Two-photon absorbing (TPA) inorganic nanoparticles that are capable of upconverting near-infrared (NIR) light have the potential to enable a wide range of biophotonic applications, ranging from fluorescence imaging in live tissue to photodynamic therapy and clinical diagnostics. The synthesis of bright nanoparticle probes with large two-photon action cross-sections is still a major challenge. One strategy to increase the brightness of TPA nanoparticles is to excite a localized surface plasmon resonance (LSPR) that serves as virtual state for NIR photon absorption. I will present spectroscopic data for CuS nanodisks demonstrating that these colloidal semiconductor nanocrystals that support LSPRs in the NIR to mid-infrared wavelengths have the potential to exhibit extraordinary two-photon action cross-sections. We measure the two-photon action cross-sections for CuS nanodisks whose LSPR wavelengths are tuned on and off the NIR excitation wavelength. We also demonstrate that these TPA properties can be tuned to span a large range operating wavelengths covering the tissue transparency window. Overall, these colloidal semiconductor nanocrystals present a novel “all-in-one” structure for nonlinear optical processes since there is no physicochemical interface between plasmonic and photoluminescent components.

Enhanced two-photon photoluminescence with colloidal plasmonic semiconductor nanocrystals

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.