Optical hyperpolarization and NMR detection of Xe-129 on a microfluidic chip

Optically hyperpolarized Xe-129 gas has become a powerful contrast agent in nuclear magnetic resonance (NMR) spectroscopy and imaging, with applications ranging from studies of the human lung to the targeted detection of biomolecules. Equally attractive is its potential use to enhance the sensitivity of microfluidic NMR experiments, in which small sample volumes yield poor sensitivity. Unfortunately, most Xe-129 polarization systems are large and non-portable. Here we present a microfabricated chip that optically polarizes Xe-129 gas. We have achieved Xe-129 polarizations >0.5% at flow rates of several microlitres per second, compatible with typical microfluidic applications. We employ in situ optical magnetometry to sensitively detect and characterize the Xe-129 polarization at magnetic fields of 1 mu T. We construct the device using standard microfabrication techniques, which will facilitate its integration with existing microfluidic platforms. This device may enable the implementation of highly sensitive Xe-129 NMR in compact, low-cost, portable devices.