1
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Liisberg MB, Vosch T. Fluorescence Screening of DNA-AgNCs with Pulsed White Light Excitation. NANO LETTERS 2024; 24:7987-7991. [PMID: 38905483 PMCID: PMC11229690 DOI: 10.1021/acs.nanolett.4c01561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 06/17/2024] [Accepted: 06/18/2024] [Indexed: 06/23/2024]
Abstract
DNA-stabilized silver nanoclusters (DNA-AgNCs) are a class of fluorophores with interesting photophysical properties dominated by the choice of DNA sequence. Screening methods with ultraviolet excitation and steady state well plate readers have previously been used for deepening the understanding between DNA sequence and emission color of the resulting DNA-AgNCs. Here, we present a new method for screening DNA-AgNCs by using pulsed white light excitation (λex ≈ 490-900 nm). By subtraction and time gating we are able to circumvent the dominating scatter of the white excitation light and extract both temporally and spectrally resolved emission of DNA-AgNCs over the visible to near-infrared range. Additionally, we are able to identify weak long-lived emission, which is often buried underneath the intense nanosecond fluorescence. This new approach will be useful for future screening of DNA-AgNCs (or other novel emissive materials) and aid machine-learning models by providing a richer training data set.
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Affiliation(s)
- Mikkel Baldtzer Liisberg
- Nanoscience Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Tom Vosch
- Nanoscience Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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2
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Guha R, Gonzàlez-Rosell A, Rafik M, Arevalos N, Katz BB, Copp SM. Electron count and ligand composition influence the optical and chiroptical signatures of far-red and NIR-emissive DNA-stabilized silver nanoclusters. Chem Sci 2023; 14:11340-11350. [PMID: 37886084 PMCID: PMC10599602 DOI: 10.1039/d3sc02931j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/09/2023] [Indexed: 10/28/2023] Open
Abstract
Near-infrared (NIR) emissive DNA-stabilized silver nanoclusters (AgN-DNAs) are promising fluorophores in the biological tissue transparency windows. Hundreds of NIR-emissive AgN-DNAs have recently been discovered, but their structure-property relationships remain poorly understood. Here, we investigate 19 different far-red and NIR emissive AgN-DNA species stabilized by 10-base DNA templates, including well-studied emitters whose compositions and chiroptical properties have never been reported before. The molecular formula of each purified species is determined by high-resolution mass spectrometry and correlated to its optical absorbance, emission, and circular dichroism (CD) spectra. We find that there are four distinct compositions for AgN-DNAs emissive at the far red/NIR spectral border. These emitters are either 8-electron clusters stabilized by two DNA oligomer copies or 6-electron clusters with one of three different ligand compositions: two oligomer copies, three oligomer copies, or two oligomer copies with additional chlorido ligands. Distinct optical and chiroptical signatures of 6-electron AgN-DNAs correlate with each ligand composition. AgN-DNAs with three oligomer ligands exhibit shorter Stokes shifts than AgN-DNAs with two oligomers, and AgN-DNAs with chlorido ligands have increased Stokes shifts and significantly suppressed visible CD transitions. Nanocluster electron count also significantly influences electronic structure and optical properties, with 6-electron and 8-electron AgN-DNAs exhibiting distinct absorbance and CD spectral features. This study shows that the optical and chiroptical properties of NIR-emissive AgN-DNAs are highly sensitive to nanocluster composition and illustrates the diversity of structure-property relationships for NIR-emissive AgN-DNAs, which could be harnessed to precisely tune these emitters for bioimaging applications.
