1
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Rane V. Harnessing Electron Spin Hyperpolarization in Chromophore-Radical Spin Probes for Subcellular Resolution in Electron Paramagnetic Resonance Imaging: Concept and Feasibility. J Phys Chem B 2022; 126:2715-2728. [PMID: 35353514 DOI: 10.1021/acs.jpcb.1c10920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Obtaining a subcellular resolution for biological samples doped with stable radicals at room temperature (RT) is a long-sought goal in electron paramagnetic resonance imaging (EPRI). The spatial resolution in current EPRI methods is constrained either because of low electron spin polarization at RT or the experimental limitations associated with the field gradients and the radical linewidth. Inspired by the recent demonstration of a large electron spin hyperpolarization in chromophore-nitroxyl spin probe molecules, the present work proposes a novel optically hyperpolarized EPR imaging (OH-EPRI) method, which combines the optical method of two-photon confocal microscopy for hyperpolarization generation and the rapid scan (RS) EPR method for signal detection. An important aspect of OH-EPRI is that it is not limited by the abovementioned restrictions of conventional EPRI since the large hyperpolarization in the spin probes overcomes the poor thermal spin polarization at RT, and the use of two-photon optical excitation of the chromophore naturally generates the required spatial resolution, without the need for any magnetic field gradient. Simulations based on time-dependent Bloch equations, which took into account both the RS field modulation and the hyperpolarization generation by optical means, were performed to examine the feasibility of OH-EPRI. The simulation results revealed that a spatial resolution of up to 2 fL can be achieved in OH-EPRI at RT under in vitro conditions. Notably, the majority of the requirements for an OH-EPRI experiment can be fulfilled by the currently available technologies, thereby paving the way for its easy implementation. Thus, the proposed method could potentially bridge the sensitivity gap between the optical and magnetic imaging techniques.
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Affiliation(s)
- Vinayak Rane
- Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
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2
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Dayan N, Ishay Y, Artzi Y, Cristea D, Reijerse E, Kuppusamy P, Blank A. Advanced surface resonators for electron spin resonance of single microcrystals. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:124707. [PMID: 30599630 DOI: 10.1063/1.5063367] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/04/2018] [Indexed: 06/09/2023]
Abstract
Electron spin resonance (ESR) spectroscopy of paramagnetic species in single crystals is a powerful tool for characterizing the latter's magnetic interaction parameters in detail. Conventional ESR systems are optimized for millimeter-size samples and make use of cavities and resonators that accommodate tubes and capillaries in the range 1-5 mm. Unfortunately, in the case of many interesting materials such as enzymes and inorganic catalytic materials (e.g., zeolites), single crystals can only be obtained in micron-scale sizes (1-200 µm). To boost ESR sensitivity and to enable experiments on microcrystals, the ESR resonator needs to be adapted to the size and shape of these specific samples. Here, we present a unique family of miniature surface resonators, known as "ParPar" resonators, whose mode volume and shape are optimized for such micron-scale single crystals. This approach significantly improves upon the samples' filling factor and thus enables the measurement of much smaller crystals than was previously possible. We present here the design of such resonators with a typical mode dimension of 20-50 µm, as well as details about their fabrication and testing methods. The devices' resonant mode(s) are characterized by ESR microimaging and compared to the theoretical calculations. Moreover, experimental ESR spectra of single microcrystals with typical sizes of ∼25-50 µm are presented. The measured spin sensitivity for the 50-µm resonator at cryogenic temperatures of 50 K is found to be ∼1.8 × 106 spins/G √Hz for a Cu-doped single crystal sample that is representative of many biological samples of relevance.
