Surface Plasmon Resonance

Surface Plasmon Resonance (SPR)By Raaj, William, and AngelaOutline1. Process

2. Scientific Concepts

3. Applications

ProcessDefinitions and OverviewAssociation and Dissociation PhasesData AnalysisSurface Plasmon Resonance: DefinitionsWhat is a Plasmon?A quantization of collective electron oscillation, a photon being a quantization of electromagnetic waves

What is resonance?The tendency of a system to oscillate at a higher amplitude at certain frequencies.

Overview:Surface Plasmon ResonanceDefinition: The collective oscillation of valence electrons of a solid, instigated by incident lightImage: Kretschmann ConfigurationDeveloped in 1980sLight is from a laser diode at a fixed wavelength

Association PhaseAnalyte (red dots) binds to the Ligand (blue structures)

All PhasesChange in angle of reflected beam as analyte is injected

Data AnalysisAssociation Phase, Dissociation Phase, and Curve of Results

Association and Dissociation Constants

Kd Dissociation ConstantKa Association Constant

Binding Constant (KD) = Kd / KaThe constant can determine the rate at whichone molecule binds with anotherScientific PrinciplesAttenuated Total ReflectionEvanescent FieldReaction Rates Onsager CoefficientAttenuated Total Reflection (ATR)SPR at ATR condition at angle betaThe electrons can only be excited by the light photons under conditions of ATRThere is a drop in the intensity of reflected ray

Plasmons produce an evanescent electromagnetic fieldAmplitude of the field decays exponentially with increasing distance from surfaceCan measure signal within 300nm of the surface

Evanescent Field

Mass Transport Limitation (MTL)Mass transport = the rate at which an analyte is delivered to the surfaceWhen the rate of analyte binding to a ligand is faster than mass transport, there is a mass transport limitation (MTL)Apparent association + dissociation rates are different from the actual ratesApplicationsAntibody-Antigen InteractionDNA HybridizationBacteriaDetection of Alcohol concentration-UBCANTIGEN-ANTIBODY INTERACTION

DNA HYBRIDIZATION

BACTERIA

DETECTION OF ALCOHOL CONCENTRATION UBC research Surface-plasmon resonance sensing of alcohol with electrodepositedpolythiophene and gold nanoparticle-oligothiophene lmsBryan C. Sih and Michael O. Wolf,David Jarvis and Jeff F. Young

Research for detecting alcohol vapour levels in the food,biomedical, and chemical industriesSPR is an effective method of detecting alcohol vapourlevels by binding them to gold nanoparticles

Sourceshttp://www.phas.ubc.ca/~nanolab/labfiles/GetPDFServlet_plasmon_sensor.pdfSurface-plasmon resonance sensing of alcohol with electrodepositedpolythiophene and gold nanoparticle-oligothiophene lmsBryan C. Sih and Michael O. Wolf

Liedberg, Bo; Nylander, Claes; Lunstrm, Ingemar (1983). "Surface plasmon resonance for gas detection and biosensing".Sensors and Actuators

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