EPR Spectroscopy Equipment

This technique enables identification of radicals in a sample using CW EPR spectroscopy and, spatial localisation of suitable spin probes or paramagnetic centres. Spatial resolution depends upon the spin probe, for narrow line radicals the resolution is around 500 μm. Example applications include the study of paramagnetic centres in materials such as polymers and in vivo imaging of small animals using introduced spin probes to measure for example oxygen concentration or spin traps to detect reactive oxygen species. 

• Imaging at X-band offers high quality sensitivity and resolution for materials such as polymers, powders, or nonpolar solutions at room temperature. For aqueous samples, e.g. cells or sections, measurement in flat cells and imaging in 2D is possible
• Imaging at L-band enables in vivo imaging of small objects up to the size of a mouse (active volume of 30 mm3)

Bruker Elexsys E580 Pulsed Q-band (33GHz) and X-band (9.6 GHz) Spectrometer with high power microwave amplifiers for EPR, ENDOR, ESEEM, DEER and ELDOR experiments in the temperature range 1.7-300 K

• Optical windows allow for sample illumination 
• Field-sweep EPR in both continuous wave (CW) and pulse mode over the field range 0-1.4 T
• Electron nuclear double resonance (ENDOR) at both X-band and Q-band in the frequency range 0.1 – 200 MHz for measuring electron-nuclear couplings to magnetic nuclei including 1 H, 13C, 14N, 15N, 17O, 19F, 31P, 57Fe 
• Electron spin echo envelope modulation (ESEEM) experiments such as three-pulse ESEEM and HYSCORE, for measuring electron-nuclear couplings with high sensitivity at both X-band and Q-band due to the availability of high power traveling wave tube amplifiers 
• Double electron electron resonance (DEER) or pulse electron double resonance (PELDOR) for the measurement of electron-electron distances in the range ca. 15-100 Å, typically for research on large biomolecules or polymers containing two or more spin labels. Sensitivity at Q-band is <20 µM with a sample size <10 µL. The spectrometer is suitable for paramagnetic spin labels based on organic radicals like the commonly used MTSSL or metal tags like ones based on Gd(III) ions. DEER at X-band in resonators accommodating either 2 mm, 3 mm, or 3.8 mm sample tubes offers a range of excitation bandwidths and sensitivities for experiments using organic spin labels or suitable centres intrinsic to the material under investigation 
• ELDOR – electron double resonance capabilities employing two microwave sources. For example, ELDOR detected NMR for measuring electron-nuclear couplings