Large NMR Enhancements for Aqueous Samples
Related Product: X-Band Microwave Source for ODNP
Overhauser DNP Spectroscopy
Overhauser Dynamic Nuclear Polarization (ODNP) enhanced NMR spectroscopy at 9 GHz (0.35 T, 15 MHz 1H NMR frequency) is a powerful method for site-specific studies of the accessibility and translational dynamics of water molecules at or near bio-macromolecules, membrane proteins, or other interfaces such as polymer/solvent interfaces [1, 2]. Although the method has been around since the 1960s, it has just recently been successfully applied in structural biology and material science. The unique instrumentation requirements had previously limited the application of ODNP-enhanced NMR spectroscopy, specifically the lack of commercially available microwave sources and DNP probes that are compatible with existing EPR instrumentation.
Upgrade your existing EPR Spectrometer
Unlike high-field DNP-enhanced solid- state NMR experiments ODNP experiments 9 GHz do not require a large superconducting NMR magnet or a high-power/high-frequency microwave source such as a gyrotron. In fact, any home-built or commercially available X-band EPR spectrometer, instruments that can be found in many academic research institutes, can be easily upgraded with Bridge12 products to do ODNP specroscopy.
A turn-key ODNP probe for your research
The Bridge12 ODNP probe can be easily installed in a conventional X-band EPR cavity (e.g. Bruker 4102ST or Varian E231) and it comes with all necessary adapter parts to mount the probe. The positions of the NMR coil wires are optimized and the Q of the EPR cavity is only minimally affected. This conserves the high conversion factor of the EPR probe and minimizes sample heating even when using very high microwave power.
Change the sample, not the probe
The Bridge12 ODNP probe has a simple and convenient system to change the sample. Once the probe is mounted inside the EPR cavity and its position is optimized the probe will stay inside the EPR cavity and the probe does not have to be removed to change the sample. The sample can be loaded either into a quartz sample tube (2 mm OD, 1 mm ID) or into a small sample capillary (0.84 mm OD, 0.6 mm ID). The probe comes with sample holders for both options.
1H ODNP enhancements of 4-amino TEMPO in WaterObserve 1H or 19F or any nucleus you desire
The Bridge12 ODNP probe is a single channel NMR probe. Depending on your application the probe can be tuned to observe 1H, 19F, 2H, 13C or any other nucleus you are interested in.
1H ODNP Enhancement Profile
All RF tuning elements are conveniently located at the front of the probe. That makes it very easy to tune the probe to a new frequency and for example DNP enhancement profiles are recorded in a very short amount of time.
- Technical Specifications Operating NMR Frequency: 14.5 +/- 0.5 MHz (other frequencies available)
- Sample Size: Probe works very well with 2 mm sample tubes (Wilmad 712-SQ-250 mm or 0.84 mm capillaries (e.g. VitroCom CV6084-Q).
- Maximum sample diameter 2.5 mm. Probes for larger sample sizes (non aqueous) are available.
- Sample holder and probe mounts included.
- Probe requires EPR cavity, e.g. Bruker 4102ST (TE102), 4119HS, 4122HSQE or ER4123D (TE011-like), or Varian E231 (TE102) for X-Band operation (Other frequencies available)
- Unloaded resonator Q with probe installed: > 3100 For optimum performance probe requires flow of clean, dry air (> 5 lpm)
 Franck, J.M., et al., Quantitative cw Overhauser Effect Dynamic Nuclear Polarization for The Analysis of Local Water Dynamics, Prog. Nucl. Magn. Reson. Spectrosc., 2013, 74(0), p. 33-56.
 Kaminker, I., Barnes, R., Han, Songi, Overhauser Dynamic Nuclear Polarization Studies on Local Water Dynamics, Meth. Enzym., 2015, 564, p. 457-483.