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Affiliation(s)
- Nir Dayan
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Yakir Ishay
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Yaron Artzi
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - David Cristea
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Edward Reijerse
- Max-Planck-Institut fuer Chemische Energiekonversion, Stiftstrasse 34-36, 45470 Muelheim an der Ruhr, Germany
| | - Periannan Kuppusamy
- Department of Radiology and Medicine, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire 03756, USA
| | - Aharon Blank
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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3
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Matheoud AV, Sahin N, Boero G. A single chip electron spin resonance detector based on a single high electron mobility transistor. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 294:59-70. [PMID: 30005194 DOI: 10.1016/j.jmr.2018.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/03/2018] [Accepted: 07/04/2018] [Indexed: 06/08/2023]
Abstract
Single-chip microwave oscillators are promising devices for inductive electron spin resonance spectroscopy (ESR) experiments on nanoliter and subnanoliter samples. Two major problems of the previously reported designs were the large minimum microwave magnetic field (0.1-0.7 mT) and large power consumption (0.5-200 mW), severely limiting their use for the investigation of samples having long relaxation times and for operation at low temperatures. Here we report on the design and characterization of a single-chip ESR detector operating with a microwave magnetic field and a power consumption orders of magnitude lower compared with previous designs. These significant improvements are mainly due to the use of a high electron mobility transistor (HEMT) technology instead of a complementary metal-oxide semiconductor (CMOS) technology. The realized single-chip ESR detector, which operates at 11.2 GHz, consists of an LC Colpitts oscillator realized with a single high-electron mobility transistor and a co-integrated single turn planar coil having a diameter of 440 μm. The realized detector operates from 300 K down to 1.4 K, at least. Its minimum microwave magnetic field is 0.4 μT at 300 K and 0.06 μT at 1.4 K, whereas its power consumption is 90 μW at 300 K and 4 μW at 1.4 K, respectively. The experimental spin sensitivity on a sensitive volume of about 30 nL, as measured with a single crystal of α,γ-bisdiphenylene-β-phenylallyl (BDPA)/benzene complex, is of 8 × 1010 spins/Hz1/2 at 300 K and 2 × 109 spins/Hz1/2 at 10 K, respectively. In a volume of about 100 pL, located in proximity to the coil wire, the spin sensitivity improves by two orders of magnitude.
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Affiliation(s)
| | - Nergiz Sahin
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Giovanni Boero
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland.
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4
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Montinaro E, Grisi M, Letizia MC, Pethö L, Gijs MAM, Guidetti R, Michler J, Brugger J, Boero G. 3D printed microchannels for sub-nL NMR spectroscopy. PLoS One 2018; 13:e0192780. [PMID: 29742104 PMCID: PMC5942786 DOI: 10.1371/journal.pone.0192780] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/30/2018] [Indexed: 11/19/2022] Open
Abstract
Nuclear magnetic resonance (NMR) experiments on subnanoliter (sub-nL) volumes are hindered by the limited sensitivity of the detector and the difficulties in positioning and holding such small samples in proximity of the detector. In this work, we report on NMR experiments on liquid and biological entities immersed in liquids having volumes down to 100 pL. These measurements are enabled by the fabrication of high spatial resolution 3D printed microfluidic structures, specifically conceived to guide and confine sub-nL samples in the sub-nL most sensitive volume of a single-chip integrated NMR probe. The microfluidic structures are fabricated using a two-photon polymerization 3D printing technique having a resolution better than 1 μm3. The high spatial resolution 3D printing approach adopted here allows to rapidly fabricate complex microfluidic structures tailored to position, hold, and feed biological samples, with a design that maximizes the NMR signals amplitude and minimizes the static magnetic field inhomogeneities. The layer separating the sample from the microcoil, crucial to exploit the volume of maximum sensitivity of the detector, has a thickness of 10 μm. To demonstrate the potential of this approach, we report NMR experiments on sub-nL intact biological entities in liquid media, specifically ova of the tardigrade Richtersius coronifer and sections of Caenorhabditis elegans nematodes. We show a sensitivity of 2.5x1013 spins/Hz1/2 on 1H nuclei at 7 T, sufficient to detect 6 pmol of 1H nuclei of endogenous compounds in active volumes down to 100 pL and in a measurement time of 3 hours. Spectral resolutions of 0.01 ppm in liquid samples and of 0.1 ppm in the investigated biological entities are also demonstrated. The obtained results may indicate a route for NMR studies at the single unit level of important biological entities having sub-nL volumes, such as living microscopic organisms and eggs of several mammalians, humans included.
