Session ThOF. There are 4 abstracts in this session.

Session: INSTRUMENTATION 2, time: 4:00 - 4:25 pm

Environmental In-vivo NMR: Experiments, Instrumentation and the Introduction of Something a Little Special!

Andre J Simpson
University of Toronto, Toronto, Canada

In in-vivo NMR the living organism becomes the “ultimate biosensor” responding in real time to its environment, while the NMR spectrometer interprets the biochemical changes, providing information explaining sub-lethal toxicity at the molecular level. This presentation will walk through the development on environmental in-vivo NMR at the Environmental NMR Center (University of Toronto), with a focus on the challenges and breakthroughs to overcome them. Examples include, isotopic enriched nD NMR, removal of susceptibility broadening, targeted 2D NMR, micro-coil NMR of tiny eggs and digital microfluidic NMR for sample handling. Finally, the presentation will introduce a novel technique, ahead of publication, that should represent a paradigm shift in the application of NMR to ultra-complex mixtures, including intact biofluids and living organisms.

Session: INSTRUMENTATION 2, time: 4:25 - 4:40 pm

Progress of the Cosmic Axion Spin Precession Experiment (CASPEr)

John Blanchard
Helmholtz-Institut Mainz, Mainz, Germany

The nature of dark matter, the invisible substance that makes up over 80% of the matter in the universe, is one of the most intriguing mysteries of modern physics. The Cosmic Axion Spin Precession Experiment (CASPEr) is a multi-faceted research program using NMR techniques to search for dark-matter-driven spin-precession.

I will discuss our recent results using zero- to ultralow-field (ZULF) NMR and efforts to use parahydrogen-enhanced spin polarization to enhance CASPEr-ZULF sensitivity. I will also report on commissioning of and preliminary results from the low-field (10-4 – 10-1 Tesla) experiments. In this field range, we are using superconducting quantum interference devices (SQUIDs) to measure a liquid 129Xe target polarized via spin-exchange optical pumping (SEOP).

Session: INSTRUMENTATION 2, time: 4:40 - 4:55 pm

A first NMR study of 3D micro-liver models at nL scale 

Marco Grisi1, 2; Gaurasundar Conley1, 2; Erika Riva3; Kyle Rodriguez4; Lukas Egli5; Jürgen Brugger2; Giovanni Boero2
1Annaida Technologies SA, Lausanne, Switzerland; 2Microsystems Laboratory, EPFL, Lausanne, Switzerland; 3Service de gastroentérologie et d’hépatogie, CHUV, Epalinges, Switzerland; 4Adolphe Merkle Institute, Fribourg, Switzerland; 5InSpheroAG, Schlieren, Switzerland

In this work we describe an NMR micro-system consisting of a ultra-compact CMOS probe combined with a microscale 3D printed holder tailored for biological samples having volumes of about 7 nL (i.e., diameters of about 240 μm). With this device we performed spectroscopy of models of 3D micro-livers grown from human cell lines. With a sensing region of about 2 nL and a spin sensitivity of 2.5·1013 spins/Hz1/2, we were able to distinguish steatotic from lean micro-livers with 1D 1H spectra obtained in 10 minutes at a field strength of 7 T. Such an achievement is made possible by a micro-NMR device that is robust, highly sensitive, and easy to use. 

Session: INSTRUMENTATION 2, time: 4:55 - 5:10 pm

Sorption measurements of vapors inside microporous materials by a NMR-physisorption bi-modal instrumentation and time-resolved relaxometry

Rodrigo Oliveira-Silva; Joao Marreiros; Rob Ameloot; Dimitrios Sakellariou
KU Leuven, Leuven, Belgium

Low-field NMR relaxometry (LFNMR) is applied commonly to porous media analysis to measure directly the content and physicochemical properties of the porous environment through nuclear spin relaxation of the contained liquid. Materials such as metal-organic frameworks (MOFs), mesoporous silicas, and zeolites are typically characterized using gas/vapor adsorption and desorption isotherms. We present a first account of simultaneous online physisorption and LFNMR for the study of microporous MOFs, with vapors of organic molecules. A custom-made permanent magnet was designed and integrated with a commercial physisorption analyzer, without interference. Results show the complementarity of LFNMR to the sorption isotherms by the T1 and T2 relaxation time distributions, which scope the nature and specificity of the interactions between different guest molecules and adsorbents.