Label-free biodetection by optical diffraction

Label-free biodetection techniques are the matter of intense research field in bioassays area. We have developed a label-free detection method based on optical diffraction. Probes molecules are immobilised on functionalized glass slides by soft lithography to generate molecular gratings that efficiently diffract light from a laser beam. Diffraction efficiency increases with the thickness of the molecular gratings. According to this principle, the measured diffraction intensity is found to increase when probe-target interactions take place at the surface of the molecular gratings. To collect and compare diffracted intensity before and after interaction, we have developed a dedicated scanner to measure the 1st order diffracted beam.



  • Label-free biodetection
  • Low-cost fabrication


  • Amandine M.C. Egea, Laurent Mazenq, Emmanuelle Trévisiole, Vincent Paveau and Christophe Vieu, Optical label free biodetection based on the diffraction of light by nanoscale protein gratings, Microelectronic Engineering, 2013, V.111, p.425-427


  • Patent : Jean-Christophe Cau, Helene Lalo, Jean-Pierre Peyrade, Childerick Severac and Christophe Vieu Method of seeking at least one analyte in a medium likely to contain it, 2010, WO 2010/029139


  • H. Lalo, Thèse INSA, Toulouse, 2009
  • J.C. Cau, Thèse INSA, Toulouse, 2009
  • J. Foncy, Thèse INSA, Toulouse, 2013