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Affiliation(s)
- E. Montinaro
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - M. Grisi
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - M. C. Letizia
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - L. Pethö
- Swiss Federal Laboratories for Materials Science and Technology (EMPA), Laboratory for Mechanics of Materials and Nanostructures, Thun, Switzerland
| | - M. A. M. Gijs
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - R. Guidetti
- University of Modena and Reggio Emilia, Department of Life Sciences, Modena, Italy
| | - J. Michler
- Swiss Federal Laboratories for Materials Science and Technology (EMPA), Laboratory for Mechanics of Materials and Nanostructures, Thun, Switzerland
| | - J. Brugger
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
| | - G. Boero
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Microsystems, Lausanne, Switzerland
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5
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Bouterfas M, Mouaziz S, Popovic RS. 14GHz longitudinally detected electron spin resonance using microHall sensors. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 282:47-53. [PMID: 28759742 DOI: 10.1016/j.jmr.2017.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/08/2017] [Accepted: 07/10/2017] [Indexed: 06/07/2023]
Abstract
In this work we developed a home-made LOngitudinally Detected Electron Spin Resonance (LODESR) spectrometer based on a microsize Hall sensor. A coplanar waveguide (CPW)-resonator is used to induce microwave-excitation on the sample at 14GHz. We used InSb cross-shaped Hall devices with active areas of (10μm×10μm) and (5μm×5μm). Signal intensities of the longitudinal magnetization component of DPPH and YIG samples of volumes about (10μm)3 and (5μm)3, are measured under amplitude and frequency modulated microwave magnetic field generated by the CPW-resonator. At room temperature, 109spins/G√Hz sensitivity is achieved for 0.2mT linewidth, a result which is still better than most of inductive detected LODESR sensitivities.
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Affiliation(s)
- M Bouterfas
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
| | - S Mouaziz
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - R S Popovic
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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6
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Matheoud AV, Gualco G, Jeong M, Zivkovic I, Brugger J, Rønnow HM, Anders J, Boero G. Single-chip electron spin resonance detectors operating at 50GHz, 92GHz, and 146GHz. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 278:113-121. [PMID: 28388496 DOI: 10.1016/j.jmr.2017.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 03/21/2017] [Accepted: 03/22/2017] [Indexed: 06/07/2023]
Abstract
We report on the design and characterization of single-chip electron spin resonance (ESR) detectors operating at 50GHz, 92GHz, and 146GHz. The core of the single-chip ESR detectors is an integrated LC-oscillator, formed by a single turn aluminum planar coil, a metal-oxide-metal capacitor, and two metal-oxide semiconductor field effect transistors used as negative resistance network. On the same chip, a second, nominally identical, LC-oscillator together with a mixer and an output buffer are also integrated. Thanks to the slightly asymmetric capacitance of the mixer inputs, a signal at a few hundreds of MHz is obtained at the output of the mixer. The mixer is used for frequency down-conversion, with the aim to obtain an output signal at a frequency easily manageable off-chip. The coil diameters are 120μm, 70μm, and 45μm for the U-band, W-band, and the D-band oscillators, respectively. The experimental frequency noises at 100kHz offset from the carrier are 90Hz/Hz1/2, 300Hz/Hz1/2, and 700Hz/Hz1/2 at 300K, respectively. The ESR spectra are obtained by measuring the frequency variations of the single-chip oscillators as a function of the applied magnetic field. The experimental spin sensitivities, as measured with a sample of α,γ-bisdiphenylene-β-phenylallyl (BDPA)/benzene complex, are 1×108spins/Hz1/2, 4×107spins/Hz1/2, 2×107spins/Hz1/2 at 300K, respectively. We also show the possibility to perform experiments up to 360GHz by means of the higher harmonics in the microwave field produced by the integrated single-chip LC-oscillators.
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Affiliation(s)
| | - Gabriele Gualco
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Minki Jeong
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Ivica Zivkovic
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Jürgen Brugger
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Henrik M Rønnow
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | | | - Giovanni Boero
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland.
