Contact Information Email: Click to Mail Phone: (805) 893-4858 Office Location: 3223 Chemistry Address: Department of Chemistry and Biochemistry 9510 University of California Santa Barbara CA 93106-9510 Chemistry Ph: 805-893-5675 Chemistry Fax: 805-893-4120

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Education & Honors

Honors: Dreyfus New Faculty Award
NSF Career Award

Research

Compared to traditional Nuclear Magnetic Resonance (NMR) where the signal originates from thermal polarization, Dynamic Nuclear Polarization (DNP) enhanced NMR offers a sensitivity gain by up to 4 orders of magnitude. The DNP principle uses highly populated unpaired electron spins, which electron spin resonance (ESR) signal is effectively translated into NMR signal, so that the nucleus of choice (e.g. 1H, 13C, 15N, 31P) in the molecule or material of interest is polarized and prepared for NMR detection. This can bring the detection limit of NMR from the traditional millimolar concentration down to the nanomolar concentration range, and/or allows experiments to be performed with no signal averaging, transforming NMR into a fast and dynamic spectroscopic method. Another approach that the Han group is developing is to employ DNP to provide NMR with unique contrast through polarization transfer from spin labels to the local environment, allowing for the study of large molecular assemblies such as vesicles or lipid bilayer embedded membrane proteins that are difficult to approach by conventional NMR spectroscopy. For the first time, the use of DNP for the "real-time" monitoring of protein aggregation through the site-specific detection of water exclusion as hydrophobic fibrous materials form and enzyme-catalyzed reaction turnover in live bacteria become viable. The Han lab's research objective is the development of a DNP-NMR (0.3-7 Tesla) and pulsed electron spin resonance (9 Tesla) instrument and technique for the application in biochemistry and materials research. The principle of DNP is known, but the approach of its usage is innovative and its application scope new.

• Physical Chemistry, Biophysics

Publications

"Portable X-Band System for Solution State Dynamic Nuclear Polarization", B.D. Armstrong, M.D. Lingwood, E.R. McCarney, E.R. Brown, P. Blmler, S. Han, J. Magn. Reson. (2008), doi: 10.1016/j.jmr.2008.01.004.
"Spin-labeled gel for the production of radical-free dynamic nuclear polarization enhanced molecules for NMR spectroscopy and imaging", E.R. McCarney, S. Han, J. Magn. Reson. 190 (2008), 307-315.
"Dynamic Nuclear Polarization Enhanced Magnetic Resonance Analysis at 9.8 GHz using Amplified 1H Water Signal", S. Han and E. R. McCarney, in S. Codd, J. Seymour (Eds.) "Magnetic Resonance Microscopy", Wiley-VCH, Weinheim, Germany, 2008.
"A New Model for Overhauser Enhanced Nuclear Magnetic Resonance Using Nitroxide Radicals", B. D. Armstrong, S. Han, J. Chem. Phys. 127 (9) (2007).
"Hyperpolarized water as an authentic magnetic resonance imaging contrast agent", E. R. McCarney, B. L. Armstrong, M. D. Lingwood, S. Han, Proc. Nat. Acad. Sci. USA. 104 (6) (2007) 1754-1759.
"Para-hydrogen induced polarization in heterogeneous hydrogenation reactions", I.V. Koptyug, K.V. Kovtunov, S.R. Burt, M.S. Anwar, C. Hilty, S. Han, A. Pines, R.Z. Sagdeev, J. Am. Chem. Soc. 129 (17) (2007) 5580-5586
S. Stapf, S. Han, "Nuclear Magnetic Resonance Imaging", Ullmann Encyclopedia Article, Wiley-VCH, Germany, in press, 2007.
S. Han, S. Stapf, "Fluid flow and trans-membrane exchange in a hemodialyzer module", in S. Stapf, S. Han (Eds.) "NMR Imaging in Chemical Engineering"d Wiley-VCH, Weinheim, Germany, (2006).
S. Han, J. Granwehr, C. Hilty, "Broadening the application range of NMR and MRI by remote detection", in S. Stapf and S. Han (Eds) NMR Imaging in Chemical Engineering, Wiley-VCH, Weinheim, Germany (2006).
NMR Imaging in Chemical Engineering, S. Stapf and S. Han (Eds), Wiley-VCH, Weinheim, Germany (2006).