1
|
Mitrikas G. Long Electron Spin Coherence Times of Atomic Hydrogen Trapped in Silsesquioxane Cages. J Phys Chem Lett 2023; 14:9590-9595. [PMID: 37862314 DOI: 10.1021/acs.jpclett.3c02626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
Encapsulated atomic hydrogen in cube-shaped octasilsesquioxane (POSS) cages of the Si8O12R8 type (where R is an organic group) is one of the simplest alternative stable systems to paramagnetic endofullerenes that have been regarded as key elements of spin-based quantum technologies. Apart from common sources of decoherence such as nuclear spin and spectral diffusion, all H@POSS species studied so far suffer from additional shortening of T2 at low temperatures due to methyl group rotations. Here we eliminate this factor for the first time by studying the smallest methyl-free derivative with R = H, namely, H@T8H8. By applying dynamical decoupling methods, we measure electron spin coherence times T2 up to 280 ± 76 μs at T = 90 K and observe a linear dependence of the decoherence rate 1/T2 on trapped hydrogen concentrations, which we attribute to the spin dephasing mechanism of instantaneous diffusion and a nonuniform spatial distribution of encapsulated H atoms.
Collapse
Affiliation(s)
- George Mitrikas
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, Aghia Paraskevi Attikis, Athens 15310, Greece
| |
Collapse
|
2
|
Sun L, Yang L, Dou JH, Li J, Skorupskii G, Mardini M, Tan KO, Chen T, Sun C, Oppenheim JJ, Griffin RG, Dincă M, Rajh T. Room-Temperature Quantitative Quantum Sensing of Lithium Ions with a Radical-Embedded Metal-Organic Framework. J Am Chem Soc 2022; 144:19008-19016. [PMID: 36201712 DOI: 10.1021/jacs.2c07692] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent advancements in quantum sensing have sparked transformative detection technologies with high sensitivity, precision, and spatial resolution. Owing to their atomic-level tunability, molecular qubits and ensembles thereof are promising candidates for sensing chemical analytes. Here, we show quantum sensing of lithium ions in solution at room temperature with an ensemble of organic radicals integrated in a microporous metal-organic framework (MOF). The organic radicals exhibit electron spin coherence and microwave addressability at room temperature, thus behaving as qubits. The high surface area of the MOF promotes accessibility of the guest analytes to the organic qubits, enabling unambiguous identification of lithium ions and quantitative measurement of their concentration through relaxometric and hyperfine spectroscopic methods based on electron paramagnetic resonance (EPR) spectroscopy. The sensing principle presented in this work is applicable to other metal ions with nonzero nuclear spin.
Collapse
Affiliation(s)
- Lei Sun
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois60439, United States
| | - Luming Yang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Jin-Hu Dou
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Jian Li
- Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56, Stockholm10044, Sweden
| | - Grigorii Skorupskii
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Michael Mardini
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States.,Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Kong Ooi Tan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States.,Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Tianyang Chen
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Chenyue Sun
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Julius J Oppenheim
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Robert G Griffin
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States.,Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Mircea Dincă
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Tijana Rajh
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois60439, United States.,The School for Molecular Sciences, Arizona State University, Tempe, Arizona85281, United States
| |
Collapse
|
3
|
Zaripov RB, Khairutdinov IT, Salikhov KM. Specific Features of Studying the Paramagnetic Relaxation of Spins by the Carr–Purcell–Meiboom–Gill Method Related to the Superposition of Echo Signals. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2021. [DOI: 10.1134/s1990793121030337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
4
|
Bottorf L, Sahu ID, McCarrick RM, Lorigan GA. Utilization of 13C-labeled amino acids to probe the α-helical local secondary structure of a membrane peptide using electron spin echo envelope modulation (ESEEM) spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2018; 1860:1447-1451. [PMID: 29694834 PMCID: PMC5957090 DOI: 10.1016/j.bbamem.2018.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 03/27/2018] [Accepted: 04/09/2018] [Indexed: 11/22/2022]
Abstract
Electron spin echo envelope modulation (ESEEM) spectroscopy in combination with site-directed spin labeling (SDSL) has been established as a valuable biophysical technique to provide site-specific local secondary structure of membrane proteins. This pulsed electron paramagnetic resonance (EPR) method can successfully distinguish between α-helices, β-sheets, and 310-helices by strategically using 2H-labeled amino acids and SDSL. In this study, we have explored the use of 13C-labeled residues as the NMR active nuclei for this approach for the first time. 13C-labeled d5-valine (Val) or 13C-labeled d6-leucine (Leu) were substituted at a specific Val or Leu residue (i), and a nitroxide spin label was positioned 2 or 3 residues away (denoted i-2 and i-3) on the acetylcholine receptor M2δ (AChR M2δ) in a lipid bilayer. The 13C ESEEM peaks in the FT frequency domain data were observed for the i-3 samples, and no 13C peaks were observed in the i-2 samples. The resulting spectra were indicative of the α-helical local secondary structure of AChR M2δ in bicelles. This study provides more versatility and alternative options when using this ESEEM approach to study the more challenging recombinant membrane protein secondary structures.
