Connecting Materials Science With Biology, K-State Engineers Create DNA Sensors That...

Connecting Materials Science With Biology, K-State Engineers Create DNA
Sensors That Could Identify Cancer Using Material Only One Atom Thick

MANHATTAN, Kan., April 13 /PRNewswire-USNewswire/ -- Kansas State University
engineers think the possibilities are deep for a very thin material.

Vikas Berry, assistant professor of chemical engineering, is leading research
combining biological materials with graphene, a recently developed carbon
material that is only a single atom thick.

"The biological interfacing of graphene is taking this material to the next
level," Berry said. "Discovered only four years ago, this material has already
shown a large number of capabilities. K-Staters are the first to do
bio-integrated research with graphene."

To study graphene, researchers rely on an atomic force microscope to help them
observe and manipulate these single atom thick carbon sheets.

"It's a fascinating material to work with," Berry said. "The most significant
feature of graphene is that the electrons can travel without interruptions at
speeds close to that of light at room temperature. Usually you have to go near
zero Kelvin -- that's about 450 degrees below zero Fahrenheit -- to get
electrons to move at ultra high speeds."

One of Berry's developments is a graphene-based DNA sensor. When electrons
flow on the graphene, they change speed if they encounter DNA. The researchers
notice this change by measuring the electrical conductivity. The work was
published in Nano-Letters.

"Most DNA sensors are optical, but this one is electrical," Berry said. "We
are currently collaborating with researchers from Harvard Medical School to
sense cancer cells in blood."

Another area he is exploring is loading graphene with antibodies and flowing
bacteria across the surface.

"Most researchers focus on pristine graphene, but we're making it dirty," he
said.

Berry and Nihar Mohanty, a graduate student in chemical engineering, used a
type of bacteria commonly found in rice and interfaced it with graphene. They
found that the graphene with tethered antibodies will wrap itself around an
individual bacterium, which remains alive for 12 hours.

Berry said that possible applications include a high-efficiency
bacteria-operated battery, where by using geobater, a type of bacteria known
to produce electrons, can be wrapped with graphene to produce electricity. The
research was presented at the annual American Physical Society conference in
Pittsburgh and the American Institute for Chemical Engineers conference in
Philadelphia.

"Materials science is an incredible field with several exploitable quantum
effects occurring at molecular scale, and biology is a remarkable field with a
variety of specific biochemical mechanisms," Berry said. "But for the most
part the two fields are isolated. If you join these two fields, the
possibilities are going to be immense. For example, one can think of a
bacterium as a machine with molecular scale components and one can exploit the
functioning of those components in a material device."

For his doctoral research, Berry used bacteria to make a humidity sensor.

"That was only possible through combining materials science with biological
science," he said.

Another area of his current research is compressing and stretching
molecular-junctions between nanoparticles. Berry said that his group has
developed a molecular-spring device where they can compress and stretch
molecules, which then act like springs, allowing researchers to study how they
relax back. He said that this technology could be used to create
molecular-timers in which the spring action from a decompressed molecule on a
chip could trigger a circuit, for instance.

Berry said for stretching the molecules, Kabeer Jasuja, a doctoral student in
chemical engineering, came up with the idea to place the device on a
centrifuge to stretch the molecules with centrifugal force.

The work was published in the journal, Small.

SOURCE Kansas State University

Erinn Barcomb-Peterson of Kansas State University, +1-785-532-6415,
ebarcomb@k-state.edu