Seminar of the Division of Biomedical Physicochemistry
Microsoft Teams
High-throughput discovery of upconverting & photon avalanching nanocrystals
Dr. Emory Chan
The Molecular Foundry, Lawrence Berkeley National Laboratory (USA)
Seminarium odbędzie się w trybie zdalnym przy użyciu programu Microsoft Teams. Osoby w domenie intibs.pl mogą dołączyć do zespołu Seminarium OFB przy użyciu kodu: 7aoxdkd. Pozostałe osoby proszone są o kontakt pod adresem
Streszczenie:
Lanthanide-doped nanomaterials exhibit complex photophysical dynamics that give rise to photon upconversion, which can be leveraged for applications in optoelectronics, in vivo sensing, and imaging through tissue. I will discuss the high-throughput, robot-assisted discovery and application of new classes of upconverting nanoparticles, including materials that utilize photon avalanche and energy looping mechanisms to non-linearly amplify excited state populations. These mechanisms, which can be initiated with 1064 nm light in thulium-doped NaYF4 nanoparticles, allow “energy-looping nanoparticles” (ELNPs) to be imaged through millimeters of brain tissue. By coupling ELNPs to the whispering gallery modes of polystyrene microspheres, the resonators achieve sufficient gain to exhibit continuous-wave, anti-Stokes lasing that is stable for hours at room temperature. These microlasers operate even in complex biological media such as serum and through tissue-mimicking phantoms. We reduce the dimensions and thresholds of upconverting nanoparticle lasers by tuning their compositions, shells, and by coupling them to plasmonic arrays. By tuning the doping and photophysics of ELNPs, we demonstrated first observation of single photon avalanching nanoparticles, whose giant nonlinear optical responses allow imaging with ~70 nm resolution, far below the diffraction limit.
