Friday, March 06, 2015

Atomic-Scale Nuclear Spin Imaging Using Quantum-Assisted Sensors in Diamond

Trabajo realizado, por: A. Ajoy, U. Bissbort, M. D. Lukin, R. L. Walsworth, and P. Cappellaro.

Ellos nos dicen:
Las proteínas son la parte más importante como bloques de construcción de la vida. La hablididad de obtener una estructura de proteína de alta resolución es la clave del descubrimiento de drogas (fármacos) desde que la estructura naturalmente revela sitios que pueden ser el objetivo de las drogas. Hay diferentes métodos para determinar la resolución de la estructura de la proteína, tales como cristografía de rayos x, los cuales nos ayudan a comprender más la estructura de una proteína. [...] Recientemente, se ha asociado a los sensores cuánticos con el "nitrogen-vacancy (NV)" en el centro del diamante. (trad. realizada por Mauricio Ortiz).
NV centers in bulk diamond have mapped the location of single 13C nuclear spins inside the diamond crystal [12–14], while shallow-implanted NVs have recently demonstrated the ability to sense a small number of nuclear spins in various organic materials [15–20], as well as single and small ensembles of electronic spins outside the diamond sensor.

Cito sus conclusiones:
We proposed a practical method for atomic-scale nuclear spin imaging in biomolecules using NV centers in diamond. Recent developments in materials fabrication [24,57], ion implantation [58,59], and coherent control techniques [60,61] have brought diamond magnetometers close to the threshold of single nuclear spin sensitivity. These quantum sensors have the potential to be an important tool in proteomics, as they overcome some of the challenges plaguing other experimental techniques, such as x-ray diffraction and conventional NMR. Most prominently, they would not require crystallization of the sample, a challenge for many classes of biomolecules such as membrane proteins, nor large sample sizes. Our novel strategy combines coherent control of the NV sensor with an intrinsic quantum memory to enhance the sensor spectral resolution. This control strategy not only creates a sharp dynamic filter by alternating periods of a spin-lock Hamiltonian with evolution under a gradient field, but it also provides other advantages. The sequence is compatible with homonuclear decoupling, thus allowing sensing beyond the natural biomolecule NMR linewidth. In addition, our technique allows mapping the couplings among the spins themselves, using them as local probes of their environment. The resulting multidimensional NMR spectra highlight spatial correlations in the sample, lift spectral overlaps due to symmetries, and aid the structure reconstruction algorithms. This would allow us to resolve the contributions in the NV signal arising from different nuclear spins in a dense sample and to use the acquired information to determine the nuclear spin positions. Reconstructing a protein local 3D structure under its natural conditions would allow researchers to work backwards and design compounds that interact with specific sites. By combining the strength of NMR-inspired control techniques with the quantum properties of NV center spins, the proposed strategy for magnetic resonance detection at the nanoscale promises to make diamond-based quantum sensors an invaluable technology for bio-imaging.



En mi opinión, es un poco complicado imaginarse los resultados, ya que su trabajo no es algo sencillo. Ellos tuvieron que realizar algunos cálculos, y modificar, de acuerdo a sus necesidades, ciertos métodos para la obtención de sus resultados. Su trabajo ayudará en la industria de la farmacia y, quizás, a los que se dedican a la resonancia magnética, al poder hacer sensores cuánticos de diamantes para las imágenes.

Los invito a leer esta publicación completa, en: https://journals.aps.org/prx/pdf/10.1103/PhysRevX.5.011001


Subida por: Luis Mauricio Ortiz Gálvez.

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The "Silver Song"

Este video es obra creativa de Armando Isaac, para el curso de Química Inorgánica I.