123rd General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation of Young Material Chemists
Room No. Room 405+406
Time THU 09:00-09:12
Code MAT.O-1
Subject Plasmonic nanogap engineering with DNA for biomedical application
Authors Jeong-Wook Oh, Jwa-Min Nam1,*
Department of Chemistry, Seoul National University, Korea
1Division of Chemistry, Seoul National University, Korea
Abstract Plasmonic nanogaps can intensify electromagnetic field in their confined narrow areas, which enable to provide superior optical enhancement such as surface-enhanced Raman scattering (SERS). A narrower nanogap is more beneficial in magnifying electromagnetic filed, but in fact, ~1 nm nanogap is represented as the most efficient for enhancing SERS signal due to the quantum tunneling effect. We synthesized ~1-nm plasmonic nanogap nanoparticles producing strong SERS signal. DNA-modified gold nanoparticles (AuNPs) were served as a seed, which was followed by Au growth on the seed AuNPs. ~1-nm uniform nanogap was formed with several bridges between a core AuNP and an Au shell, and we call those particles as gold-nanobridged nanogap particles (Au-NNPs). The nanogaps can be controlled by the DNA sequence and DNA grafting density. Interestingly, the exterior surface roughness of Au-NNP can induce amplification of the electromagnetic field inside the nanogap, increasing the SERS signal by ~1 order of magnitude. Due to the strong and uniform SERS effect, Au-NNPs were used as a SERS probe for biosensor and bioimaging. Herein, the synthetic mechanism and the optical properties of ultrasmall nanogap inside plasmonic nanoparticles can provide valuable guidelines for developing new plasmonic nanogap structures and their biomedical applications.
E-mail eqcm2@snu.ac.kr