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Low-cost label-free biosensors using photonic crystals embedded between crossed polarizers

Low-cost label-free biosensors using photonic crystals embedded between crossed polarizers
Author:

Y. Nazirizadeh, U. Bog, S. Sekula, T. Mappes, U. Lemmer, M. Gerken 

links:
Source:

Opt. Express 18 (2010) 9120-9128 

Date: 2010

There is a strong need for low-cost biosensors to enable rapid, on-site analysis of biological, biomedical, or chemical substances. We propose a platform for label-free optical biosensors based on applying the analyte onto a surface-functionalized photonic crystal slab and performing a transmission measurement with two crossed polarization filters. This dark-field approach allows for efficient background suppression as only the photonic crystal guided-mode resonances interacting with the functionalized surface experience significant polarization rotation. We present a compact biosensor demonstrator using a low-cost light emitting diode and a simple photodiode capable of detecting the binding kinetics of a 2.5 nM solution of the protein streptavidin on a biotin-functionalized photonic crystal surface.