SPR (Surface Plasmon Resonance) Portable Chemical Sensing Instruments

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SPR (Surface Plasmon Resonance)Portable Chemical
Sensing Instruments
Graduate Research Assistant Mike Warren,
mwarren_at_u.washington.edu Funding Source
Subcontract to Arizona State University National
Science Foundation Grant Karl Booksh, Department
of Chemistry and BioChemistry (PI) 9/00-2/02
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SPR (Surface Plasmon Resonance)Portable Chemical
Sensing Instruments
Target System Side View
Polychromatic Light
Chemically sensitive coating Gold Interface
layer Waveguide Dielectric Color
Filter Photodiode (includes integrated optical
computing)
Inlet Port
Outlet Port
Silicon Substrate
Collaboration with Karl Booksh, Department of
Chemistry, Arizona State University
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SPR (Surface Plasmon Resonance)Portable Chemical
Sensing Instruments
Target System Top View
Analog Photodiode Outputs
time
Digital Alarm Outputs
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SPR (Surface Plasmon Resonance)Portable Chemical
Sensing Instruments

• Research Goals Short Term (First 18 months)
• Demonstrate Integrated Optical Computing for
  compensating any arbitrary reference environment
• Reduce output from photodetectors (directly) to
  the difference between the reference and present
  environment
• Extract two points from SPR array between which
  lies the minimum in the spectrum
• Use massively parallel, analog circuits to
  compute, in real-time the true minimum between
  these selected points
• Proof-of-concept compute (reference-independent)
  concentration directly from photodetectors and
  analog circuits in real-time using
  non-integrated SPR system

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SPR (Surface Plasmon Resonance)Portable Chemical
Sensing Instruments

• Research Goals Long Term (Years 2-4)
• Integrate SPR optical train onto a micromachined
  platform
• Develop dual probe system to track reference
  envionrment (bulk refractive index) and sensing
  environment (analyte-dependent refractive index)
  simulatenously
• Characterize resolution of minimum detection
  scheme (concentration limits)
• Demonstrate effective integration of optical
  train, photodetectors, and processing circuits
  onto a single chip.

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SPR (Surface Plasmon Resonance)Portable Chemical
Sensing Instruments
Optical Train
Sensors
Signal Stream
Silicon/Analog Circuits

• Advantages of this Approach
• Low-Cost
• Low-Power
• Small Space Requirements
• Low Imager Resolution Requirements
• Image Processing optimized to chemical
• Sensing application
• Automated Calibration
• Robustness to varying background levels

Optical Fiber
Analyte concentration