Available Technology

DETECTION OF J-COUPLING USING ATOMIC MAGNETOMETER

Zero- to ultralow-field nuclear magnetic resonance (ZULF NMR) spectroscopy has emerged as a new, potentially portable and cost-effective NMR modality to determine the molecular structure and properties of microfluidic chemical samples, using chemical signatures known as J-couplings or scalar coupling. Conventional NMR spectrometers are large and utilize superconducting magnets operating at liquid helium temperatures. This precludes their use in many situations where NMR would be beneficial. Benchtop NMR spectrometers are currently available operating in the 60 MHz range . However, they often lack the desired sensitivity. To develop a portable ZULF NMR spectrometer with improved sensitivity, a number of challenges must be addressed.  The approach that holds great promise is to develop an atomic magnetometer  that will  have the desired level of sensitivity in a low (Earth’s field) or near-zero magnetic field. This approach eliminates the need for cryogenic cooling and provides high sensitivity to samples of microliter volumes. It is anticipated that this invention may provide a new modality for high precision ‘J spectroscopy’ using small samples on microchip devices for multiplexed screening, assaying and sample identification in chemistry and biomedicine. It can be used widely in both pure research environments and industry.  Additonally, this invention can be used for pharmaceutical drug discovery, chemical production, security monitoring applications, drug design, catalyst evaluation and optimization, pharmaceutical and biomedical research tools, portable NMR detectors, and the detection of liquid explosives. Potential partners include instrument manufacturers of NMR detectors used in the pharmaceutical,  biomedical and other industries for drug design, catalyst evaluation and liquid explosive detection. 

The figure below (100) illustrates a system for detecting J-coupling.  The components of the system are: optical atomic magnetometer, a fluid handling system (101), syringe pump (102), reservoir (104), polarization volume (106), Halbach array (108), detection volume (110), alkali vapor cell (112), magnetic shields (114), exterbak-cavity diode laser (116), photodiode (118), set of coils (120), oven (122), solenoid (124), pressurized reservoir (126), linear polarizers (128), quarter wave plate (130), lock-in amplifier (132), data acquisition system (134), and a spectrum analyzer (136).

 

 


 

Abstract: 

An embodiment of a method of detecting a J-coupling of the present invention includes providing a polarized analyte adjacent to a vapor cell of an atomic magnetometer and measuring one or more J-coupling parameters using the atomic magnetometer. According to an embodiment, measuring one or more J-coupling parameters includes detecting a magnetic field created by the polarized analyte as the magnetic field evolves under a J-coupling interaction.

Benefits: 

This approach does not require superconducting magnets or cryogenics to enable high resolution two-dimensional spectroscopy. The technology utilizes an atomic magnetometer instead of RF coils to directly sense a polarized sample’s magnetic field and provides the desired sensitivity with small sample assays.

Inventors: 
David Wemmer, Charles Crawford, John Kitching, Dmitry Budker, Alex Pines, Svenja Knappe, Micah Ledbetter
Patent Number: 
9,140,657
Technology Type(s): 
Homeland Security, Optical Technology, Advanced Manufacturing Processes, Analytical Chemistry, Health Care, Atomic Spectroscopy, Biochemical Science, Chemical Sciences, Electromagnetics, Physical and Chemical Properties, Precision Measurement,
Internal Laboratory Ref #: 
12-018
Patent Issue Date: 
September 22, 2015
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