DARPA awards Georgia Tech $4.3m to develop biochemical sensors
10 Dec 2010
The US Defense Advanced Research Projects Agency (DARPA) has
awarded the Georgia Institute of Technology $4.3m to develop a new class
of sensors able to detect multiple biological and chemical threats
Using integrated photonics, the new class of sensors will be
capable of detecting chemical agents, such as toxins, pollutants and
trace gases, and biological agents, such as proteins, viruses and
antibodies, simultaneously on the same chip.
The sensors will have applications in clinical screening, drug
discovery, food safety, environmental monitoring and national
“The proposed sensors will detect multiple biological and
chemical threats on a compact integrated platform faster, less
expensively and more sensitively than the current state-of-the-art
sensors,” said Ali Adibi, a professor in the School of Electrical
and Computer Engineering at Georgia Tech.
The Defense Advanced Research Projects Agency (DARPA) is funding
a two-year $4.3 million center as one of its Centers in Integrated
Photonics Engineering Research (CIPhER), which investigate
innovative approaches that enable revolutionary advances in science,
devices or systems.
For its center, Georgia Tech is working with researchers from
Emory University; Massachusetts Institute of Technology; University
of California, Santa Cruz; and Yale University. The team also
includes industry collaborators Rockwell Collins, Kotura, Santur
Corporation and NanoRods.
To create an integrated chip that will simultaneously detect
multiple biological and chemical agents, the researchers need to
achieve three major goals:
- design and fabricate photonic and optomechanical structures
to sense differences in a sample’s refractive index, Raman
emission, fluorescence, absorption and mass;
- functionalize the sensor surface with coatings that chemical
and biological agents will attach to and create differences that
can be detected; and
- develop the sample preparation method and microfluidic
sample delivery device, and connect the device to the coated
Adibi is leading the first thrust, which is primarily focused on
fabricating the millimeter-square sensing structures and on-chip
spectrometers that will enable multiplexing — the detection of
multiple agents using the same sensing modules.
The sensors will detect changes in the refractive index, Raman
emission, fluorescence, absorption spectra and optomechanical
properties when a sample that includes specific biological or
chemical particles interacts with the sensor coatings. Combining
information obtained from the five different sensing modalities will
maximize the sensor specificity and minimize its false detection
rate, the researchers say.
“The goal is to achieve very high sensitivity for each modality
and investigate the advantages of each modality for different
classes of biological and chemical agents in order to develop a
clear set of guidelines for combining different modalities to
achieve the desired performance for a specific set of agents,”
Massachusetts Institute of Technology chemistry professor Timothy
Swager is leading the second part of this project, which aims to
design surface coatings that will achieve maximum sensor specificity
in detecting multiple biological and chemical agents.
“We plan to develop glycan-based surface coatings to sense
biological agents and polymer-based surface coatings to sense
chemical agents,” noted Adibi.
For the third thrust, which is being led by Massachusetts
Institute of Technology electrical engineering associate professor
Jongyoon Han, the researchers will develop optimal sample
preparation and delivery techniques. Their goal is to maximize the
biological or chemical particle concentration in the sample and
limit detection time to minutes.
“In two years, we hope to have a lab-on-a-chip system that
includes all of the sensing modalities with appropriate coatings and
microfluidic delivery,” said Adibi. “To show the feasibility of the
technology, we plan to demonstrate the high sensitivity and high
selectivity of each sensor individually and be able to use at least
two of the sensing modalities simultaneously to detect two or three
different chemical or biological agents.”