Innovation and Partnerships Office

Detection of J-Couplings at Zero Magnetic Field Using Atomic Magnetometers JIB-2664

APPLICATIONS OF TECHNOLOGY:

  • Drug design
  • Catalyst evaluation and optimization
  • Research tool for pharmaceutical and biomedical industries
  • Portable NMR detectors
  • Detection of liquid explosives

ADVANTAGES:

  • Does not require superconducting magnets or cryogenics
  • Enables high resolution two-dimensional spectroscopy
  • Accurate representation of bonds forming and breaking
  • Superior detection of weak magnetic signals
  • Works in proximity of millimeters to sample

ABSTRACT:

Alexander Pines, Dmitry Budker, Micah Ledbetter, and their colleagues at Berkeley Lab have invented a technology that uses nuclear magnetic resonance (NMR) in a zero magnetic field to determine the molecular structure and properties of microfluidic chemical samples as small as 80 microliters (mL). This is a significant improvement over conventional low-field NMR systems that are limited to sample volumes from 25 to 6,000 times larger.

The Berkeley Lab invention provides unprecedented accuracy in the measurement of chemical signatures known as J-couplings. Conventional low-field NMR techniques cannot measure J-coupling frequencies below 100 mHz; however, the new system makes it possible to detect and encode J-coupling frequencies less than 1 mHz. The invention is also the first to perform low-field NMR analyses of chemical bonds in microfluidic samples without the use of remote detectors. As a result, the Berkeley Lab system can be used as a diagnostic microchip for pharmaceutical and biomedical industries and as a security monitoring or airport screening tool.

This technology uses an atomic magnetometer instead of RF coils to directly sense a polarized sample’s magnetic field and thus accurately read its signal. The invention further prevents signal loss by allowing signal detection and encoding to occur within a single microfabricated device. Optimal sensitivity to small polarized liquid samples is made possible by setting the atomic magnetometer within millimeters of a sample, whereas conventional low-field NMR methods such as superconducting quantum interference devices (SQUID) can be placed only within a centimeter.

Conventional low field NMR is considered ideal for detecting the weak signals of microfluidic samples, but it is not useful for determining dynamic molecular properties such as bond forming and bond breaking–keys to understanding the behavior of a chemical substance. Furthermore, low field NMR methods do not have the ultrasensitivity required to detect the weak, elusive signals characteristic of J-couplings because their RF pickup coils often result in signal loss or distortion.

DEVELOPMENT STAGE:  Proof of principle. Development of a bench-scale prototype is underway.

STATUS: Issued U. S. Patent 9,140,657. Available for licensing or collaborative research.

FOR MORE INFORMATION:

Ledbetter, M.P., C.W. Crawford, A. Pines, D.E. Wemmer, S. Knappe, J. Kitching, “Optical detection of NMR J-spectra at zero magnetic field,” Journal of Magnetic Resonance 199, 1 (2009).

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

Optical Atomic Magnetometer for Portable, Inexpensive MRI and Magnetic Microparticle Detection, IB-2232

Novel Use of NMR with Microfluidic Lab-on-a-Chip Devices, IB-2212

Robust, All-Optical Atomic Magnetometer, IB-2353

REFERENCE NUMBER: JIB-2664