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Affiliation(s)
- Rweetuparna Guha
- Department of Materials Science and Engineering, University of California Irvine CA 92697 USA
| | - Anna Gonzàlez-Rosell
- Department of Materials Science and Engineering, University of California Irvine CA 92697 USA
| | - Malak Rafik
- Department of Materials Science and Engineering, University of California Irvine CA 92697 USA
| | - Nery Arevalos
- Department of Materials Science and Engineering, University of California Irvine CA 92697 USA
| | - Benjamin B Katz
- Department of Chemistry, University of California Irvine CA 92697 USA
| | - Stacy M Copp
- Department of Materials Science and Engineering, University of California Irvine CA 92697 USA
- Department of Physics and Astronomy, University of California Irvine CA 92697 USA
- Department of Chemical and Biomolecular Engineering, University of California Irvine CA 92697 USA
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3
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Rück V, Liisberg MB, Mollerup CB, He Y, Chen J, Cerretani C, Vosch T. A DNA-Stabilized Ag 18 12+ Cluster with Excitation-Intensity-Dependent Dual Emission. Angew Chem Int Ed Engl 2023; 62:e202309760. [PMID: 37578902 DOI: 10.1002/anie.202309760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 08/16/2023]
Abstract
DNA-stabilized silver nanoclusters (DNA-AgNCs) are easily tunable emitters with intriguing photophysical properties. Here, a DNA-AgNC with dual emission in the red and near-infrared (NIR) regions is presented. Mass spectrometry data showed that two DNA strands stabilize 18 silver atoms with a nanocluster charge of 12+. Besides determining the composition and charge of DNA2 [Ag18 ]12+ , steady-state and time-resolved methods were applied to characterize the picosecond red fluorescence and the relatively intense microsecond-lived NIR luminescence. During this process, the luminescence-to-fluorescence ratio was found to be excitation-intensity-dependent. This peculiar feature is very rare for molecular emitters and allows the use of DNA2 [Ag18 ]12+ as a nanoscale excitation intensity probe. For this purpose, calibration curves were constructed using three different approaches based either on steady-state or time-resolved emission measurements. The results showed that processes like thermally activated delayed fluorescence (TADF) or photon upconversion through triplet-triplet annihilation (TTA) could be excluded for DNA2 [Ag18 ]12+ . We, therefore, speculate that the ratiometric excitation intensity response could be the result of optically activated delayed fluorescence.
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Affiliation(s)
- Vanessa Rück
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Mikkel B Liisberg
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Christian Brinch Mollerup
- Department of Forensic Medicine, University of Copenhagen, Frederik V's Vej 11, 2100, Copenhagen, Denmark
| | - Yanmei He
- Division of Chemical Physics and NanoLund, Lund University P.O. Box 124, 22100, Lund, Sweden
| | - Junsheng Chen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Cecilia Cerretani
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Tom Vosch
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
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4
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Rück V, Mishra NK, Sørensen KK, Liisberg MB, Sloth AB, Cerretani C, Mollerup CB, Kjaer A, Lou C, Jensen KJ, Vosch T. Bioconjugation of a Near-Infrared DNA-Stabilized Silver Nanocluster to Peptides and Human Insulin by Copper-Free Click Chemistry. J Am Chem Soc 2023. [PMID: 37441791 PMCID: PMC10402711 DOI: 10.1021/jacs.3c04768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/15/2023]
Abstract
DNA-stabilized silver nanoclusters (DNA-AgNCs) are biocompatible emitters with intriguing properties. However, they have not been extensively used for bioimaging applications due to the lack of structural information and hence predictable conjugation strategies. Here, a copper-free click chemistry method for linking a well-characterized DNA-AgNC to molecules of interest is presented. Three different peptides and a small protein, human insulin, were tested as labeling targets. The conjugation to the target compounds was verified by MS, HPLC, and time-resolved anisotropy measurements. Moreover, the spectroscopic properties of DNA-AgNCs were found to be unaffected by the linking reactions. For DNA-AgNC-conjugated human insulin, fluorescence imaging studies were performed on Chinese hamster ovary (CHO) cells overexpressing human insulin receptor B (hIR-B). The specific staining of the CHO cell membranes demonstrates that DNA-AgNCs are great candidates for bioimaging applications, and the proposed linking strategy is easy to implement when the DNA-AgNC structure is known.
