EAGER: Single Quantum Dots via 2 Photon Excitation

 

This invention uses established two-photon microscopy techniques in combination with quantum-dots. Additionally, a spatial light modulator (or hologram) is used to split the light source into near diffraction limited spots (here, an array of 9x9: which increases the speed of imaging by 80X) and a piezoelectric stage is used to shift the hologram in the z axis (thereby allowing 3D imaging). This technology exploits the inherent properties of quantum dots, including most notably their extremely efficient response to two-photon excitation, being 10-100 times brighter than conventional flurophores. For example, photobleaching of quantum dots occurs at power nearly 20 times lower than that for organic dyes. This low power requirement allows for negligible sample heating and consequent destruction. Necessary to this success are anti-blinking reductants which allows for continuous emission by the q-dots.