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7
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Kiss SZ, Rostas AM, Heidinger L, Spengler N, Meissner MV, MacKinnon N, Schleicher E, Weber S, Korvink JG. A microwave resonator integrated on a polymer microfluidic chip. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 270:169-175. [PMID: 27497077 DOI: 10.1016/j.jmr.2016.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/16/2016] [Accepted: 07/18/2016] [Indexed: 06/06/2023]
Abstract
We describe a novel stacked split-ring type microwave (MW) resonator that is integrated into a 10mm by 10mm sized microfluidic chip. A straightforward and scalable batch fabrication process renders the chip suitable for single-use applications. The resonator volume can be conveniently loaded with liquid sample via microfluidic channels patterned into the mid layer of the chip. The proposed MW resonator offers an alternative solution for compact in-field measurements, such as low-field magnetic resonance (MR) experiments requiring convenient sample exchange. A microstrip line was used to inductively couple MWs into the resonator. We characterised the proposed resonator topology by electromagnetic (EM) field simulations, a field perturbation method, as well as by return loss measurements. Electron paramagnetic resonance (EPR) spectra at X-band frequencies were recorded, revealing an electron-spin sensitivity of 3.7·10(11)spins·Hz(-1/2)G(-1) for a single EPR transition. Preliminary time-resolved EPR experiments on light-induced triplet states in pentacene were performed to estimate the MW conversion efficiency of the resonator.
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Affiliation(s)
- S Z Kiss
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - A M Rostas
- Institute of Physical Chemistry (IPC), University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - L Heidinger
- Institute of Physical Chemistry (IPC), University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - N Spengler
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - M V Meissner
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - N MacKinnon
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - E Schleicher
- Institute of Physical Chemistry (IPC), University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - S Weber
- Institute of Physical Chemistry (IPC), University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - J G Korvink
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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8
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Aloisi G, Dolci D, Carlà M, Mannini M, Piuzzi B, Caneschi A. A capacitive probe for Electron Spin Resonance detection. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 263:116-121. [PMID: 26774649 DOI: 10.1016/j.jmr.2015.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 12/26/2015] [Accepted: 12/29/2015] [Indexed: 06/05/2023]
Abstract
The use of the magnetic field associated with Maxwell displacement current in a capacitor is proposed for the detection of Electron Spin Resonance. A probe based on this concept is realized and successfully tested with CW radio-frequency in the band going from 200MHz to 1GHz with a DPPH sample. A significant increase of Signal to Noise Ratio is observed while increasing the frequency.
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Affiliation(s)
- Giovanni Aloisi
- Department of Chemistry and INSTM Research Unit, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, FI, Italy.
| | - David Dolci
- Department of Chemistry and INSTM Research Unit, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, FI, Italy; Department of Physics, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino, FI, Italy
| | - Marcello Carlà
- Department of Physics, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino, FI, Italy
| | - Matteo Mannini
- Department of Chemistry and INSTM Research Unit, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, FI, Italy
| | - Barbara Piuzzi
- AllTek Innovation S.r.l., Piazza Divisione Julia 4, 33040 Corno di Rosazzo, UD, Italy
| | - Andrea Caneschi
- Department of Chemistry and INSTM Research Unit, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, FI, Italy
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9
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Franck JM, Barnes RP, Keller TJ, Kaufmann T, Han S. Active cancellation - A means to zero dead-time pulse EPR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 261:199-204. [PMID: 26507308 PMCID: PMC4688155 DOI: 10.1016/j.jmr.2015.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 06/25/2015] [Accepted: 07/05/2015] [Indexed: 05/02/2023]
Abstract
The necessary resonator employed in pulse electron paramagnetic resonance (EPR) rings after the excitation pulse and creates a finite detector dead-time that ultimately prevents the detection of signal from fast relaxing spin systems, hindering the application of pulse EPR to room temperature measurements of interesting chemical or biological systems. We employ a recently available high bandwidth arbitrary waveform generator (AWG) to produce a cancellation pulse that precisely destructively interferes with the resonant cavity ring-down. We find that we can faithfully detect EPR signal at all times immediately after, as well as during, the excitation pulse. This is a proof of concept study showcasing the capability of AWG pulses to precisely cancel out the resonator ring-down, and allow for the detection of EPR signal during the pulse itself, as well as the dead-time of the resonator. However, the applicability of this approach to conventional EPR experiments is not immediate, as it hinges on either (1) the availability of low-noise microwave sources and amplifiers to produce the necessary power for pulse EPR experiment or (2) the availability of very high conversion factor micro coil resonators that allow for pulse EPR experiments at modest microwave power.
