Fluorophore photostability and saturation in the hotspot of DNA origami nanoantennas

Grabenhorst, Lennart ; Trofymchuk, Kateryna; Steiner, Florian ; Glembockyte, Viktorija und Tinnefeld, Philip (5. Februar 2020): Fluorophore photostability and saturation in the hotspot of DNA origami nanoantennas. In: Methods and Applications in Fluorescence, Bd. 8, Nr. 2, 024003

Abstract

Fluorescent dyes used for single-molecule spectroscopy can undergo millions of excitation-emission cycles before photobleaching. Due to the upconcentration of light in a plasmonic hotspot, the conditions for fluorescent dyes are even more demanding in DNA origami nanoantennas. Here, we briefly review the current state of fluorophore stabilization for single-molecule imaging and reveal additional factors relevant in the context of plasmonic fluorescence enhancement. We show that despite the improved photostability of single-molecule fluorophores by DNA origami nanoantennas, their performance in the intense electric fields in plasmonic hotspots is still limited by the underlying photophysical processes, such as formation of dim states and photoisomerization. These photophysical processes limit the photon count rates, increase heterogeneity and aggravate quantification of fluorescence enhancement factors. These factors also reduce the time resolution that can be achieved in biophysical single-molecule experiments. Finally, we show how the photophysics of a DNA hairpin assay with a fluorophore-quencher pair can be influenced by plasmonic DNA origami nanoantennas leading to implications for their use in fluorescence-based diagnostic assays. Especially, we show that such assays can produce false positive results by premature photobleaching of the dark quencher

• Dokumententyp: Zeitschriftenartikel
• EU Funded Grant Agreement Number: 737089
• EU-Projekte: Horizon 2020 > Future & Emerging Technologies Program > 737089: ChipScope - Overcoming the Limits if Diffraction with Super-Resolution Lighting on a Chip
• Publikationsform: Publisher's Version
• Fakultät: Chemie und Pharmazie > Department Chemie
• Fakultätsübergreifende Einrichtungen: Center for NanoScience (CENS) ; Nanosystems Initiative Munich (NIM)
• Themengebiete: 500 Naturwissenschaften und Mathematik > 500 Naturwissenschaften ; 500 Naturwissenschaften und Mathematik > 530 Physik ; 500 Naturwissenschaften und Mathematik > 540 Chemie ; 500 Naturwissenschaften und Mathematik > 570 Biowissenschaften; Biologie
• ISSN: 2050-6120
• Sprache: Englisch