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Affiliation(s)
- Vanessa Rück
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Narendra K Mishra
- Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Kasper K Sørensen
- Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Mikkel B Liisberg
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Ane B Sloth
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
- Cluster for Molecular Imaging, Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Cecilia Cerretani
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Christian B Mollerup
- Department of Forensic Medicine, University of Copenhagen, Frederik V's Vej 11, 2100 Copenhagen, Denmark
| | - Andreas Kjaer
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
- Cluster for Molecular Imaging, Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Chenguang Lou
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Knud J Jensen
- Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Tom Vosch
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
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5
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Wang X, Liisberg MB, Vonlehmden GL, Fu X, Cerretani C, Li L, Johnson LA, Vosch T, Richards CI. DNA-AgNC Loaded Liposomes for Measuring Cerebral Blood Flow Using Two-Photon Fluorescence Correlation Spectroscopy. ACS NANO 2023; 17:12862-12874. [PMID: 37341451 PMCID: PMC11065323 DOI: 10.1021/acsnano.3c04489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
Unraveling the transport of drugs and nanocarriers in cerebrovascular networks is important for pharmacokinetic and hemodynamic studies but is challenging due to the complexity of sensing individual particles within the circulatory system of a live animal. Here, we demonstrate that a DNA-stabilized silver nanocluster (DNA-Ag16NC) that emits in the first near-infrared window upon two-photon excitation in the second NIR window can be used for multiphoton in vivo fluorescence correlation spectroscopy for the measurement of cerebral blood flow rates in live mice with high spatial and temporal resolution. To ensure bright and stable emission during in vivo experiments, we loaded DNA-Ag16NCs into liposomes, which served the dual purposes of concentrating the fluorescent label and protecting it from degradation. DNA-Ag16NC-loaded liposomes enabled the quantification of cerebral blood flow velocities within individual vessels of a living mouse.
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Affiliation(s)
- Xiaojin Wang
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Mikkel B. Liisberg
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Georgia L. Vonlehmden
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, United States
| | - Xu Fu
- Light Microscopy Core, University of Kentucky, Lexington, Kentucky 40536, United States
| | - Cecilia Cerretani
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Lan Li
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Lance A. Johnson
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, United States
- Sanders Brown Center on Aging, University of Kentucky, Lexington, Kentucky 40508, United States
| | - Tom Vosch
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
- Nanoscience Center, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
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6
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Liasi Z, Hillers-Bendtsen AE, Jensen L, Mikkelsen KV. Elucidating the Mystery of DNA-Templating Effects on a Silver Nanocluster. J Phys Chem Lett 2023:5727-5733. [PMID: 37318362 DOI: 10.1021/acs.jpclett.3c00977] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
This presentation considers the effects that DNA-templating has on the optical properties of a 16-atom silver cluster. To accomplish this, hybrid quantum mechanical and molecular mechanical simulations of a Ag16-DNA complex have been carried out and compared with pure time-dependent density functional theory calculations of two Ag16 clusters in vacuum. The presented results show that the templating DNA polymers both red-shift the one-photon absorption of the silver cluster and increase its intensity. This occurs through a change in cluster shape prompted by the structural constraints of the DNA ligands combined with silver-DNA interactions. The overall charge of the cluster also contributes to the observed optical response, as oxidation of the cluster results in a simultaneous blue-shift of the one-photon absorption and a decrease in intensity. Additionally, the changes in shape and environment also lead to a blue-shift and enhancement of the two-photon absorption.
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Affiliation(s)
- Zacharias Liasi
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
| | | | - Lasse Jensen
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kurt V Mikkelsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
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7
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Ramasanoff RR, Sokolov PA. Intersystem Crossing Rates of Violet-, Green- and Red-emitting DNA Stabilized Silver Luminescent Clusters. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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8