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10
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Campbell JP, Ryan JT, Shrestha PR, Liu Z, Vaz C, Kim JH, Georgiou V, Cheung KP. Electron Spin Resonance Scanning Probe Spectroscopy for Ultrasensitive Biochemical Studies. Anal Chem 2015; 87:4910-6. [DOI: 10.1021/acs.analchem.5b00487] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Jason P. Campbell
- National Institute of Standards and Technology, 100 Bureau Drive, MS 8120, Gaithersburg, Maryland 20899, United States
| | - Jason T. Ryan
- National Institute of Standards and Technology, 100 Bureau Drive, MS 8120, Gaithersburg, Maryland 20899, United States
| | - Pragya R. Shrestha
- National Institute of Standards and Technology, 100 Bureau Drive, MS 8120, Gaithersburg, Maryland 20899, United States
| | - Zhanglong Liu
- National Institute of Standards and Technology, 100 Bureau Drive, MS 8120, Gaithersburg, Maryland 20899, United States
| | - Canute Vaz
- National Institute of Standards and Technology, 100 Bureau Drive, MS 8120, Gaithersburg, Maryland 20899, United States
| | - Ji-Hong Kim
- National Institute of Standards and Technology, 100 Bureau Drive, MS 8120, Gaithersburg, Maryland 20899, United States
| | - Vasileia Georgiou
- National Institute of Standards and Technology, 100 Bureau Drive, MS 8120, Gaithersburg, Maryland 20899, United States
- Department
of Electrical and Computer Engineering, George Mason University, 4400 University Drive, Fairfax, Virginia 22030, United States
| | - Kin P. Cheung
- National Institute of Standards and Technology, 100 Bureau Drive, MS 8120, Gaithersburg, Maryland 20899, United States
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11
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Narkowicz R, Suter D. Tuner and radiation shield for planar electron paramagnetic resonance microresonators. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:024701. [PMID: 25725864 DOI: 10.1063/1.4906898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Planar microresonators provide a large boost of sensitivity for small samples. They can be manufactured lithographically to a wide range of target parameters. The coupler between the resonator and the microwave feedline can be integrated into this design. To optimize the coupling and to compensate manufacturing tolerances, it is sometimes desirable to have a tuning element available that can be adjusted when the resonator is connected to the spectrometer. This paper presents a simple design that allows one to bring undercoupled resonators into the condition for critical coupling. In addition, it also reduces radiation losses and thereby increases the quality factor and the sensitivity of the resonator.
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Affiliation(s)
| | - Dieter Suter
- Fakultät Physik, TU Dortmund, 44221 Dortmund, Germany
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12
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Gualco G, Anders J, Sienkiewicz A, Alberti S, Forró L, Boero G. Cryogenic single-chip electron spin resonance detector. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 247:96-103. [PMID: 25261743 DOI: 10.1016/j.jmr.2014.08.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 08/12/2014] [Accepted: 08/25/2014] [Indexed: 06/03/2023]
Abstract
We report on the design and characterization of a single-chip electron spin resonance detector, operating at a frequency of about 20 GHz and in a temperature range extending at least from 300 K down to 4 K. The detector consists of an LC oscillator formed by a 200 μm diameter single turn aluminum planar coil, a metal-oxide-metal capacitor, and two metal-oxide-semiconductor field effect transistors used as negative resistance network. At 300 K, the oscillator has a frequency noise of 20 Hz/Hz(1/2) at 100 kHz offset from the 20 GHz carrier. At 4 K, the frequency noise is about 1 Hz/Hz(1/2) at 10 kHz offset. The spin sensitivity measured with a sample of DPPH is 10(8)spins/Hz(1/2) at 300 K and down to 10(6)spins/Hz(1/2) at 4 K.
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Affiliation(s)
- Gabriele Gualco
- Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jens Anders
- Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Andrzej Sienkiewicz
- Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Stefano Alberti
- Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - László Forró
- Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Giovanni Boero
- Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
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13
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Narkowicz R, Ogata H, Reijerse E, Suter D. A cryogenic receiver for EPR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 237:79-84. [PMID: 24161681 DOI: 10.1016/j.jmr.2013.09.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 09/24/2013] [Accepted: 09/26/2013] [Indexed: 06/02/2023]
Abstract
Cryogenic probes have significantly increased the sensitivity of NMR. Here, we present a compact EPR receiver design capable of cryogenic operation. Compared to room temperature operation, it reduces the noise by a factor of ≈2.5. We discuss in detail the design and analyze the resulting noise performance. At low microwave power, the input noise density closely follows the emission of a cooled 50Ω resistor over the whole measurement range from 20K up to room temperature. To minimize the influence of the microwave source noise, we use high microwave efficiency (≈1.1-1.7mTW(-1/2)) planar microresonators. Their efficient conversion of microwave power to magnetic field permits EPR measurements with very low power levels, typically ranging from a few μW down to fractions of nW.
