Dark-field surface plasmon resonance microscopy

Dark-field microscopy in a surface plasmon resonance (SPR) scheme is introduced. A nanometre-thick patterned coating was imaged with SPR, and the image contrast was drastically enhanced when the zero diffraction order was eliminated. The resulting contrast is assigned to abrupt changes of the light phase with coating thickness, which are specific to SPR. The method offers prospects for highly sensitive multiple-spot biosensors.