Director of the Laboratory for Molecular Photonics Professor Francisco Raymo designs tiny nanocarriers that facilitate energy transfer within cells.
Associate Professor Marc Knecht uses light to break down PCBs. RESEARCH DESCRIPTION:
Knecht uses metal oxide nanoparticles to degrade environmental pollutants using light. “The nanoparticles absorb the light and then they generate reactive species that degrade pollutants,” Knecht said. By putting metal nanoparticles on the surface of metal oxides, he is able to drive two reactions simultaneously. R E S E A R C H A P P L I C AT I O N :
Knecht is working toward sustainable approaches to environmental cleanup, creating mechanisms that can break down polychlorinated biphenyls, or PCBs, into less toxic substances. They could potentially be used to treat contaminated lakes, ground water, sediments, and more. S T U D E N T I N V O LV E M E N T:
Knecht’s research is being used in the College’s innovative integrated chemistry/biology labs for first-year students. The initiative – funded by the Howard Hughes Medical Institute – allows students in basic science courses to engage in authentic open-ended research. Instead of replicating experiments to achieve known results, they are on a true path to discovery. The students work with Knecht’s metal oxide particles, studying their properties as a function of their shape and their toxicity on C. elegans worms.
14 SPRING 2015
RESEARCH DESCRIPTION:
Raymo’s research focuses on the use of fluorescent probes to monitor processes at the cellular level. “Our molecules are designed to switch from a nonfluorescent state to a fluorescent form under illumination at an appropriate wavelength,” he said. He recently published a study in the Journal of the American Chemical Society on his work with nanoparticles that “swim” through the watery environment surrounding cells and then pass through membranes to transport materials into living cells. Just 15 nanometers in diameter, the nanocarriers facilitate energy transfer within cells. The acceptors, which receive the energy, emit a fluorescent glow. R E S E A R C H A P P L I C AT I O N :
Raymo’s nanocarriers have the potential to allow scientists to detect cancer cells, and then deliver drugs directly to these bodies, preventing damage to other cells. “The ability to deliver distinct species inside cells independently and force them to interact exclusively in the intracellular environment can evolve into a valuable strategy to activate drugs inside cells,” said Raymo. S T U D E N T I N V O LV E M E N T:
Raymo works extensively with students in his lab. “Most of the experiments are done by graduate students,” he said, adding that undergraduates also work with him each semester.