Biosensor Enhancement and Evaluation
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Georgia Tech’s biosensor technology uses a planar optical waveguide with interferometric detection methods for selective and
rapid quantitative measurement of microorganisms.
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Research Focus
The ATRP biosensor project further validated the latest detection assays
for selected pathogens and began engineering a next-generation multiplexed
sensor module that can be implemented as a process control tool within the
poultry processing environment.
The immunoassay protocol for rapid and sensitive
detection of Campylobacter jejuni using the interferometric waveguide
biosensor was optimized using a commercially available polyclonal antibody
as well
as monoclonal antibodies obtained from collaborators at the USDA.
Experiments were performed to test the sensitivity, selectivity, reproducibility,
and
regeneration capability of the immunoassay. Using a new sample delivery system
that incorporates a circulating loop, only 1 ml of solution is needed
for each assay. In collaboration with Michael Doyle (University of Georgia),
testing of viable (live) cultures of Campylobacter indicated greater
response than non-viable (heat-killed) organisms, with a limit of detection
of nearly
100 cfu/ml obtained.
The selectivity of the polyclonal anti-Campylobacter antibody
was assessed by competition from E.
coli, Salmonella, and Listeria, and no significant
response was observed at high levels of competition. The development
team also began focusing on the potential to use the sensor to
detect Avian Influenza (AI) and/or Exotic Newcastle
Disease (END) in the
field. Repeated assays (from concentrations of 103 to 107 cfu/ml)
were performed using independently prepared optical chips under identical
protocol conditions, and excellent chip-to-chip reproducibility (within
10%) was achieved.
In
addition, a mild treatment was found to provide regeneration of
the antibody sensing surface to allow repeated measurements using the
same
waveguide chip.
In collaboration with nGimat (the technology license holder)
and AIMSI (a systems integrator), initial design and testing of
components for
a new sensor prototype that incorporates a six-channel optical
chip
and a custom microlens array were begun.
The development team also
began focusing
on the potential to use the sensor to detect Avian Influenza
(AI) and/or Exotic Newcastle Disease (END) in the field. The team
established a collaborative
alliance with the Georgia Poultry Lab System and the Southeastern
Poultry Research Laboratory of the Agricultural Research Service
and participated on a multi-university submission to USDA to develop
new AI
screening
and
control techniques.
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