title: Fluorescence near-field microscopy of DNA at sub-10 nm resolution.
abstract: We demonstrate apertureless near-field microscopy of single molecules at sub-10 nm resolution. With a novel phase filter, near-field images of single organic fluorophores were obtained with approximately sixfold improvement in the signal-to-noise ratio. The improvement allowed pairs of molecules separated by approximately 15 nm to be reliably and repeatedly resolved, thus demonstrating the first true Rayleigh resolution test for near-field images of single molecules. The potential of this technique for biological applications was demonstrated with an experiment that measured the helical rise of A-form DNA.
authors.affiliation: Applied Physics and Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Ziyang
authors.initials: Z
authors.lastname: Ma
authors.forename: Jordan M
authors.initials: JM
authors.lastname: Gerton
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Wade
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Quake
mesh_terms: D000465:Algorithms; D002232:Carbocyanines / Q000737:chemistry; D044704:DNA, A-Form / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009690:Nucleic Acid Conformation; D012825:Silicon
chemical_list: D002232:Carbocyanines; D044704:DNA, A-Form; D005456:Fluorescent Dyes; C089187:cyanine dye 3; D012825:Silicon