EECS Seminar: Single-Particle Tracking Multiplex Raman Imaging of Targeting-Peptide Attached Au-Nanobridged Nanogap Particles Moving Inside a Single Live Cell

Yung Doug Suh
McDonnell Douglas Engineering Auditorium
Yung Doug Suh, PhD

Abstract: Imaging individual nanoparticles with multiplexing capabilities is of paramount interest for future applications of drug delivery, multiplexing cell-based assays for drug screening, and multiplexing in vitro diagnosis. Raman-active nanoparticle strategy such as multiply Raman-dye coded SERS-tag can be a good candidate for these future applications, but has suffered SERS signal inhomogeneity problems depending on SERS enhancement factors (EF) of each specific site where Raman dyes are either covalently or non-covalently attached. We have previously reported the Au-NNPs (Au-Nanobridged Nanogap Particles), which shows a narrow distribution of SERS EF 1,2, as well as a long-term real-time tracking technology for individual upconverting nano particles (UCNPs) inside a single live cell 3,4. We now combined the above mentioned multi-color Raman-dye tagged Au-NNPs with the long-term, real-time tracking wide-field imaging technology to develop Raman-based multiplexing imaging of individual Raman-active nanoparticles within a single live cell. To enhance the Raman signal enough for identifying and imaging even inside a live cell, we have optimized nanogap plasmon inside the Au-NNPs 1,2. Internal nanogap on the order of 1 nm plays a key role to stably enhance Raman signal of these Au-NNPs(Nanobridged Nanogap Particles). We have first tested multiplexing imaging capabilities of these Au-NNPs implanted with five different Raman dyes whose Raman spectra do not overlap each other in between the gold core and gold shell nanogap region dispersed on thenslide cover. Then we have applied these Au-NNPs onto a single live cell to take their movie moving inside a live cell. We have successfully imaged individual trajectories of these Au-NNPs inside a single live cell with a related technique that we have used to image individual trajectories of upconverting nanoparticles (UCNPs) 3,4. Single-particle tracking movie of targeting event toward the mitochondria inside a single HeLa living cell using the peptide-attached Au-NNPs will be presented.

Biography: Yung Doug Suh studied at Seoul National University for his BS (1991), MS (1993), and Ph.D. (1999) under the guidance of Seong Keun Kim in the chemistry department, Young Kuk in the physics department and Dongho Kim at the Korea Research Inst. of Standards and Science (KRISS), researching gas-phase molecular reaction dynamics, surface physics with UHV-STM, and laser spectroscopies, respectively. After finishing his postdoctoral research at ETH Zurich working with Renato Zenobi in 1999-2000,where he co-invented TERS(Tip-enhanced Raman Scattering), he worked at the Pacific Northwest Nat’l Laboratory (PNNL), USA, 2001-2002, doing single molecule spectroscopy. He accepted a recruited principal research scientist position in 2003, to form his own research group: Laboratory for Advanced Molecular Probing (LAMP) at the Korea Research Institute of Chemical Technology (KRICT) in DaeJeon, South Korea. Suh is currently a director of the Research Center for Convergence Nanobiotechnology, KRICT, and also serves as an adjunct professor of chemical engineering at SungKyunKwan Univerisity (SKKU) in South Korea since March 2013.