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Abstract

           This lecture was an introduction to Surface Plasmon Resonance (SPR) Sensors. It started out with an explanation of Coulomb's Law for the force between two charges. This lead to the concept of the electric field and with an applied electric field, a molecule becomes a polarized dipole. On a system for when measuring things on a sensor, an externally applied electric field is used. The dipole moment for one molecule becomes reversed. This means when an Electric field is applied to a group of dipoles, all of the internal charges cancel out, except for the surface molecules. A secondary electric field is also produced. However, for this to occur it must be in a dielectric medium. The SPR Sensor can then characterize how easily the molecule is polarized by the electric field. All biomolecules have the 1/e > H2O, so the optical biosensors take advantage of this property. It doesn't measure the mass directly. It measure the changes in the dielectric permittivity due to the presence of biomolecules on the sensor surface. In order to do this it needs a way to project the Electric Field to the test sample and a way to measure the change in the dielectric permittivity. The metal is highly lossy, so the laterally propagating Electromagnetic field loses its intensity rapidly as it runs parallel to the surface. For a fixed wavelength, though, SP modes are only excited for a particular angle of incidence.

Bio

My research group is focused on the application of sub-wavelength optical phenomena and fabrication methods to the development of novel devices and instrumentation for the life sciences. The group is highly interdisciplinary, with expertise in the areas of microfabrication, nanotechnology, computer simulation, instrumentation, molecular biology, and cell biology. In particular, we are working on biosensors based upon photonic crystal concepts that can either be built from low-cost flexible plastic materials, or integrated with semiconductor-based active devices, such as light sources and photodetectors, for high performance integrated detection systems.

Using a combination of micrometer-scale and nanometer-scale fabrication tools, we are devising novel methods and materials for producing electro-optic devices with nanometer-scale features that can be scaled for low-cost manufacturing. Many of our techniques are geared for compatibility with flexible plastic materials, leading to applications such as low cost disposable sensors, wearable sensors, flexible electronics, and flexible displays. Because our structures manipulate light at a scale that is smaller than an optical wavelength, we rely on computer simulation tools such as Rigorous Coupled Wave Analysis (RCWA) and Finite Difference Time Doman (FDTD) to model, design, and understand optical phenomena within photonic crystals and related devices.

In addition to fabricating devices, our group is also focused on the design, prototyping, and testing of biosensor instrumentation for high sensitivity, portability, and resolution. Advanced instruments enable high resolution imaging of biochemical and cellular interactions with the ability to monitor images of biochemical interactions as a function of time. Using the sensors and instrumentation, we are exploring new applications for optical biosensor technology including protein microarrays, biosensor/mass spectrometry systems, and microfluidics-based assays using nanoliter quantities of reagents. The methods and systems developed in the laboratory are applied in the fields of life science research, drug discovery, diagnostic testing, and environmental monitoring. -From Professor Cunningham's Faculty Profile

Cite this work

Researchers should cite this work as follows:

  • Brian Cunningham (2013), "[Illinois] ECE 416 SPR Sensors I," https://nanohub.org/resources/16956.

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Time

Location

University of Illinois at Urbana-Champaign, Urbana, IL

Submitter

NanoBio Node, Obaid Sarvana, George Daley

Tags

[Illinois] ECE 416 Lecture 15: Surface Plasmon Resonance (SPR) Sensors I
  • Surface Plasmon Resonance Biosensors 1. Surface Plasmon Resonance Bios… 0
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  • Dielectric Permittivity 2. Dielectric Permittivity 18.342305966801256
    00:00/00:00
  • Coulomb's Law Force between two charges 3. Coulomb's Law Force between tw… 38.676239623064838
    00:00/00:00
  • Electric Field Due to a Point Charge 4. Electric Field Due to a Point … 95.3270136863361
    00:00/00:00
  • Polarization of a molecule 5. Polarization of a molecule 132.01985640565402
    00:00/00:00
  • Polarization of a molecule 6. Polarization of a molecule 157.80401615436392
    00:00/00:00
  • 7. "mini" dipole moment for one m… 176.27439982050709
    00:00/00:00
  • neutral 8. neutral 204.90969261835315
    00:00/00:00
  • Apply E to a group of molecules 9. Apply E to a group of molecule… 214.08290329818263
    00:00/00:00
  • Apply E to a group of molecules Cancellation of internal charges 10. Apply E to a group of molecule… 243.33800762844962
    00:00/00:00
  • Apply E to group of molecules Cancellation of internal charges 11. Apply E to group of molecules … 257.84159748709897
    00:00/00:00
  • Dielectric Permittivity 12. Dielectric Permittivity 307.17859546780346
    00:00/00:00
  • To summarize 13. To summarize 378.95277092214496
    00:00/00:00
  • Refractive Index (n) 14. Refractive Index (n) 425.31467354722906
    00:00/00:00
  • Water Molecule: H2O Oxygen atom 15. Water Molecule: H2O Oxygen ato… 487.04790217635178
    00:00/00:00
  • An electric field gives a force to all the electrons in a molecule + + 16. An electric field gives a forc… 505.1463989230424
    00:00/00:00
  • 17. "Waving" Electric Field from L… 507.50168274624184
    00:00/00:00
  • Waving Electric Field Effect on Electrons in a Molecule 18. Waving Electric Field Effect o… 520.14583800762853
    00:00/00:00
  • What is protein? 19. What is protein? 538.36829706080323
    00:00/00:00
  • Protein size compared to a visible wavelength 20. Protein size compared to a vis… 565.88792910029167
    00:00/00:00
  • Detecting Molecules by Dielectric Permittivity 21. Detecting Molecules by Dielect… 584.482275072919
    00:00/00:00
  • What optical biosensors need 22. What optical biosensors need 634.810971505497
    00:00/00:00
  • Surface Plasmons & Surface Plasmon Resonance 23. Surface Plasmons & Surface Pla… 662.45456585146962
    00:00/00:00
  • Surface Plasmons & Surface Plasmon Resonance 24. Surface Plasmons & Surface Pla… 741.54251738837775
    00:00/00:00
  • Surface Plasmon Resonance 25. Surface Plasmon Resonance 763.6078079425622
    00:00/00:00
  • Evanescent Field 26. Evanescent Field 809.59782364819387
    00:00/00:00
  • Effective Refractive Index 27. Effective Refractive Index 850.25746017500569
    00:00/00:00
  • Attenuation 28. Attenuation 886.33049136190255
    00:00/00:00
  • Surface Plasmon Excitation 29. Surface Plasmon Excitation 930.46107247027146
    00:00/00:00
  • Surface Plasmon Coupling Methods 30. Surface Plasmon Coupling Metho… 965.66636751177919
    00:00/00:00
  • Measurement of SP Resonant Coupling 31. Measurement of SP Resonant Cou… 1038.8041283374466
    00:00/00:00