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Liisberg MB, Krause S, Cerretani C, Vosch T. Probing emission of a DNA-stabilized silver nanocluster from the sub-nanosecond to millisecond timescale in a single measurement. Chem Sci 2022; 13:5582-5587. [PMID: 35694333 PMCID: PMC9116328 DOI: 10.1039/d2sc01137a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/21/2022] [Indexed: 12/14/2022] Open
Abstract
A method for measuring emission over a range of sub-nanosecond to millisecond timescales is presented and demonstrated for a DNA-stabilized silver nanocluster (DNA-AgNC) displaying dual emission. This approach allows one to disentangle the temporal evolution of the two spectrally overlapping signals and to determine both the nano- and microsecond decay times of the two emission components, together with the time they take to reach the steady-state equilibrium. Addition of a second near-infrared laser, synchronized with a fixed delay, enables simultaneous characterization of optically activated delayed fluorescence (OADF). For this particular DNA-AgNC, we demonstrate that the microsecond decay times of the luminescent state and the OADF-responsible state are similar, indicating that the OADF process starts from the luminescent state. A method for measuring emission over a range of sub-nanosecond to millisecond timescales is presented and demonstrated for a DNA-stabilized silver nanocluster (DNA-AgNC) displaying dual emission.![]()
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Affiliation(s)
- Mikkel Baldtzer Liisberg
- Nanoscience Center, Department of Chemistry, University of Copenhagen Universitetsparken 5 2100 Copenhagen Denmark
| | - Stefan Krause
- Nanoscience Center, Department of Chemistry, University of Copenhagen Universitetsparken 5 2100 Copenhagen Denmark
| | - Cecilia Cerretani
- Nanoscience Center, Department of Chemistry, University of Copenhagen Universitetsparken 5 2100 Copenhagen Denmark
| | - Tom Vosch
- Nanoscience Center, Department of Chemistry, University of Copenhagen Universitetsparken 5 2100 Copenhagen Denmark
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9
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Cerretani C, Palm-Henriksen G, Liisberg MB, Vosch T. The effect of deuterium on the photophysical properties of DNA-stabilized silver nanoclusters. Chem Sci 2021; 12:16100-16105. [PMID: 35024132 PMCID: PMC8672707 DOI: 10.1039/d1sc05079f] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/25/2021] [Indexed: 11/22/2022] Open
Abstract
We investigated the effect of using D2O versus H2O as solvent on the spectroscopic properties of two NIR emissive DNA-stabilized silver nanoclusters (DNA–AgNCs). The two DNA–AgNCs were chosen because they emit in the same energy range as the third overtone of the O–H stretch. Opposite effects on the ns-lived decay were observed for the two DNA–AgNCs. Surprisingly, for one DNA–AgNC, D2O shortened the ns decay time and enhanced the amount of µs-lived emission. We hypothesize that the observed effects originate from the differences in the hydrogen bonding strength and vibrational frequencies in the two diverse solvents. For the other DNA–AgNC, D2O lengthened the ns decay time and made the fluorescence quantum yield approach unity at 5 °C. We investigated the effect of using D2O versus H2O as solvent on the spectroscopic properties of two NIR emissive DNA-stabilized silver nanoclusters (DNA–AgNCs).![]()
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Affiliation(s)
- Cecilia Cerretani
- Department of Chemistry, University of Copenhagen Universitetsparken 5 Copenhagen 2100 Denmark
| | - Gustav Palm-Henriksen
- Department of Chemistry, University of Copenhagen Universitetsparken 5 Copenhagen 2100 Denmark
| | - Mikkel B Liisberg
- Department of Chemistry, University of Copenhagen Universitetsparken 5 Copenhagen 2100 Denmark
| | - Tom Vosch
- Department of Chemistry, University of Copenhagen Universitetsparken 5 Copenhagen 2100 Denmark
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10
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Petty JT, Carnahan S, Kim D, Lewis D. Long-lived Ag 10 6+ luminescence and a split DNA scaffold. J Chem Phys 2021; 154:244302. [PMID: 34241360 DOI: 10.1063/5.0056214] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular silver clusters emit across the visible to near-infrared, and specific chromophores can be formed using DNA strands. We study C4AC4TC3G that selectively coordinates and encapsulates Ag10 6+, and this chromophore has two distinct electronic transitions. The green emission is strong and prompt with ϕ = 18% and τ = 1.25 ns, and the near-infrared luminescence is weaker, slower with τ = 50 µs, and is partly quenched by oxygen, suggesting phosphorescence. This lifetime can be modulated by the DNA host, and we consider two derivatives of C4AC4TC3G with similar sequences but distinct structures. In one variant, thymine was excised to create an abasic gap in an otherwise intact strand. In the other, the covalent phosphate linkage was removed to split the DNA scaffold into two fragments. In relation to the contiguous strands, the broken template speeds the luminescence decay by twofold, and this difference may be due to greater DNA flexibility. These modifications suggest that a DNA can be structurally tuned to modulate metastable electronic states in its silver cluster adducts.
