title: Nuclear magnetic resonance detection and spectroscopy of single proteins using quantum logic.
abstract: Nuclear magnetic resonance spectroscopy is a powerful tool for the structural analysis of organic compounds and biomolecules but typically requires macroscopic sample quantities. We use a sensor, which consists of two quantum bits corresponding to an electronic spin and an ancillary nuclear spin, to demonstrate room temperature magnetic resonance detection and spectroscopy of multiple nuclear species within individual ubiquitin proteins attached to the diamond surface. Using quantum logic to improve readout fidelity and a surface-treatment technique to extend the spin coherence time of shallow nitrogen-vacancy centers, we demonstrate magnetic field sensitivity sufficient to detect individual proton spins within 1 second of integration. This gain in sensitivity enables high-confidence detection of individual proteins and allows us to observe spectral features that reveal information about their chemical composition.
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA.
authors: I
authors: I
authors: Lovchinsky
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA. Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
authors: A O
authors: AO
authors: Sushkov
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA.
authors: E
authors: E
authors: Urbach
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA. Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
authors: N P
authors: NP
authors: de Leon
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA.
authors: S
authors: S
authors: Choi
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA.
authors: K
authors: K
authors: De Greve
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA.
authors: R
authors: R
authors: Evans
authors: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
authors: R
authors: R
authors: Gertner
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA.
authors: E
authors: E
authors: Bersin
authors: Institute for Quantum Optics and Center for Integrated Quantum Science and Technology (IQST), Ulm University, D-89081, Ulm, Germany.
authors: C
authors: C
authors: Müller
authors: Institute for Quantum Optics and Center for Integrated Quantum Science and Technology (IQST), Ulm University, D-89081, Ulm, Germany.
authors: L
authors: L
authors: McGuinness
authors: Institute for Quantum Optics and Center for Integrated Quantum Science and Technology (IQST), Ulm University, D-89081, Ulm, Germany.
authors: F
authors: F
authors: Jelezko
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA. Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.
authors: R L
authors: RL
authors: Walsworth
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA. Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA. Center for Brain Science, Harvard University, Cambridge, MA 02138, USA. Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA. lukin@physics.harvard.edu hongkun_park@harvard.edu.
authors: H
authors: H
authors: Park
authors: Department of Physics, Harvard University, Cambridge, MA 02138, USA. lukin@physics.harvard.edu hongkun_park@harvard.edu.
authors: M D
authors: MD
authors: Lukin
mesh_terms: D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000032:analysis*; D011789:Quantum Theory; D012680:Sensitivity and Specificity
chemical_list: D011506:Proteins