ARC 11/02/10

Recent Advances in Surface Plasmon Resonance:From Biosensor to Space/astronomical Interest

Hololab and CSL

S. Habraken, C. Lenaerts, and J. Hastanin

ARC (11/02/10) 2

Surface Plasmon Resonance ?

incident angle, θ

Inte

nsit

y

E→ Z

I+++ - - -+++ - - -- - -

Dielectric

Metal

Evanescent wave

θ

SPR : Quantized oscillations of free electrons excited by an evanescent elm wave Reflectivity loss

ARC (11/02/10) 3

SPR excitation by coupling with elm wave

• How to produce the evanescent wave ?

1. ATR configuration (classical)

2. Grating based configuration(more recently)

Metallic filmPrism Grating

Metallic film

ARC (11/02/10) 4

Linked project:

• Plasmobio (Hololab, CSL, Univ. Mons and Lille)– Interreg project on micro bio fluidic and new architectures of SPR

sensors (http://biomems.iemn.univ-lille1.fr/fileadmin/groupe/Contrats/Plasmobio/Fiche_Presentation_Plasmobio.pdf )

Gold layer

m=1θSPR

Blazed Metallic gratings

Sample

Substrate

βm

α

nL=1,33

Tow

ards

D

etec

tor

TM; λ=760 nm

ARC (11/02/10) 5

Cantilever-based SPR

Laser

Gold Layer

Cantilever

Prism

PrismMetal

Cantilever FDTD modelization:

Electric Field Ex

Laser

hν

Cantilever bending induced by radiation absorption or

adsorption of chemical species

Bimorph cantilever with a semiconductor layer

ARC (11/02/10) 6

Cantilever-based SPR

Cantilever

Inicident angle

Gap thickness

Gap

Excitation efficiency is very sensitive to gap thickness

variation (up to 2 nm resolution !)

Possible Space Application: X-ray detector ( Anthony Hervé talk)Gas sensor (residual atmosphere on a planet)

ARC (11/02/10) 7

SPR Spectroscopy

• Basic Principle:– Spectral scanning instead of angular scanning !

Frozen angle with polychromatic light beam

• Some advantages: – High degree of freedom: for a specific application, optical parameters of

the layers can be determined independently and the highest resolution can be obtained

– High degree of miniaturization of SPR sensor optical imaging system, especially when coupling and dispersing are combined in the same element (grating)

ARC (11/02/10) 8

SPR based on Coupler and disperser Grating

Thin metal film grating Thick metal film grating

Principle: Coupling in +1order / Dispersing in -1order

Grating withthin metal coating

Diffraction order

Substrate

Liquid

θ

Diffraction order CCD CCD

θ

Liquid

Grating withthick metal coating

Substrate

Diffraction order

Detection in reflective mode

CCD

Detection in transmitive mode

ARC (11/02/10) 9

SPR based on Coupler and disperser Grating

Simulation: based on the rigorous elm theory : integral method (PC-Grate)

Typical results for thin metallic grating:

0

0,04

0,08

0,12

0,16

700 720 740 760 780 800 820 840

with asymmetrical grating interfaces such as:

Transmitive mode: Reflective mode:

0

0,2

0,4

0,6

760 780 800 820 840 860 880 900Eff

icie

ncy

of tr

ans.

ord

er m

=-1

Wavelength, nm

n liquid=1,38

n liquid=1,33

δλ=35-40 nm

Eff

icie

ncy

of r

efle

ct. o

rder

m=

-1

Wavelength, nmδλ=30-35 nm

n liquid=1,38

n liquid=1,33

ARC (11/02/10) 10

Conclusions

• SPR offers an intrinsic very high sensitivity

• Biomedical applications are under development with rapid worldwide advances (science and technology)

• Space/astronomical applications are related to:1. Detection of radiation or energetic particles

(see RX detector array with Anthony)

2. Detection of low concentration of fluid, especially gas molecules adsorbed on a functionalized layer: very high resolution and sensitivity with a miniaturized spectrometer: to be demonstrated…

• Great opportunity for synergy between biophotonics and astro !

ARC (11/02/10) 11

Annexe

Wavelength, nm

δλ=25-31 nm

n liquid=1,38

1000600

n liquid=1,33

0,3

Eff

icie

ncy

of r

efle

ct. o

rder

m=

-1