Purdue
University scientists
have developed a method for stacking synthetic DNA and carbon nanotubes onto a
biosensor electrode, a development that may lead to more accurate measurements
for research related to diabetes and other diseases.
Standard sensors employ metal electrodes coated with
enzymes that react with compounds and produce an electrical signal that can be
measured. But the inefficiency of those sensors leads to imperfect
measurements.
Carbon nanotubes have been seen as a possibility for
improving sensor performance. The problem is that the materials are not fully
compatible with water, which limits their application in biological fluids.
Marshall Porterfield, a professor of agricultural and
biological engineering and biomedical engineering, and Jong Hyun Choi, an
assistant professor of mechanical engineering, have found a solution. Their findings,
reported in The Analyst, describe a
sensor that essentially builds itself.
“In the future, we will be able to create a DNA
sequence that is complementary to the carbon nanotubes and is compatible with
specific biosensor enzymes for the many different compounds we want to
measure,” Porterfield says. “It will be a self-assembling platform
for biosensors at the biomolecular level.”
Choi developed a synthetic DNA that will attach to the
surface of the carbon nanotubes and make them more water-soluble.
“Once the carbon nanotubes are in a solution, you
only have to place the electrode into the solution and charge it. The carbon
nanotubes will then coat the surface,” Choi says.
The electrode coated with carbon nanotubes will attract
the enzymes to finish the sensor’s assembly.
The sensor described in the findings was designed for
glucose. But Porterfield says it could be easily adapted for various compounds.
“You could mass produce these sensors for diabetes,
for example, for insulin management for diabetic patients,” Porterfield
says.
Porterfield says it may one day be possible to develop
other sensors using this technology that could lead to more personalized
medicines that could test in real time the effectiveness of drugs on their
targets as with cancer patients.
Porterfield will continue to develop biosensors to detect
different compounds.
