Orientational imaging and tracking of single colloidal CdSe quantum dots by defocused microscopy

We have demonstrated the possibility to obtain the orientation of single CdSe quantum dots by optical defocused microscopy. At the single molecule level, it is a useful tool to analyse the modification of the spontaneous emission of a single emitter close to an interface, it could also be used to study processes such as energy transfer between a quantum dot and a fluorophore. In the field of biological detection, this technique could he employed to investigate the rotary motion of molecular motors