title: Highly sensitive SERS analysis of the cyclic Arg-Gly-Asp peptide ligands of cells using nanogap antennas.
abstract: The cyclic RGD (cRGD) peptide ligands of cells have become widely used for treating several cancers. We report a highly sensitive analysis of c(RGDfC) using surface enhanced Raman spectroscopy (SERS) using single dimer nanogap antennas in aqueous environment. Good agreement between characteristic peaks of the SERS and the Raman spectra of bulk c(RGDfC) with its peptide's constituents were observed. The exhibited blinking of the SERS spectra and synchronization of intensity fluctuations, suggest that the SERS spectra acquired from single dimer nanogap antennas was dominated by the spectrum of single to a few molecules. SERS spectra of c(RGDfC) could be used to detect at the nanoscale, the cells' transmembrane proteins binding to its ligand. SERS of cyclic RGD on nanogap antenna.
authors.affiliation: Department of Chemical Science and Engineering, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Portela
authors.affiliation: Department of Chemical Science and Engineering, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan.
authors.forename: Taka-Aki
authors.initials: TA
authors.lastname: Yano
authors.affiliation: Nanophotonics and Metrology Laboratory, Swiss Federal Institute of Technology Lausanne, Lausanne, CH-1015, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Santschi
authors.affiliation: Nanophotonics and Metrology Laboratory, Swiss Federal Institute of Technology Lausanne, Lausanne, CH-1015, Switzerland.
authors.forename: Olivier J F
authors.initials: OJ
authors.lastname: Martin
authors.affiliation: Bioengineering Department, Engineering School, The University of Tokyo, Bunkyo-ku, 113-8656, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tabata
authors.affiliation: Department of Chemical Science and Engineering, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hara
mesh_terms: D008024:Ligands; D036103:Nanotechnology; D010456:Peptides, Cyclic / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
chemical_list: D008024:Ligands; D010456:Peptides, Cyclic; C507169:cyclic arginine-glycine-aspartic acid peptide
keywords: Raman; SERS; biophotonics; cyclic RGD; fluctuations; nanogap antennas; plasmonic