Microscale resonator and shimming system for microfluidic-based nuclear magnetic resonance spectroscopy

Datum

06.02.2025

Zeit

11:10 - 12:10

Sprecher

Alaleh Mirhajivarzaneh

Zugehörigkeit

IFW Dresden

Sprache

en

Hauptthema

Materialien

Host

Beschreibung

Over the past few decades, efforts to miniaturize Nuclear Magnetic Resonance (NMR) spectroscopy have resulted in the down-scaling of the core of the NMR system to microscale detectors or resonators. This achievement has unfolded a new era of NMR spectroscopy, with applications in biological and chemical analysis, where the sample size can scale down to micro- or nanoliters, typical of microorganisms and cell cultures. This thesis presents a comprehensive study on optimizing the performance of a previously developed microresonator, specifically the self-assembled rolled-up microcoil, for NMR spectroscopy. The optimization process involved the improvement of the sensitivity, notably achieving a 37.3% increase in SNR for samples with a resistance of 2.8 D. Moreover, a new microfluidic system was developed to replace the previous PDMS-based system, which introduced parasitic effects in the NMR measurements. A crucial advantage of this novel system is its adaptability to different resin-based materials, resulting in a more efficient and versatile device. Furthermore, the microcoil was used for the analysis of two biological analytes; oocyte media and blood plasma. This investigation provided valuable insights into the practical limits of detection for this technology and helped to identify prospective directions for future research and applications. Magnetic shimming is a widely used technique for homogenizing NMR magnetic fields. However, the benefits of miniaturizing these systems can be substantial, particularly in addressing the inhomogeneities encountered in experiments with microresonators. Additionally, miniaturization contributes to reducing both size and cost. A significant innovation introduced in this work is the design and implementation of a microscale shimming system for the first time tailored to the specification of the 3D microcoil. This magnetic shimming system, developed using similar fabrication techniques to the microcoil, achieved a 15% reduction in the average linewidth compared to the control experiments using shimming coils with no current applied. This achievement opens up new possibilities for further exploration and optimization, potentially broadening the scope of applications and enhancing the performance of microscale NMR coils.

Links

• Seminars at the IFW

Letztmalig verändert: 05.02.2025, 07:37:07