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Affiliation(s)
- R Narkowicz
- Department of Physics, TU Dortmund University, Otto-Hahn-Str. 4, D-44221 Dortmund, Germany.
| | - H Ogata
- Max-Planck Institute for Chemical Energy Conversion, Stiftsraße 34-36, D-45470 Mülheim a.d. Ruhr, Germany
| | - E Reijerse
- Max-Planck Institute for Chemical Energy Conversion, Stiftsraße 34-36, D-45470 Mülheim a.d. Ruhr, Germany
| | - D Suter
- Department of Physics, TU Dortmund University, Otto-Hahn-Str. 4, D-44221 Dortmund, Germany
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Mentink-Vigier F, Collauto A, Feintuch A, Kaminker I, Tarle V, Goldfarb D. Increasing sensitivity of pulse EPR experiments using echo train detection schemes. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 236:117-125. [PMID: 24121563 DOI: 10.1016/j.jmr.2013.08.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 08/25/2013] [Accepted: 08/26/2013] [Indexed: 06/02/2023]
Abstract
Modern pulse EPR experiments are routinely used to study the structural features of paramagnetic centers. They are usually performed at low temperatures, where relaxation times are long and polarization is high, to achieve a sufficient Signal/Noise Ratio (SNR). However, when working with samples whose amount and/or concentration are limited, sensitivity becomes an issue and therefore measurements may require a significant accumulation time, up to 12h or more. As the detection scheme of practically all pulse EPR sequences is based on the integration of a spin echo--either primary, stimulated or refocused--a considerable increase in SNR can be obtained by replacing the single echo detection scheme by a train of echoes. All these echoes, generated by Carr-Purcell type sequences, are integrated and summed together to improve the SNR. This scheme is commonly used in NMR and here we demonstrate its applicability to a number of frequently used pulse EPR experiments: Echo-Detected EPR, Davies and Mims ENDOR (Electron-Nuclear Double Resonance), DEER (Electron-Electron Double Resonance|) and EDNMR (Electron-Electron Double Resonance (ELDOR)-Detected NMR), which were combined with a Carr-Purcell-Meiboom-Gill (CPMG) type detection scheme at W-band. By collecting the transient signal and integrating a number of refocused echoes, this detection scheme yielded a 1.6-5 folds SNR improvement, depending on the paramagnetic center and the pulse sequence applied. This improvement is achieved while keeping the experimental time constant and it does not introduce signal distortion.
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Affiliation(s)
- F Mentink-Vigier
- Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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15
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Yap YS, Yamamoto H, Tabuchi Y, Negoro M, Kagawa A, Kitagawa M. Strongly driven electron spins using a K(u) band stripline electron paramagnetic resonance resonator. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 232:62-67. [PMID: 23703225 DOI: 10.1016/j.jmr.2013.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/23/2013] [Accepted: 04/26/2013] [Indexed: 06/02/2023]
Abstract
This article details our work to obtain strong excitation for electron paramagnetic resonance (EPR) experiments by improving the resonator's efficiency. The advantages and application of strong excitation are discussed. Two 17 GHz transmission-type, stripline resonators were designed, simulated and fabricated. Scattering parameter measurements were carried out and quality factor were measured to be around 160 and 85. Simulation results of the microwave's magnetic field distribution are also presented. To determine the excitation field at the sample, nutation experiments were carried out and power dependence were measured using two organic samples at room temperature. The highest recorded Rabi frequency was rated at 210 MHz with an input power of about 1 W, which corresponds to a π/2 pulse of about 1.2 ns.
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Affiliation(s)
- Yung Szen Yap
- Graduate School of Engineering Science, Osaka University, Japan.
