Abstract

Whatever the context (biotechnology, molecular biology), biochips are now considered as relevant systems to detect biological molecules. Recently, the idea target molecules can be captured at a functionalized fluid interface has been put forward to develop a new type of biochip called fluid biochip with novel perspectives. In particular, an inexpensive label free detection is possible thanks to a mechanical transduction based on the change of the rheological interfacial properties during the hybridization between probe and target molecules at the fluid interface. The relevance of such a device in the field of DNA detection is studied experimentally. A meniscus capillary wave net is promoted at the surface of a water sub-phase contained in cylindrical cell submitted to a vertical vibration. The geometry of the wave net, which is characterized by two optical techniques, demonstrates a sensitivity to the surface tension and to the rheological interfacial properties. This sensitivity is used to detect the presence and the nature of DNA strands (single or double stranded) captured at the interface. The first steps towards the miniaturisation of such a detection method will be presented as well.