title: Permanent fixing or reversible trapping and release of DNA micropatterns on a gold nanostructure using continuous-wave or femtosecond-pulsed near-infrared laser light.
abstract: The use of localized surface plasmons (LSPs) for highly sensitive biosensors has already been investigated, and they are currently being applied for the optical manipulation of small nanoparticles. The objective of this work was the optical trapping of λ-DNA on a metallic nanostructure with femtosecond-pulsed (fs) laser irradiation. Continuous-wave laser irradiation, which is generally used for plasmon excitation, not only increased the electromagnetic field intensity but also generated heat around the nanostructure, causing the DNA to become permanently fixed on the plasmonic substrate. Using fs laser irradiation, on the other hand, the reversible trapping and release of the DNA was achieved by switching the fs laser irradiation on and off. This trap-and-release behavior was clearly observed using a fluorescence microscope. This technique can also be used to manipulate other biomolecules such as nucleic acids, proteins, and polysaccharides and will prove to be a useful tool in the fabrication of biosensors.
authors.affiliation: Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Shoji
authors.forename: Junki
authors.initials: J
authors.lastname: Saitoh
authors.forename: Noboru
authors.initials: N
authors.lastname: Kitamura
authors.forename: Fumika
authors.initials: F
authors.lastname: Nagasawa
authors.forename: Kei
authors.initials: K
authors.lastname: Murakoshi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yamauchi
authors.forename: Syoji
authors.initials: S
authors.lastname: Ito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyasaka
authors.forename: Hajime
authors.initials: H
authors.lastname: Ishihara
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Tsuboi
mesh_terms: D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects; D004574:Electromagnetic Fields; D006046:Gold / Q000737:chemistry*; D007259:Infrared Rays; D007834:Lasers; D008856:Microscopy, Fluorescence; D049329:Nanostructures / Q000737:chemistry*; D052898:Optical Tweezers; D020349:Surface Plasmon Resonance
chemical_list: D006046:Gold; D004247:DNA