Toward Imaging Defect-Mediated Energy Transfer between Single Nanocrystal Donors and Single Molecule Acceptors

Journal Article · Tue Apr 04 00:00:00 EDT 2023 · Chemical & Biomedical Imaging

DOI:https://doi.org/10.1021/cbmi.3c00015· OSTI ID:1968384

Lustig, Danielle R.  ^[1]; Nilsson, Zach N.  ^[1]; Mulvey, Justin T.  ^[2]; Zang, Wenjie ^[3]; Pan, Xiaoqing  ^[4]; Patterson, Joseph P.  ^[5]; Sambur, Justin B.  ^[6]

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1. Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
2. Center for Complex and Active Materials, University of California, Irvine, Irvine, California 92697-2025, United States, Department of Materials Science and Engineering, University of California, Irvine, Irvine, California 92697-2025, United States
3. Department of Materials Science and Engineering, University of California, Irvine, Irvine, California 92697-2025, United States
4. Department of Materials Science and Engineering, University of California, Irvine, Irvine, California 92697-2025, United States, Irvine Materials Research Institute, University of California, Irvine, Irvine, California 92697-2025, United States, Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697-2025, United States
5. Center for Complex and Active Materials, University of California, Irvine, Irvine, California 92697-2025, United States, Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States, Department of Materials Science and Engineering, University of California, Irvine, Irvine, California 92697-2025, United States
6. Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States, School of Advanced Materials Discovery, Colorado State University, Fort Collins, Colorado 80523-1872, United States

Defect-mediated energy transfer is an energy transfer process between midgap electronic states in a semiconductor nanocrystal (NC) and molecular acceptors, such as fluorescent dye molecules. Super-resolution fluorescence microscopy represents an exciting technique for pinpointing the nanoscale positions of lattice defect sites in, for example, a micrometer-sized particle or thin film sample by spatially resolving the location of the acceptor dye molecules with nanometer resolution. Toward this goal, our group performed ensemble-level, time-resolved fluorescence spectroscopy measurements of ZnO NC/Alexafluor 555 (A555) mixtures and calculated that the emissive defect sites are located, on average, 0.5 nm from the NC surface [Nilsson, Z. N.; J. Chem. Phys. 2021, 154 (5), 054704]. However, ensemble-level measurements cannot spatially resolve the defect sites on single particles, nor can they distinguish between surface-adsorbed dye molecules that participate in the energy transfer (EnT) process from those that do not. In this work, we compared the photoluminescence intensity trajectories of 789 isolated, single ZnO NC donors to those of 73 non-specifically bound and five specifically bound ZnO NC/A555 pairs, where the donor and acceptor centroid positions were separated by a distance that was smaller than our localization precision (40 nm). We observed minor fluorescence intensity fluctuations in the donor and defect channels instead of clear anticorrelated intensity fluctuations, which could be explained by (1) the presence of multiple emissive defect sites per NC, (2) donor–acceptor separation distances slightly larger than the Förster radius (R0 = 3.1 nm; defined as the distance at which EnT is 50% efficient), and/or (3) poor dipole–dipole coupling. The single molecule imaging methodology we developed, an alternating ultraviolet–visible excitation sequence combined with multicolor photon detection, successfully distinguishes specifically bound and non-specifically bound NC/dye pairs and can be applied to study a wide range of hybrid NC/dye energy transfer systems.

• Research Organization: Colorado State Univ., Fort Collins, CO (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0023431
• OSTI ID: 1968384
• Alternate ID(s): OSTI ID: 1974536
• Journal Information: Chemical & Biomedical Imaging, Journal Name: Chemical & Biomedical Imaging Vol. 1 Journal Issue: 2; ISSN 2832-3637
• Publisher: American Chemical Society
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
defects
single molecule
FRET
super-resolution
ZnO
energy transfer