Collapse
Affiliation(s)
- Lauren Bottorf
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, United States
| | - Indra D Sahu
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, United States
| | - Robert M McCarrick
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, United States
| | - Gary A Lorigan
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, United States.
| |
Collapse
|
5
|
Breitgoff FD, Soetbeer J, Doll A, Jeschke G, Polyhach YO. Artefact suppression in 5-pulse double electron electron resonance for distance distribution measurements. Phys Chem Chem Phys 2018; 19:15766-15779. [PMID: 28590496 DOI: 10.1039/c7cp01488k] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A 5-pulse version of the Double Electron Electron Resonance (DEER) experiment with Carr-Purcell delays and an additional pump pulse has been shown to significantly extend the experimentally accessible distance range in cases where nuclear spin diffusion dominates electron spin phase memory loss [Borbat et al., J. Phys. Chem. Lett., 2013, 4, 170]. We show that the sequence also prolongs coherence decay for spin labels in or near lipid bilayers, where this decay is mono-exponential. Compared to 4-pulse DEER, 5-pulse DEER suffers from additional artefacts that stem from pulse imperfection and excitation band overlap. Only some of these artefacts can be suppressed by phase cycling and the remaining ones have hindered widespread utilization of the method. Here, we report previously unknown additional artefact contributions stemming from overlap between the excitation bands of the microwave pulses that introduce additional dipolar evolution pathways. Experimental conditions are analyzed in detail that suppress these as well as the already known artefacts. Such suppression results in data that contain at most the partial excitation artefact, which can be deliberately shifted in time by a change in pulse timing without affecting the wanted contribution.
Collapse
Affiliation(s)
- Frauke D Breitgoff
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland.
| | | | | | | | | |
Collapse
|
6
|
Doll A, Jeschke G. Double electron-electron resonance with multiple non-selective chirp refocusing. Phys Chem Chem Phys 2018; 19:1039-1053. [PMID: 27976758 DOI: 10.1039/c6cp07262c] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new approach to double electron-electron resonance (DEER) for distance determination involving nitroxide spin labels at dilute concentrations is presented. In general, DEER pulse sequences rely on double resonance between pump and observer spins excited by selective pulses at two distinct microwave frequencies. In the new approach abbreviated as nDEER, non-selective chirp pulses that refocus all relevant spin pairs are combined with DEER. This non-selective refocusing results in suppression of unmodulated contributions, such as the constant contribution as well as the background curvature due to inter-molecular spin partners in ordinary DEER data. Due to this dipolar attenuation effect, primary nDEER data are closer to the dipolar modulation of primary interest than ordinary DEER data. Restrictions of nDEER are that secondary information related to these unmodulated contributions becomes difficult to retrieve. Accordingly, incomplete deconvolution of the inter-molecular background prevents the application of nDEER to rigid spin pairs at high concentrations. A key advantage of nDEER is the high fidelity of the chirp refocusing pulses, which is important for nDEER schemes that incorporate dynamical decoupling to access longer distances. In this context, nDEER with Carr-Purcell (CP) pulse trains having N = 2 and N = 4 refocusing pulses are demonstrated. These CP nDEER sequences require a total of N + 2 pulses, which is less than the 2N + 1 pulses required for CP DEER schemes. The pump pulse position is incremented throughout the refocusing pulses, which restricts the minimum time increment to 96 ns on our spectrometer and therefore complicates application to distances below 3 nm. At Q-band frequencies, unwanted modulations related to pulse imperfections contribute only 3.5% relative to the principal nDEER modulation. Accordingly, there is no need for dedicated data reconstruction methods as in CP DEER methods.
Collapse
Affiliation(s)
- Andrin Doll
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland.
| | - Gunnar Jeschke
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland.
| |
Collapse
|
7
|
Soetbeer J, Hülsmann M, Godt A, Polyhach Y, Jeschke G. Dynamical decoupling of nitroxides in o-terphenyl: a study of temperature, deuteration and concentration effects. Phys Chem Chem Phys 2018; 20:1615-1628. [DOI: 10.1039/c7cp07074h] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Distinct matrix- and molecule dependencies govern nitroxide decoherence in o-terphenyl at low temperatures, disclosing an optimal range for dynamical decoupling.
