Correlating the photoluminescence (PL) properties of nanomaterials like semiconductor nanocrystals (QDs) and lanthanide-based upconversion nanocrystals (UCNPs) at the ensemble and single particle level is increasingly relevant for applications of these nanomaterials in the life sciences like bioimaging studies or their use as reporters in microfluidic assays. Aiming to derive particle architectures well suited for spectroscopic and microscopic applications, we compared the spectroscopic properties of different QDs like II/VI QDs and cadmium-free AIS/ZnS QDs as well as UCNPs of different chemical composition for particle ensembles and single particles. This included the PL spectra, fluorescence quantum yields (ΦF), brightness values, blinking behavior, and PL decay kinetics of these nanomaterials. Special emphasis was focused on measurements of the fluorescence quantum yield (ΦF) and brightness, that determine the signal size and provide a measure for the quality of nanocrystals like QDs and UCNPs which are prone to surface quenching and stabilized with coordinatively bound surface ligands. [1-3] In this respect, the potential of fluorescence correlation spectroscopy (FCS) for relative ΦF measurements of nanoparticles at ultralow concentration was explored exemplarily for ligand-stabilized CdTe nanocrystals in water. 
References. (1) Grabolle, M.; Spieles, M.; Lesnyak, V.; Gaponik, N.; Eychmüller, A.; Resch-Genger, U., Anal. Chem 2009, 81, 6285-6294. (2) Würth, C.; Grabolle, M.; Pauli, J.; Spieles, M.; Resch-Genger, U., Nat. Prot. 2013, 8, 1535-1550. (3) Kaiser, M.; Würth, C.; Kraft, M.; Hyppanen, I.;Soukka, T.; Resch-Genger, U., Nanoscale 2017, 9, 10051 - 10058. (4) Abbandonato, G.; Hoffmann, K.; Resch-Genger, U., Nanoscale 2018, 10, 7147-7154.
Ute Resch-Genger, Fluorian Weigert, Florian Frenzel, Christian Würth, Katrin Hoffmann, Irina Martynenko, and Lorena Dhamo, "Photoluminescence properties of different types of nanocrystals at the ensemble and single emitter level (Conference Presentation)," Proc. SPIE 10892, Colloidal Nanoparticles for Biomedical Applications XIV, 108920B (Presented at SPIE BiOS: February 02, 2019; Published: 4 March 2019); https://doi.org/10.1117/12.2511262.6008596922001.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the proceedings. They include the speaker's narration with video of the slides and animations. Most include full-text papers. Interactive, searchable transcripts and closed captioning are now available for most presentations.
Search our growing collection of more than 18,000 conference presentations, including many plenaries and keynotes.