PHYS/ASTR Colloquium: "Everything You Need to Know about TERS and More" - Patrick Z. El-Khoury (Senior Research Scientist, Pacific Northwest National Laboratory)

San Francisco State University

Physics & Astronomy Colloquium Series

Monday, March 4, 2024

Thornton Hall 411, 3:30 PM

Speaker: Patrick Z. El-Khoury (Senior Research Scientist, Pacific Northwest National Laboratory)

Host: Huizhong Xu

Title: Everything You Need to Know about TERS and More

Abstract: 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.