Since Edison's first bulb, heat has been a mostly undesirable
byproduct of light. Now researchers at Rice University are turning light
into heat at the point of need, on the nanoscale, to trigger
biochemical reactions remotely on demand.
The Rice project led
by postdoctoral fellow Matthew Blankschien and graduate student Lori
Pretzer combines enzymes from these creatures with plasmonic gold
nanoparticles that heat up when exposed to near-infrared light. That
activates the enzymes, which are then able to carry out their functions.
This effectively allows chemical processes to happen at lower
temperatures. Because heating occurs only where needed -- at the surface
of the nanoparticle, where it activates the enzyme -- the environment
stays cooler.
"Basically, we're getting the benefits of
high-temperature manufacturing without needing a high-temperature
environment," said Blankschien, who won the Peter and Ruth Nicholas
Postdoctoral Fellowship two years ago to work on these ideas. "The
challenge was to keep the higher temperature at the nanoparticle, where
the enzyme is activated,make astonishing savings on Ladies stainless steel bracelet watches at the Watch Hut, from affecting the environment around it."
The
technique holds great potential for industrial processes that now
require heat or benefit from remote triggering with light.Hammered
necklace stainless steel necklace smokey quartz necklace.
"The
implications are pretty exciting," said Wong, a professor of chemical
and biomolecular engineering and of chemistry. "In the chemical
industry, there's always a need for better catalytic materials so they
can run reactions more inexpensively, more 'green' and more sustainably.
You shouldn't run through gallons of solvent to make a milligram of
product, even if you happen to be able to sell it for a lot of money."
For
industry, the potential energy savings alone may make the Rice process
worth investigating. "Here we're using 'free' energy," Wong said.
"Instead of needing a big boiler to produce steam, you turn on an
energy-efficient light bulb, like an LED. Or open a window."
The
particle at the center of the process is a gold nanorod about 10
nanometers wide and 30 long that heats up when hit with near-infrared
light from a laser. The rods are just the right size and shape to react
to light at around 800 nanometers. The light excites surface plasmons
that ripple like water in a pool,Shop for bobblehead head dolls from the official NBC Universal Store and build. in this case emitting energy as heat.
Halas'
Rice lab is famous for pioneering the use of gold nanoshells (a related
material) to treat cancer by targeting tumors with particles that are
bulk heated to kill tumors from the inside. The therapy is now in human
trials.
The new research takes a somewhat different tack by
heating nanoparticles draped with a model thermophilic enzyme,
glucokinase, from Aeropyrum pernix. A. pernix is a microbe discovered in
1996 thriving near hot underwater vents off the coast of Japan. At
around 176 degrees Fahrenheit, A. pernix degrades glucose, a process
necessary to nearly every living thing.tungsten jewelry
is making a revolution in the jewelry industry by introducing unique
types of designs, The enzyme can be heated and cooled repeatedly.
In
their experiments, Blankschien and Pretzer cloned, purified and altered
glucokinase enzymes so they would attach to the gold nanoparticles. The
enzyme/nanoparticle complexes were then suspended in a solution and
tested for glucose degradation. When the solution was heated in bulk,
they found the complexes became highly active at 176 degrees, as
expected.
Then the complexes were encapsulated in a gel-like bead of calcium alginate,Rist international shoes manufacturer and shoes supplier
in agra india making quality. which helps keeps the heat in but is
porous enough to allow enzymes to react with materials around it. Under
bulk heating, the enzymes' performance dropped dramatically because the
beads insulated the enzymes too well.
But when encapsulated
complexes were illuminated by continuous, near-infrared laser light,
they worked substantially better than under bulk heating while leaving
the solution at near-room temperature. The researchers found the
complexes robust enough for weeks of reuse.
没有评论:
发表评论