2D label-free imaging of resonant grating biochips in ultraviolet

Kristelle Bougot-Robin (1) , Jean-Luc Reverchon (1) , Michel Fromant (2) , Laurent Mugherli (2) , Pierre Plateau (2) , Henri Benisty (3)

1 Thales Research and Technology [Palaiseau]
2 BIOC - Laboratoire de Biochimie de l'Ecole polytechnique
3 Laboratoire Charles Fabry de l'Institut d'Optique / Naphel

2D images of label-free biochips exploiting resonant waveguide grating (RWG) are presented. They indicate sensitivities on the order of 1 pg/mm2 for proteins in air, and hence 10 pg/mm2 in water can be safely expected. A 320×256 pixels Aluminum-Gallium-Nitride-based sensor array is used, with an intrinsic narrow spectral window centered at 280 nm. The additional role of characteristic biological layer absorption at this wavelength is calculated, and regimes revealing its impact are discussed. Experimentally, the resonance of a chip coated with protein is revealed and the sensitivity evaluated through angular spectroscopy and imaging. In addition to a sensitivity similar to surface plasmon resonance (SPR), the RWGs resonance can be flexibly tailored to gain spatial, biochemical, or spectral sensitivity.

Domains: Optics [physics.optics]

Kristelle Bougot-Robin, Jean-Luc Reverchon, Michel Fromant, Laurent Mugherli, Pierre Plateau, et al.. 2D label-free imaging of resonant grating biochips in ultraviolet. Optics Express, 2010, 8 (11), pp.11472. ⟨10.1364/OE.18.011472⟩. ⟨hal-00567020⟩