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16
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Malissa H, Schuster DI, Tyryshkin AM, Houck AA, Lyon SA. Superconducting coplanar waveguide resonators for low temperature pulsed electron spin resonance spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:025116. [PMID: 23464260 DOI: 10.1063/1.4792205] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We discuss the design and implementation of thin film superconducting coplanar waveguide micro-resonators for pulsed electron spin resonance experiments. The performance of the resonators with P doped Si epilayer samples is compared to waveguide resonators under equivalent conditions. The high achievable filling factor even for small sized samples and the relatively high Q-factor result in a sensitivity of 4.5 × 10(8) spins per shot, which is superior to that of conventional waveguide resonators, in particular to spins close to the sample surface. The peak microwave power is on the order of a few milliwatts, which is compatible with measurements at ultra-low temperatures. We also discuss the effect of the nonuniform microwave magnetic field on the Hahn echo power dependence.
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Affiliation(s)
- H Malissa
- Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544, USA
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17
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Twig Y, Dikarov E, Blank A. Ultra miniature resonators for electron spin resonance: Sensitivity analysis, design and construction methods, and potential applications. Mol Phys 2013. [DOI: 10.1080/00268976.2012.762463] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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18
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Borneman TW, Cory DG. Bandwidth-limited control and ringdown suppression in high-Q resonators. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 225:120-9. [PMID: 23165232 DOI: 10.1016/j.jmr.2012.10.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 10/18/2012] [Accepted: 10/21/2012] [Indexed: 05/12/2023]
Abstract
We describe how the transient behavior of a tuned and matched resonator circuit and a ringdown suppression pulse may be integrated into an optimal control theory (OCT) pulse-design algorithm to derive control sequences with limited ringdown that perform a desired quantum operation in the presence of resonator distortions of the ideal waveform. Inclusion of ringdown suppression in numerical pulse optimizations significantly reduces spectrometer deadtime when using high quality factor (high-Q) resonators, leading to increased signal-to-noise ratio (SNR) and sensitivity of inductive measurements. To demonstrate the method, we experimentally measure the free-induction decay of an inhomogeneously broadened solid-state free radical spin system at high Q. The measurement is enabled by using a numerically optimized bandwidth-limited OCT pulse, including ringdown suppression, robust to variations in static and microwave field strengths. We also discuss the applications of pulse design in high-Q resonators to universal control of anisotropic-hyperfine coupled electron-nuclear spin systems via electron-only modulation even when the bandwidth of the resonator is significantly smaller than the hyperfine coupling strength. These results demonstrate how limitations imposed by linear response theory may be vastly exceeded when using a sufficiently accurate system model to optimize pulses of high complexity.
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Affiliation(s)
- Troy W Borneman
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
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19
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Twig Y, Dikarov E, Blank A. Cryogenic electron spin resonance microimaging probe. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 218:22-29. [PMID: 22578551 DOI: 10.1016/j.jmr.2012.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 02/09/2012] [Accepted: 03/13/2012] [Indexed: 05/31/2023]
Abstract
A new probe for acquiring ESR images with microscopic resolution and high spin sensitivity, at a temperature range of ~4.2-300 K, is presented. Details of the probe design, as well as its principle of operation, are provided. The probe incorporates a unique surface loop-gap microresonator. Experimental results demonstrate the system's capability to acquire two - as well as three-dimensional images with a flat test sample of phosphorus-doped silicon. The imaging results also allow verifying the resonator's resonance mode - they show its B(1) distribution, which also makes it possible to estimate the number of spins measured in the sample.
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Affiliation(s)
- Ygal Twig
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
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Anders J, Angerhofer A, Boero G. K-band single-chip electron spin resonance detector. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 217:19-26. [PMID: 22405529 DOI: 10.1016/j.jmr.2012.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/06/2012] [Accepted: 02/07/2012] [Indexed: 05/31/2023]
Abstract
We report on the design, fabrication, and characterization of an integrated detector for electron spin resonance spectroscopy operating at 27 GHz. The microsystem, consisting of an LC-oscillator and a frequency division module, is integrated onto a single silicon chip using a conventional complementary metal-oxide-semiconductor technology. The achieved room temperature spin sensitivity is about 10(8)spins/G Hz(1/2), with a sensitive volume of about (100 μm)(3). Operation at 77K is also demonstrated.
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Affiliation(s)
- Jens Anders
- Ecole Polytechninque Federale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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