1. SPR (Surface Plasmon Resonance) Portable Chemical Sensing Instruments Graduate Research Assistant: Mike Warren, mwarren@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

2. Collaboration with Karl Booksh, Department of Chemistry, Arizona State University Polychromatic Light Inlet Port Outlet Port Chemically sensitive coating Gold Interface layer Waveguide Dielectric Color Filter Photodiode (includes integrated optical computing) Silicon Substrate SPR (Surface Plasmon Resonance) Portable Chemical Sensing Instruments Target System: Side View

3. Chemically sensitive coating Waveguide Gold Interface layer Analog Photodiode Outputs time Digital Alarm Outputs SPR (Surface Plasmon Resonance) Portable Chemical Sensing Instruments Target System: Top View

4. 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

5. 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.

6. Signal Stream 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 SPR (Surface Plasmon Resonance) Portable Chemical Sensing Instruments LED Source Coated SPR Probe (Analyte Specific) Optical Fiber Uncoated SPR Probe (Reference) Photodiode array (with integrated optical computing for reference compensation) 1. n 1. n Virtual Point Array (minimum detection) Analyte concentration Optical Train Silicon/Analog Circuits Sensors