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Affiliation(s)
- Jeffrey T Petty
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, USA
| | - Savannah Carnahan
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, USA
| | - Dahye Kim
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, USA
| | - David Lewis
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, USA
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11
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Rück V, Cerretani C, Neacşu VA, Liisberg MB, Vosch T. Observation of microsecond luminescence while studying two DNA-stabilized silver nanoclusters emitting in the 800-900 nm range. Phys Chem Chem Phys 2021; 23:13483-13489. [PMID: 34109959 DOI: 10.1039/d1cp01731d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We investigated two DNA-stabilized silver nanoclusters (DNA-AgNCs) that show multiple absorption features in the visible region, and emit around 811 nm (DNA811-AgNC) and 841 nm (DNA841-AgNC). Both DNA-AgNCs have large Stokes shifts and can be efficiently excited with red light. A comparison with the commercially available Atto740 yielded fluorescence quantum yields in the same order of magnitude, but a higher photon output above 800 nm since both DNA-AgNCs are more red-shifted. The study of both DNA-AgNCs also revealed previously unobserved photophysical behavior for this class of emitters. The fluorescence quantum yield and decay time of DNA841-AgNC can be increased upon consecutive heating/cooling cycles. DNA811-AgNC has an additional absorption band around 470 nm, which is parallel in orientation to the lowest energy transition at 640 nm. Furthermore, we observed for the first time a DNA-AgNC population (as part of the DNA811-AgNC sample) with green and near-infrared emissive states with nanosecond and microsecond decay times, respectively. A similar dual emissive DNA-AgNC stabilized by a different 10-base DNA strand is also reported in the manuscript. These two examples highlight the need to investigate the presence of red-shifted microsecond emission for this class of emitters.
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Affiliation(s)
- Vanessa Rück
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
| | - Cecilia Cerretani
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
| | - Vlad A Neacşu
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
| | - Mikkel B Liisberg
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
| | - Tom Vosch
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark.
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12
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Gonzàlez-Rosell A, Cerretani C, Mastracco P, Vosch T, Copp SM. Structure and luminescence of DNA-templated silver clusters. NANOSCALE ADVANCES 2021; 3:1230-1260. [PMID: 36132866 PMCID: PMC9417461 DOI: 10.1039/d0na01005g] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 01/21/2021] [Indexed: 05/05/2023]
Abstract
DNA serves as a versatile template for few-atom silver clusters and their organized self-assembly. These clusters possess unique structural and photophysical properties that are programmed into the DNA template sequence, resulting in a rich palette of fluorophores which hold promise as chemical and biomolecular sensors, biolabels, and nanophotonic elements. Here, we review recent advances in the fundamental understanding of DNA-templated silver clusters (Ag N -DNAs), including the role played by the silver-mediated DNA complexes which are synthetic precursors to Ag N -DNAs, structure-property relations of Ag N -DNAs, and the excited state dynamics leading to fluorescence in these clusters. We also summarize the current understanding of how DNA sequence selects the properties of Ag N -DNAs and how sequence can be harnessed for informed design and for ordered multi-cluster assembly. To catalyze future research, we end with a discussion of several opportunities and challenges, both fundamental and applied, for the Ag N -DNA research community. A comprehensive fundamental understanding of this class of metal cluster fluorophores can provide the basis for rational design and for advancement of their applications in fluorescence-based sensing, biosciences, nanophotonics, and catalysis.
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Affiliation(s)
- Anna Gonzàlez-Rosell
- Department of Materials Science and Engineering, University of California Irvine California 92697-2585 USA
| | - Cecilia Cerretani
- Nanoscience Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5 2100 Copenhagen Denmark
| | - Peter Mastracco
- Department of Materials Science and Engineering, University of California Irvine California 92697-2585 USA
| | - Tom Vosch
- Nanoscience Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5 2100 Copenhagen Denmark
| | - Stacy M Copp
- Department of Materials Science and Engineering, University of California Irvine California 92697-2585 USA
- Department of Physics and Astronomy, University of California Irvine California 92697-4575 USA
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13
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Zhang Y, He C, Petty JT, Kohler B. Time-Resolved Vibrational Fingerprints for Two Silver Cluster-DNA Fluorophores. J Phys Chem Lett 2020; 11:8958-8963. [PMID: 33030904 DOI: 10.1021/acs.jpclett.0c02486] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
DNA-templated silver clusters are chromophores in which the nucleobases encode the cluster spectra and brightness. We describe the coordination environments of two nearly identical Ag106+ clusters that form with 18-nucleotide strands CCCCA CCCCT CCCX TTTT, with X = guanosine and inosine. For the first time, femtosecond time-resolved infrared (TRIR) spectroscopy with visible excitation and mid-infrared probing is used to correlate the response of nucleobase vibrational modes to electronic excitation of the metal cluster. A rich pattern of transient TRIR peaks in the 1400-1720 cm-1 range decays synchronously with the visible emission. Specific infrared signatures associated with the single guanosine/inosine along with a subset of cytidines, but not the thymidines, are observed. These fingerprints suggest that the network of bonds between a silver cluster adduct and its polydentate DNA ligands can be deciphered to rationally tune the coordination and thus spectra of molecular silver chromophores.
