Movatterモバイル変換

[0]ホーム
URL:

Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
Thehttps:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

NIH NLM Logo
Log inShow account info
Access keysNCBI HomepageMyNCBI HomepageMain ContentMain Navigation
pubmed logo
Advanced Clipboard
User Guide

Full text links

Atypon full text link Atypon Free PMC article
Full text links

Actions

Share

.2014 Aug 19;111(33):11955-60.
doi: 10.1073/pnas.1402015111. Epub 2014 Aug 4.

Scalable NMR spectroscopy with semiconductor chips

Affiliations

Scalable NMR spectroscopy with semiconductor chips

Dongwan Ha et al. Proc Natl Acad Sci U S A..

Abstract

State-of-the-art NMR spectrometers using superconducting magnets have enabled, with their ultrafine spectral resolution, the determination of the structure of large molecules such as proteins, which is one of the most profound applications of modern NMR spectroscopy. Many chemical and biotechnological applications, however, involve only small-to-medium size molecules, for which the ultrafine resolution of the bulky, expensive, and high-maintenance NMR spectrometers is not required. For these applications, there is a critical need for portable, affordable, and low-maintenance NMR spectrometers to enable in-field, on-demand, or online applications (e.g., quality control, chemical reaction monitoring) and co-use of NMR with other analytical methods (e.g., chromatography, electrophoresis). As a critical step toward NMR spectrometer miniaturization, small permanent magnets with high field homogeneity have been developed. In contrast, NMR spectrometer electronics capable of modern multidimensional spectroscopy have thus far remained bulky. Complementing the magnet miniaturization, here we integrate the NMR spectrometer electronics into 4-mm(2) silicon chips. Furthermore, we perform various multidimensional NMR spectroscopies by operating these spectrometer electronics chips together with a compact permanent magnet. This combination of the spectrometer-electronics-on-a-chip with a permanent magnet represents a useful step toward miniaturization of the overall NMR spectrometer into a portable platform.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
NMR spectrometer combining silicon spectrometer electronics chips and a 0.51-T NdFeB permanent magnet (W × D × H: 12.6 × 11.7 × 11.9 cm3; weight: 7.3 kg; Neomax Co.).
Fig. 2.
Fig. 2.
Spectrometer electronics chip architecture and measurements. (A) Free-induction decay (FID) experiments with ethylbenzene demonstrate multiphase generation; 32 FID signals excited by π/2 pulses with 32 different RF phases (Upper) are aligned (Lower), after shifting each signal by its respective excitation phase. These particular experiments were done before the magnet shimming. (B) Receiver input referred noise; and (C) receiver gain.
Fig. 3.
Fig. 3.
One-dimensional1H NMR spectroscopy. (A) Setup. (B–H) The 1D spectra for deionized tap water (1 scan), ethanol (1 scan),l-alanine (64 scans), ethylbenzene (1 scan), aspirin (64 scans),l-serine (64 scans), andd-(+)-glucose (64 scans).l-alanine,l-serine, andd-(+)-glucose are dissolved in D2O (1.5 M). Aspirin is dissolved in DMSO-d6 (1.5 M).
Fig. 4.
Fig. 4.
Two-dimensional1H NMR spectroscopy. (A) Setup; 1D spectra of ethanol andl-alanine, identical to Fig. 3C andD. (B)J-resolved spectra of ethanol (Left) andl-alanine (Right); each takes 15 min to obtain (84 scans with a single scan/wait time of 11 s). In the pulse sequence, black (white) bar signifies a π/2 (π) pulse. Quadrature detection in thef1 domain is done by additional phase cycle with ϕ1 shifted by π/2 (41). (C) COSY spectra of ethanol (Left) andl-alanine (Right); each takes 73 min to acquire (400 scans with a single scan/wait time of 11 s).
Fig. 5.
Fig. 5.
Two-dimensional heteronuclear spectroscopy with methanol. (A) Setup. (B)1H-only 1D spectrum. (C) HSQC spectrum. A four-phase cycling to select the particular coherence pathway uses ϕ1∈{0,π,0,π}, ϕ2∈{0,0,π,π}, and ϕ3∈{0,π,π,0}. HSQC spectrum takes 17 min to obtain (168 scans including phase cycling with a single scan/wait time of 6 s). (D) HMQC spectrum. An eight-phase cycling to select the particular coherence pathway uses ϕ1∈{0,π,0,π,0,π,0,π}, ϕ2∈{0,0,π/2, π/2,π,π,3π/2,3π/2}, and ϕ3∈{0,π,π,0,0,π,π,0}. HMQC spectrum takes 34 min to acquire (336 scans including phase cycling with a single scan/wait time of 6 s). ForC andD, the13C π/2-pulse duration is obtained separately (Materials and Methods), and τ = 1/(4JC-H).
Fig. 6.
Fig. 6.
Raw,f2-calibrated, andf2- andf1-calibrated COSY ethanol spectrum; the final one is identical to Fig. 4C,Left.
Fig. 7.
Fig. 7.
1H NMR relaxometry for a crude oil sample. (A) Setup. (B) CPMG echo signal vs. echo time at 25 °C (blue) and 150 °C (red). (C,Left) Semilog plot of the echo decay at 25 °C (blue) and 150 °C (red). Echo spacing is 4 ms. (Right)T2 spectrum at 25 °C.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Aue WP, Bartholdi E, Ernst RR. Two–dimensional spectroscopy. Application to nuclear magnetic resonance. J Chem Phys. 1976;64(5):2229–2246.
    1. Bajaj VS, Paulsen J, Harel E, Pines A. Zooming in on microscopic flow by remotely detected MRI. Science. 2010;330(6007):1078–1081. - PubMed
    1. Pellecchia M, Sem DS, Wüthrich K. NMR in drug discovery. Nat Rev Drug Discov. 2002;1(3):211–219. - PubMed
    1. Wensink H, et al. Measuring reaction kinetics in a lab-on-a-chip by microcoil NMR. Lab Chip. 2005;5(3):280–284. - PubMed
    1. Wüthrich K. NMR studies of structure and function of biological macromolecules (Nobel lecture) Angew Chem Int Ed Engl. 2003;42(29):3340–3363. - PubMed

Publication types

MeSH terms

LinkOut - more resources

Full text links
Atypon full text link Atypon Free PMC article
Cite
Send To

NCBI Literature Resources

MeSHPMCBookshelfDisclaimer

The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Unauthorized use of these marks is strictly prohibited.

[8]ページ先頭
©2009-2025 Movatter.jp