title: Femtomolar DNA detection by parallel colorimetric darkfield microscopy of functionalized gold nanoparticles.
abstract: We introduce a sensing platform for specific detection of DNA based on the formation of gold nanoparticles dimers on a surface. The specific coupling of a second gold nanoparticle to a surface bound nanoparticle by DNA hybridization results in a red shift of the nanoparticle plasmon peak. This shift can be detected as a color change in the darkfield image of the gold nanoparticles. Parallel detection of hundreds of gold nanoparticles with a calibrated true color camera enabled us to detect specific binding of target DNA. This enables a limit of detection below 1.0×10(-14) M without the need for a spectrometer or a scanning stage.
authors.affiliation: MESA+ Institute for Nanotechnology, University of Twente, AE Enschede, The Netherlands. r.verdoold@utwente.nl
authors.forename: Remco
authors.initials: R
authors.lastname: Verdoold
authors.forename: Ron
authors.initials: R
authors.lastname: Gill
authors.forename: Felicia
authors.initials: F
authors.lastname: Ungureanu
authors.forename: Robert
authors.initials: R
authors.lastname: Molenaar
authors.forename: Rob P H
authors.initials: RP
authors.lastname: Kooyman
mesh_terms: D003124:Colorimetry / Q000295:instrumentation* / Q000379:methods; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D008853:Microscopy / Q000295:instrumentation / Q000379:methods; D009693:Nucleic Acid Hybridization
chemical_list: D006046:Gold; D004247:DNA