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Affiliation(s)
- Yuyuan Zhang
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Chen He
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, United States
| | - Jeffrey T Petty
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, United States
| | - Bern Kohler
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
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14
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Kacenauskaite L, Gabrielaitis D, Bærentsen N, Martinez KL, Vosch T, Laursen BW. Intrinsic anti-Stokes emission in living HeLa cells. PLoS One 2020; 15:e0230441. [PMID: 32176729 PMCID: PMC7075565 DOI: 10.1371/journal.pone.0230441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 02/29/2020] [Indexed: 11/18/2022] Open
Abstract
Intrinsic fluorescence of biological material, also called auto-fluorescence, is a well-known phenomenon and has in recent years been used for imaging, diagnostics and cell viability studies. Here we show that in addition to commonly observed auto-fluorescence, intrinsic anti-Stokes emission can also be observed under 560 nm or 633 nm excitation. The anti-Stokes emission is shown to be spatially located on/in the mitochondria. The findings presented here show that sensitive imaging experiments e.g. single molecule experiments or two-photon excitation imaging can be compromised if intracellular anti-Stokes emission is not accounted for. On the other hand, we suggest that this anti-Stokes emission could be exploited as an additional modality for mitochondria visualization and cell viability investigation even in systems that are already labeled with commonly used fluorophores that rely on normal Stokes-based detection.
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Affiliation(s)
- Laura Kacenauskaite
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| | - Dovydas Gabrielaitis
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai Bærentsen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Karen L. Martinez
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Tom Vosch
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Bo W. Laursen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
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15
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Cerretani C, Kondo J, Vosch T. Removal of the A10 adenosine in a DNA-stabilized Ag16 nanocluster. RSC Adv 2020; 10:23854-23860. [PMID: 35517326 PMCID: PMC9054913 DOI: 10.1039/d0ra02672g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 06/13/2020] [Indexed: 12/18/2022] Open
Abstract
The role of the terminal adenosine (A10) on the spectroscopic and structural properties of a previously described DNA-stabilized Ag16 nanocluster (DNA:Ag16NC) is presented. In the original DNA:Ag16NCs (5′-CACCTAGCGA-3′), the A10 nucleobase was involved in an Ag+-mediated interaction with an A10 in a neighboring asymmetric unit, and did not interact with the Ag16NC. Therefore, we synthesized AgNCs embedded in the corresponding 9-base sequence in order to investigate the crystal structure of these new DNA-A10:Ag16NCs and analyze the photophysical properties of the solution and crystalline state. The X-ray crystallography and spectroscopic measurements revealed that the 3′-end adenosine has little importance with respect to the photophysics and structure of the Ag16NCs. Additionally, the new crystallographic data was recorded with higher spatial resolution leading to a more detailed insight in the interactions between the nucleotides and Ag atoms. We investigated the effect of removing the A10 from 5′-CACCTAGCGA-3′ on the photophysical and structural properties of a DNA-stabilized Ag16NC.![]()
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Affiliation(s)
- Cecilia Cerretani
- Nanoscience Center and Department of Chemistry
- University of Copenhagen
- Copenhagen 2100
- Denmark
| | - Jiro Kondo
- Department of Materials and Life Sciences
- Sophia University
- 102-8554 Tokyo
- Japan
| | - Tom Vosch
- Nanoscience Center and Department of Chemistry
- University of Copenhagen
- Copenhagen 2100
- Denmark
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16
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Neacşu VA, Cerretani C, Liisberg MB, Swasey SM, Gwinn EG, Copp SM, Vosch T. Unusually large fluorescence quantum yield for a near-infrared emitting DNA-stabilized silver nanocluster. Chem Commun (Camb) 2020; 56:6384-6387. [DOI: 10.1039/d0cc01849j] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Silver nanoclusters stabilized by 5′-CCCGGAGAAG-3′ DNA strands display an unusually high fluorescence quantum yield in the near-infrared region.
