A Microfluidic High-Resolution NMR Flow Probe

Bart, Jacob; Kolkman, A.J.; Vries, A.J. Oosthoek-de; Koch, Karl‐Heinz; Nieuwland, Pieter J.; Janssen, Hans; Bentum, Jan P J M van; Ampt, K.A.M.; Rutjes, Floris P. J. T.; Wijmenga, Sybren S.; Gardeniers, Han; Kentgens, A.P.M.

doi:10.1021/ja900389x

Cited by 138 publications

(108 citation statements)

References 13 publications

Supporting

Mentioning

104

Contrasting

Unclassified

Order By: Relevance

“…Van Bentum et al [15,16] have demonstrated the excellent sensitivity and both high B 0 and B 1 homogeneity o ered by planar transmission line resonators. These designs are characterised by a planar conductor which is aligned with the static magnetic field symmetrically in between two ground planes.…”

Section: Introductionmentioning

confidence: 99%

An optimised detector for in-situ high-resolution NMR in microfluidic devices

Finch

Yılmaz

Utz

2016

Journal of Magnetic Resonance

109

View full text Add to dashboard Cite

Integration of high-resolution nuclear magnetic resonance (NMR) spectroscopy with microfluidic lab-on-a-chip devices is challenging due to limited sensitivity and line broadening caused by magnetic susceptibility inhomogeneities. We present a novel double-stripline NMR probe head that accommodates planar microfluidic devices, and obtains the NMR spectrum from a rectangular sample chamber on the chip with a volume of 2 l. Finite element analysis is used to jointly optimise the detector and sample volume geometry for sensitivity and RF homogeneity. A prototype of the optimised design has been built, and its properties have been characterised experimentally. The performance in terms of sensitivity and RF homogeneity closely agrees with the numerical predictions. The system reaches a mass limit of detection of 1.57 nMol p s, comparing very favourably with other micro-NMR systems. The spectral resolution of this chipGprobe system is better than 1.75 Hz at a magnetic field of 7 T, with excellent line shape.

show abstract

Section: Introductionmentioning

confidence: 99%

An optimised detector for in-situ high-resolution NMR in microfluidic devices

Finch

Yılmaz

Utz

2016

Journal of Magnetic Resonance

109

View full text Add to dashboard Cite

show abstract

“…These probe structures can themselves cause susceptibility broadening. However, the demagnetising fields generated can be minimised by choosing planar geometries aligned with the magnetic field such as micro-stripline probes [13][14][15][16] . In general, the thickness of metallic detection structures can be reduced down to a few times the skin depth, which is of the order of a few µm for copper at typical NMR frequencies.…”

Section: Resultsmentioning

confidence: 99%

“…Micro-fabricated receiver structures can be directly integrated into lab-on-achip devices, and systems with limits of detection as low as 0.025 nmol · s 1/2 have been reported in the literature 5 . Different detector geometries and microfabrication strategies for microfluidic NMR have been described, including solenoids [6][7][8] , planar spirals [9][10][11][12] , and microslots/micro striplines [13][14][15][16] . While these approaches yield similar sensitivity for a given probe volume, resolution in the vicinity of 0.01 ppm has only been achieved with very simple, linear fluidic geometries (capillar- ies).…”

Section: Introductionmentioning

confidence: 99%

Structural shimming for high-resolution nuclear magnetic resonance spectroscopy in lab-on-a-chip devices

2014

View full text Add to dashboard Cite

High-resolution proton NMR spectroscopy is well-established as a tool for metabolomic analysis of biological fluids at the macro scale. Its full potential has, however, not been realised yet in the context of microfluidic devices. While microfabricated NMR detectors offer substantial gains in sensitivity, limited spectral resolution resulting from mismatches in the magnetic susceptibility of the sample fluid and the chip material remains a major hurdle. In this contribution, we show that susceptibility broadening can be compensated even in the presence of substantial mismatch by including suitably shaped compensation structures into the chip design. An efficient algorithm for the calculation of field maps from arbitrary chip layouts based on Gaussian quadrature is used to optimise the shape of the compensation structure to ensure a flat field distribution inside the sample area. Previously, the complexity of microfluidic NMR systems has been restricted to simple capillaries to avoid susceptibility broadening. The structural shimming approach introduced here can be adapted to virtually any shape of sample chamber and surrounding fluidic network, thereby greatly expanding the design space and enabling true lab-on-a-chip systems suitable for high-resolution NMR detection.

show abstract

“…7,72,73 Several different analytical systems were used successfully, such as in-line FT-IR (predominantly with Attenuated Total Reflectance (ATR) cells), [74][75][76][77][78][79][80] NIR, 81,82 Raman 83 and NMR spectroscopy, 84,85 as well as on-line MS 86,87 and HPLC. 88,89 However, everyday application of these approaches is hindered by the fact that off-line solutions are usually more convenient, since a wider toolbox (consisting of existing equipment) is available for the analysis of less demanding analytes (i.e.…”

Section: Possibilities and Limitationsmentioning

confidence: 99%

The route from problem to solution in multistep continuous flow synthesis of pharmaceutical compounds

Bana

Örkényi

Lövei

et al. 2017

Bioorganic & Medicinal Chemistry

View full text Add to dashboard Cite

a b s t r a c tRecent advances in the field of continuous flow chemistry allow the multistep preparation of complex molecules such as APIs (Active Pharmaceutical Ingredients) in a telescoped manner. Numerous examples of laboratory-scale applications are described, which are pointing towards novel manufacturing processes of pharmaceutical compounds, in accordance with recent regulatory, economical and quality guidances. The chemical and technical knowledge gained during these studies is considerable; nevertheless, connecting several individual chemical transformations and the attached analytics and purification holds hidden traps. In this review, we summarize innovative solutions for these challenges, in order to benefit chemists aiming to exploit flow chemistry systems for the synthesis of biologically active molecules.

show abstract

A Microfluidic High-Resolution NMR Flow Probe

Cited by 138 publications

References 13 publications

An optimised detector for in-situ high-resolution NMR in microfluidic devices

An optimised detector for in-situ high-resolution NMR in microfluidic devices

Structural shimming for high-resolution nuclear magnetic resonance spectroscopy in lab-on-a-chip devices

The route from problem to solution in multistep continuous flow synthesis of pharmaceutical compounds

Contact Info

Product

Resources

About