Proceedings Article | 15 March 2018
KEYWORDS: Nanostructures, Biosensing, Nanoparticles, Surface enhanced Raman spectroscopy, Molecules, Luminescence, Fluorescent markers, Metals, Receptors, Raman spectroscopy
DNA origami nanostructures allow for the precise placement of functional entities such as fluorescent dyes, metal nanoparticles and receptor molecules such as DNA aptamers. This makes them an ideal platform to create novel fluorescence and Raman based chemo- and biosensors. Compared to other fluorescent labels functionalized DNA origami nanostructures can be brighter and thus more sensitive than other fluorescent labels and they possess a well-defined number of fluorescent dyes with well-defined inter-dye distance. In this way optimized light-harvesting multichromophore labels can be prepared,[1] which allows for the generation of self-referenced sensors based on Förster resonance energy transfer (FRET).[2] By attaching gold or silver nanoparticles to the DNA origami nanostructures a direct chemical information of analytes can be obtained by surface-enhanced Raman scattering (SERS).[3] Intense SERS hot spots can be formed by creating nanoparticle dimers [3] or trimers [4] (nanolenses) with well-defined inter-particle gap. In addition to the precise arrangement of nanoparticles the DNA origami nanostructures also allow for a specific binding of analyte molecules exactly in the SERS hot spots. In this presentation the detection of micro-RNA, ions and proteins using DNA origami nanostructures by fluorescence and SERS spectroscopy, respectively, will be demonstrated as a proof-of-principle.
[1] L. Olejko, I. Bald, RSC Adv. 2017, 7, 23924
[2] L. Olejko, P. Cywinski, I. Bald, Angew. Chem. 2015, 127, 683.
[3] J. Prinz et al., Nanoscale 2016, 8, 5612.
[4] C. Heck et al., ACS Photonics 2017, 4, 1123.
