Event Title

Investigation of surface plasmon resonance biosensor sensitivity using Kretschmann ATR theory

Co-Author(s)

Sarah Clark, Valerie Beale, Karissa Langevin

Research Mentor(s)

Janelle Leger

Description

Surface plasmon resonance (SPR) is a phenomenon that is frequently employed in biosensing devices. SPR occurs when an incident photon couples to charge density oscillations on a metal surface, exciting a surface plasmon polariton (SPP). SPPs are interface-confined modes that propagate along metal-dielectric structures called waveguides. Attenuated total reflection (ATR) is a method in which a coupling prism is used to excite SPPs in a waveguide. Utilizing the excitation of SPPs by ATR, a SPR biosensor monitors binding interactions at the metal surface of a waveguide in real time, as binding results in a measurable shift in SPP excitation conditions. SPR biosensor performance is limited by low sensitivity of binding detection. Recent evidence suggests that sensitivity can be increased by using SPPs with high propagation lengths. In order to understand the relationship between SPP propagation and biosensor sensitivity, the theory behind SPP excitation in biosensors must be explored. SPR biosensors require the Kretschmann configuration of ATR in which the waveguide’s metal film is exposed for monitoring. While Kretschmann configuration is often used experimentally, comprehensive theoretical models for excitations in this configuration are lacking. Here we discuss development of the electromagnetic theory behind SPR biosensor excitations based off of experimental measurements. Our results show a positive correlation between SPP propagation lengths and biosensor sensitivity, indicating the potential for high sensitivity biosensors that use waveguides tuned to support high propagation SPPs.

Document Type

Event

Start Date

15-5-2019 9:00 AM

End Date

15-5-2019 5:00 PM

Location

Carver Gym (Bellingham, Wash.)

Department

Physics/Astronomy

Genre/Form

student projects, posters

Type

Image

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.

Language

English

Format

application/pdf

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May 15th, 9:00 AM May 15th, 5:00 PM

Investigation of surface plasmon resonance biosensor sensitivity using Kretschmann ATR theory

Carver Gym (Bellingham, Wash.)

Surface plasmon resonance (SPR) is a phenomenon that is frequently employed in biosensing devices. SPR occurs when an incident photon couples to charge density oscillations on a metal surface, exciting a surface plasmon polariton (SPP). SPPs are interface-confined modes that propagate along metal-dielectric structures called waveguides. Attenuated total reflection (ATR) is a method in which a coupling prism is used to excite SPPs in a waveguide. Utilizing the excitation of SPPs by ATR, a SPR biosensor monitors binding interactions at the metal surface of a waveguide in real time, as binding results in a measurable shift in SPP excitation conditions. SPR biosensor performance is limited by low sensitivity of binding detection. Recent evidence suggests that sensitivity can be increased by using SPPs with high propagation lengths. In order to understand the relationship between SPP propagation and biosensor sensitivity, the theory behind SPP excitation in biosensors must be explored. SPR biosensors require the Kretschmann configuration of ATR in which the waveguide’s metal film is exposed for monitoring. While Kretschmann configuration is often used experimentally, comprehensive theoretical models for excitations in this configuration are lacking. Here we discuss development of the electromagnetic theory behind SPR biosensor excitations based off of experimental measurements. Our results show a positive correlation between SPP propagation lengths and biosensor sensitivity, indicating the potential for high sensitivity biosensors that use waveguides tuned to support high propagation SPPs.