title: DNA origami based Au-Ag-core-shell nanoparticle dimers with single-molecule SERS sensitivity.
abstract: DNA origami nanostructures are a versatile tool to arrange metal nanostructures and other chemical entities with nanometer precision. In this way gold nanoparticle dimers with defined distance can be constructed, which can be exploited as novel substrates for surface enhanced Raman scattering (SERS). We have optimized the size, composition and arrangement of Au/Ag nanoparticles to create intense SERS hot spots, with Raman enhancement up to 10(10), which is sufficient to detect single molecules by Raman scattering. This is demonstrated using single dye molecules (TAMRA and Cy3) placed into the center of the nanoparticle dimers. In conjunction with the DNA origami nanostructures novel SERS substrates are created, which can in the future be applied to the SERS analysis of more complex biomolecular targets, whose position and conformation within the SERS hot spot can be precisely controlled.
authors.affiliation: Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14469 Potsdam, Germany. bald@uni-potsdam.de.
authors.forename: J
authors.initials: J
authors.lastname: Prinz
authors.affiliation: Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14469 Potsdam, Germany. bald@uni-potsdam.de and BAM Federal Institute for Materials Research and Testing, Richard-Willstätter Str. 11, 12489 Berlin, Germany and Department of Chemistry + SALSA, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Heck
authors.affiliation: Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14469 Potsdam, Germany. bald@uni-potsdam.de.
authors.forename: L
authors.initials: L
authors.lastname: Ellerik
authors.affiliation: Department of Chemistry + SALSA, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Merk
authors.affiliation: Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14469 Potsdam, Germany. bald@uni-potsdam.de and BAM Federal Institute for Materials Research and Testing, Richard-Willstätter Str. 11, 12489 Berlin, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Bald
mesh_terms: D002232:Carbocyanines / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D019281:Dimerization; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology / Q000379:methods*; D009693:Nucleic Acid Hybridization; D012235:Rhodamines / Q000737:chemistry; D012542:Scattering, Radiation; D012825:Silicon / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
chemical_list: C114557:5-carboxytetramethylrhodamine succinimidyl ester; D002232:Carbocyanines; D004277:DNA, Single-Stranded; D012235:Rhodamines; C089187:cyanine dye 3; D012834:Silver; D006046:Gold; D004247:DNA; D012825:Silicon