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Affiliation(s)
- Vlad A. Neacşu
- Nanoscience Center and Department of Chemistry
- University of Copenhagen
- 2100 Copenhagen
- Denmark
| | - Cecilia Cerretani
- Nanoscience Center and Department of Chemistry
- University of Copenhagen
- 2100 Copenhagen
- Denmark
| | - Mikkel B. Liisberg
- Nanoscience Center and Department of Chemistry
- University of Copenhagen
- 2100 Copenhagen
- Denmark
| | | | | | - Stacy M. Copp
- Department of Materials Science and Engineering
- University of California
- Irvine
- USA
- Department of Physics and Astronomy
| | - Tom Vosch
- Nanoscience Center and Department of Chemistry
- University of Copenhagen
- 2100 Copenhagen
- Denmark
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17
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Gambucci M, Cerretani C, Latterini L, Vosch T. The effect of pH and ionic strength on the fluorescence properties of a red emissive DNA-stabilized silver nanocluster. Methods Appl Fluoresc 2019; 8:014005. [PMID: 31794430 DOI: 10.1088/2050-6120/ab47f2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
DNA-stabilized silver nanoclusters (DNA-AgNCs) are a class of promising fluorophores for imaging and sensing applications. All aspects of their spectroscopic properties are not yet fully characterized, leaving this field still with a number of fundamental studies to be addressed. In this work, we studied the spectroscopic properties of red-emitting DNA-AgNCs at different pH (5 to 9) and ionic strength μ (0.005 to 0.5). The photophysical properties of high performance liquid chromatography (HPLC) purified DNA-AgNCs proved to be constant over a large range of pH and μ, with absorption, emission and fluorescence decay times only being affected at very high pH and μ values. Non-purified DNA-AgNCs were also unaffected by pH and/or μ variations, but significant differences can be observed between the rotational correlation times of purified and non-purified DNA-AgNCs.
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Affiliation(s)
- Marta Gambucci
- Department of Chemistry, Biology and Biotechnology, Perugia University, Via Elce di sotto, 8, 06123 Perugia, Italy
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18
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Reveguk Z, Lysenko R, Ramazanov R, Kononov A. Ultrafast fluorescence dynamics of DNA-based silver clusters. Phys Chem Chem Phys 2019; 20:28205-28210. [PMID: 30397702 DOI: 10.1039/c8cp05727c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Atomic-level understanding of the nature of the electronically excited states in ligand-stabilized metal nanoclusters (NCs) is a prerequisite for the design of new NCs with desired properties. In this study, we investigate the emission dynamics of a Ag-DNA complex using the fluorescence up-conversion technique. We show that most of the relaxation from the Franck-Condon state to the emissive state takes place in less than 100 fs, in spite of a relatively large Stokes shift of 4500 cm-1. This relaxation is much faster than typical solvent/DNA relaxation rates. A further small relaxation occurs with time constants ranging from a few to hundreds of picoseconds. We also calculate the Stokes shift for model complexes of a small three-atom Ag3+ cluster with cytosine and guanine. The results of our calculations show that a substantial geometry change of the Ag3+ cluster is observed in the S1 state of both complexes, which results in Stokes shifts comparable with the experimental value. We conclude that the Stokes shift in the Ag-DNA complex arises mostly due to the change in the geometry of the Ag cluster in the excited state rather than to the solvent/DNA reorganization. Also, a different structure of the Ag-DNA complex ("dark cluster"), the excited state of which decays in 200 fs, is observed. The nature of this ultrafast deactivation is unclear, which requires further investigations.
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Affiliation(s)
- Zakhar Reveguk
- Saint-Petersburg State University, 199034 St. Petersburg, Russia.
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19
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Krause S, Cerretani C, Vosch T. Disentangling optically activated delayed fluorescence and upconversion fluorescence in DNA stabilized silver nanoclusters. Chem Sci 2019; 10:5326-5331. [PMID: 31191889 PMCID: PMC6540914 DOI: 10.1039/c9sc00865a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/23/2019] [Indexed: 12/20/2022] Open
Abstract
Optically activated delayed fluorescence (OADF) is a powerful tool for generating background-free, anti-Stokes fluorescence microscopy modalities. Recent findings, using DNA-stabilized silver nanoclusters (DNA-AgNCs), indicate that OADF is usually accompanied by a dark state-mediated consecutive photon absorption process leading to upconversion fluorescence (UCF). In this study, we disentangle the OADF and UCF process by means of wavelength-dependent NIR excitation spectroscopy. We demonstrate that, by appropriate choice of secondary NIR excitation wavelength, the dark state population can be preferentially depleted through OADF, minimizing the UCF contribution. These findings show that dark state depletion by OADF might enable background-free STED-like nanoscopy.