Collapse
Affiliation(s)
- Janne Soetbeer
- Laboratory of Physical Chemistry
- ETH Zürich
- CH-8093 Zürich
- Switzerland
| | - Miriam Hülsmann
- Bielefeld University
- Department of Chemistry
- D-33615 Bielefeld
- Germany
| | - Adelheid Godt
- Bielefeld University
- Department of Chemistry
- D-33615 Bielefeld
- Germany
| | - Yevhen Polyhach
- Laboratory of Physical Chemistry
- ETH Zürich
- CH-8093 Zürich
- Switzerland
| | - Gunnar Jeschke
- Laboratory of Physical Chemistry
- ETH Zürich
- CH-8093 Zürich
- Switzerland
| |
Collapse
|
8
|
Zaripov R, Vavilova E, Khairuzhdinov I, Salikhov K, Voronkova V, Abdulmalic MA, Meva FE, Weheabby S, Rüffer T, Büchner B, Kataev V. Tuning the spin coherence time of Cu(II)-(bis)oxamato and Cu(II)-(bis)oxamidato complexes by advanced ESR pulse protocols. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:943-955. [PMID: 28546889 PMCID: PMC5433190 DOI: 10.3762/bjnano.8.96] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/29/2017] [Indexed: 06/07/2023]
Abstract
We have investigated with the pulsed ESR technique at X- and Q-band frequencies the coherence and relaxation of Cu spins S = 1/2 in single crystals of diamagnetically diluted mononuclear [n-Bu4N]2[Cu(opba)] (1%) in the host lattice of [n-Bu4N]2[Ni(opba)] (99%, opba = o-phenylenebis(oxamato)) and of diamagnetically diluted mononuclear [n-Bu4N]2[Cu(opbon-Pr2)] (1%) in the host lattice of [n-Bu4N]2[Ni(opbon-Pr2)] (99%, opbon-Pr2 = o-phenylenebis(N(propyl)oxamidato)). For that we have measured the electron spin dephasing time Tm at different temperatures with the two-pulse primary echo and with the special Carr-Purcell-Meiboom-Gill (CPMG) multiple microwave pulse sequence. Application of the CPMG protocol has led to a substantial increase of the spin coherence lifetime in both complexes as compared to the primary echo results. It shows the efficiency of the suppression of the electron spin decoherence channel in the studied complexes arising due to spectral diffusion induced by a random modulation of the hyperfine interaction with the nuclear spins. We argue that this method can be used as a test for the relevance of the spectral diffusion for the electron spin decoherence. Our results have revealed a prominent role of the opba4- and opbon-Pr24- ligands for the dephasing of the Cu spins. The presence of additional 14N nuclei and protons in [Cu(opbon-Pr2)]2- as compared to [Cu(opba)]2- yields significantly shorter Tm times. Such a detrimental effect of the opbon-Pr24- ligands has to be considered when discussing a potential application of the Cu(II)-(bis)oxamato and Cu(II)-(bis)oxamidato complexes as building blocks of more complex molecular structures in prototype spintronic devices. Furthermore, in our work we propose an improved CPMG pulse protocol that enables elimination of unwanted echoes that inevitably appear in the case of inhomogeneously broadened ESR spectra due to the selective excitation of electron spins.
Collapse
Affiliation(s)
- Ruslan Zaripov
- Kazan E. K. Zavoisky Physical -Technical Institute, Russian Academy of Sciences, 420029 Kazan, Russia
| | - Evgeniya Vavilova
- Kazan E. K. Zavoisky Physical -Technical Institute, Russian Academy of Sciences, 420029 Kazan, Russia
| | - Iskander Khairuzhdinov
- Kazan E. K. Zavoisky Physical -Technical Institute, Russian Academy of Sciences, 420029 Kazan, Russia
| | - Kev Salikhov
- Kazan E. K. Zavoisky Physical -Technical Institute, Russian Academy of Sciences, 420029 Kazan, Russia
| | - Violeta Voronkova
- Kazan E. K. Zavoisky Physical -Technical Institute, Russian Academy of Sciences, 420029 Kazan, Russia
| | - Mohammad A Abdulmalic
- Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Chemie, Straße der Nationen 62, D-09111 Chemnitz, Germany
| | - Francois E Meva
- Department of Pharmaceutical Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, BP 2701, Cameroon
| | - Saddam Weheabby
- Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Chemie, Straße der Nationen 62, D-09111 Chemnitz, Germany
| | - Tobias Rüffer
- Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Chemie, Straße der Nationen 62, D-09111 Chemnitz, Germany
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden, Germany
- Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden, Germany
| | - Vladislav Kataev
- Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden, Germany
| |
Collapse
|