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TitleFully Self-Assembled Silica Nanoparticle-Semiconductor Quantum Dot Supra-Nanoparticles and Immunoconjugates for Enhanced Cellular Imaging by Microscopy and Smartphone Camera.
Publication TypeJournal Article
Year of Publication2020
AuthorsDarwish, Ghinwa H., Jérémie Asselin, Michael V. Tran, Rupsa Gupta, Hyungki Kim, Denis Boudreau, and Russ W Algar
JournalACS Appl Mater Interfaces
Date Published2020 Jul 29

There is a growing need for brighter luminescent materials to improve the detection and imaging of biomarkers. Relevant contexts include low-abundance biomarkers and technology-limited applications, where an example of the latter is the emerging use of smartphones and other nonoptimal but low-cost and portable devices for point-of-care diagnostics. One approach to achieving brighter luminescent materials is incorporating multiple copies of a luminescent material into a larger supra-nanoparticle (supra-NP) assembly. Here, we present a facile method for the preparation and immunoconjugation of supra-NP assemblies (SiO@QDs) that comprised many quantum dots (QDs) around a central silica nanoparticle (SiO NP). The assembly was entirely driven by spontaneous affinity interactions between the constituent materials, which included imidazoline-functionalized silica nanoparticles, ligand-coated QDs, imidazole-functionalized dextran, and tetrameric antibody complexes (TACs). The physical and optical properties of the SiO@QDs were characterized at both the ensemble and single-particle levels. Notably, the optical properties of the QDs were preserved upon assembly into supra-NPs, and single SiO@QDs were approximately an order of magnitude brighter than single QDs and nonblinking. In proof-of-concept applications, including selective immunolabeling of breast cancer cells, the SiO@QDs provided higher sensitivity and superior signal-to-background ratios whether using research-grade fluorescence microscopy or smartphone-based imaging. Overall, the SiO@QDs are promising materials for enhanced bioanalysis and imaging.

Alternate JournalACS Appl Mater Interfaces
PubMed ID32672938