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Affiliation(s)
- Stefan Krause
- Nanoscience Center , Department of Chemistry , University of Copenhagen , Universitetsparken 5 , Copenhagen 2100 , Denmark . ;
| | - Cecilia Cerretani
- Nanoscience Center , Department of Chemistry , University of Copenhagen , Universitetsparken 5 , Copenhagen 2100 , Denmark . ;
| | - Tom Vosch
- Nanoscience Center , Department of Chemistry , University of Copenhagen , Universitetsparken 5 , Copenhagen 2100 , Denmark . ;
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20
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Cerretani C, Vosch T. Switchable Dual-Emissive DNA-Stabilized Silver Nanoclusters. ACS OMEGA 2019; 4:7895-7902. [PMID: 31459877 PMCID: PMC6693819 DOI: 10.1021/acsomega.9b00614] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 04/19/2019] [Indexed: 05/10/2023]
Abstract
We investigated an ss-DNA sequence that can stabilize a red- and a green-emissive silver nanocluster (DNA-AgNC). These two emitters can convert between each other in a reversible way. The change from red- to green-emitting DNA-AgNCs can be triggered by the addition of H2O2, while the opposite conversion can be achieved by the addition of NaBH4. Besides demonstrating the switching between red- and green-emissive DNA-AgNCs and determining the recoverability, we fully characterized the photophysical properties, such as steady-state emission, quantum yield, fluorescence lifetime, and anisotropy of the two emissive species. Understanding the mechanism behind the remarkable conversion between the two emitters could lead to the development of a new range of DNA-AgNC-based ratiometric sensors.
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21
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Fateminia SMA, Kacenauskaite L, Zhang CJ, Ma S, Manghnani PN, Chen J, Xu S, Hu F, Xu B, Laursen BW, Liu B. Simultaneous Increase in Brightness and Singlet Oxygen Generation of an Organic Photosensitizer by Nanocrystallization. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1803325. [PMID: 30480358 DOI: 10.1002/smll.201803325] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 10/22/2018] [Indexed: 06/09/2023]
Abstract
Efficient organic photosensitizers are attractive for cancer cell ablation in photodynamic therapy. Bright fluorescent photosensitizers are highly desirable for simultaneous imaging and therapy. However, due to fundamental competition between emission and singlet oxygen generation, design attempts to increase singlet oxygen generation almost always leads to the loss of fluorescence. Herein, it is shown for the first time that nanocrystallization enables a simultaneous and significant increase in the brightness and singlet oxygen generation of an organic photosensitizer. Spectroscopic studies show simultaneous enhancement in the visible light absorption and fluorescence after nanocrystallization. The enhanced absorption of visible light in nanocrystals is found to translate directly to the enhanced singlet oxygen production, which shows a higher ability to kill HeLa cells as compared to their amorphous counterpart.
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Affiliation(s)
- S M Ali Fateminia
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Laura Kacenauskaite
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Chong-Jing Zhang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, China
| | - Suqian Ma
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, China
| | - Purnima N Manghnani
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore
| | - Junsheng Chen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Shidang Xu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore
| | - Fang Hu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore
| | - Bin Xu
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, China
| | - Bo W Laursen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Bin Liu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore
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22
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Krause S, Carro-Temboury MR, Cerretani C, Vosch T. Probing heterogeneity of NIR induced secondary fluorescence from DNA-stabilized silver nanoclusters at the single molecule level. Phys Chem Chem Phys 2018; 20:16316-16319. [PMID: 29888362 DOI: 10.1039/c8cp02584c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In this communication, we investigate optically activated delayed fluorescence (OADF) from DNA-stabilized silver nanoclusters (DNA-AgNCs) at the single molecule level, and we probe the heterogeneity in the primary fluorescence (PF) intensity, NIR induced secondary fluorescence (SF) intensity and SF/PF ratio. Our experiments reveal a heterogeneous distribution in the SF/PF ratio, indicating that engineering of DNA-AgNCs towards a high SF/PF ratio and high OADF signal for background-free imaging might be possible.
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Affiliation(s)
- Stefan Krause
- Nanoscience Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark.
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