A system and method for detecting changes in the refractive index of a fluid in a small test volume. A change in the refractive index can indicate a change in the chemical composition of the fluid. The test volume has a depth comparable to or less than the wavelength of incident light. In one embodiment,...http://www.google.de/patents/US7267797?utm_source=gb-gplus-sharePatent US7267797 - Nanofabricated photon tunneling based sensor
