About the Seminar:
The manipulation of light near the apex of a metallic nano-tip has enabled single molecule detection, identification, and imaging. The distinct advantages of the so-called tip-enhanced optical nano-spectroscopy/nano-imaging approaches are self-evident: ultra-high spatial resolution (nanometer or better) and the ultimate sensitivity (down to yoctomolar) are both attainable, all while retaining the ability to chemically fingerprint one molecule at a time (e.g., through Raman scattering). An equally interesting aspect of the same approach stems from using the properties of molecules to characterize the environments in which they reside. This concept of spectroscopy on the left hand side of the Schrödinger equation is certainly not novel and has been discussed in pioneering single molecule studies that ultimately led to a Nobel prize in chemistry. That said, local environment mapping through ultrasensitive optical spectroscopy acquires a unique flavor when executed using tip-enhanced Raman scattering (TERS). TERS on the left hand side of the Schrödinger equation is the major topic of this talk. The talk will also highlight complementary multimodal (non)linear nano-optical measurements that target plasmonic nanoparticles and nanostructures, and that are aimed at visualizing and understanding the nanoscopic optical fields that allow enhanced nano-spectroscopy and nano-imaging of molecular and materials systems.
About the Speaker:
Patrick El-Khoury received a BS in chemistry from the American University of Beirut (2003−2006, advisor: B. R. Kaafarani), a doctorate in photochemical sciences from Bowling Green State University (2006−2010, advisor: A. N. Tarnovsky), and postdoctoral training at the University of California, Irvine (2010−2012, advisor: V. A. Apkarian). Soon after, he joined Pacific Northwest National Laboratory (PNNL) as a Linus Pauling Distinguished Postdoctoral Research fellow (2013−2016, mentor: Wayne P. Hess). Currently, Patrick is a staff scientist in the Chemical Physics and Analysis group, within the Physical Sciences Division at PNNL. Among other things, he spends his days worrying about (bio)molecules, plasmons, and their interactions as gauged through tip-enhanced optical nanospectroscopy and nanoimaging.
