Surface Plasmon Resonance (SPR) sensors

Surface plasmon (SP) is an evanescent surface electromagnetic wave caused by collective and coherent free electron oscillation at a metal-dielectric interface.

Surface plasmon resonance (SPR) including propagating (PSPR) and localized (LSPR) are observed in the continuous metal film and isolated metal nanostructure. The SP waves are excited by incident light and is confined to the metal-dielectric interface with an extension of only ~200 nm from the interface. Therefore, the resonant frequency is strongly sensitive to the refractive index variation at the interface. This property is used in bio and chemical sensor with high real time sensitivity detection based on section of wavelength shift in reflection or transmittance spectrum.


Propagated surface plasmon in a continuous noble metal slab excited by free-space incident light (electric field). Right: Electric field variation in Localized surface plasmon of a spherical noble metal nanoparticle.


SEM micrograph of the tapered nanohole array before annealing. The inset shows the tapered nanohole array after annealing.


Related Papers:

1. “Optical Properties and Liquid Sensitivity of Au-SiO2-Au Nanobelt Structure”, M. Irannejad, B. Cui, M. Yavuz, Plasmonics,2015

2. ”Gold Nanohole Array with Sub-1 nm Roughness by Annealing for Sensitivity Enhancement of Extraordinary Optical Transmission biosensorsJ. Zhang, M. Irannejad, M. Yavuz, B. Cui, Nanoscale Research Letters,,2015

3. “The Effects of Varying Dielectric Spacer Height in the Reflection Resonance Spectrum of Gold Nanorod-on-Mirror Grating Structure”, M. Irannejad, B. Cui, M. Yavuz, Plasmonics2015,

4. “Numerical study of optical behavior of nano-hole array with non-vertical sidewall profile”, M. Irannejad, J. Zhang, Mustafa Yavuz, B. Cui, Plasmonics, 2014

5. “Finite difference time domain (FDTD) study of light transmission through multi-hole nanostructure in metallic film”, M. Irannejad, M. Yavuz, B. Cui, Photonics Research, vol.1, No.4, 154-159,2013