nets $25K prize
A few days after chemistry graduate student Rongchao Jin accidentally
left a beaker of silver colloid out in the lab, he and colleagues Gabriella
Métraux and Charles Cao realized that the yellow colloid had turned
blue under the fluorescent lights. They then developed a method to synthesize
the resulting silver nanoprisms, which exhibit unusual optical properties.
The discovery led to the trio winning a $25,000 prize in the annual Collegiate
Inventors Competition, sponsored by the National Inventors Hall of Fame. Jin,
Métraux, also a graduate student, and Cao, a former postdoctoral researcher
at Northwestern and now an assistant professor at the University of Florida,
worked with advisor Chad Mirkin, George B. Rathmann Professor of Chemistry. Mirkin
was recognized for his contributions with a $5,000 prize.
After their initial discovery of the colloid particles’ change in color,
Mirkin, Jin, Métraux and Cao found that the silver spheres interacted
with light and formed triangular silver nanoprisms. By varying the light sources,
they have created nanoparticles of different shapes and sizes, which changes
the particles’ optical, electrical, chemical and catalytic properties.
The intensely colored nanoparticles could be used for biological labeling, inks,
catalysts, specialized films and cosmetics, just to name a few applications.
“This team’s discovery is significant because the method uses light,
not heat, to induce chemical change, and it is done in a way that gives us remarkable
control over particle composition and size at the nanoscale,” said Mirkin.