Eventos
O xoves 16 de xaneiro de 2025, o Prof. Guillermo Pedro Acuña (Department of Physics, University of Fribourg, Switzerland) ofrecerá o seminario “DNA nanotechnology for nanophotonics" dentro do ciclo CINBIO Seminar Programme.
Será ás 11:00 horas na Sala de seminarios de Torre CACTI.
ABSTRACT:
Over the last decade, the DNA origami technique [1] has consolidated into the state-of-the-art approach for the self-assembly of nanophotonic [2] structures since it provides unique control and versatility to organize different molecules and nanoparticles in well-defined geometric arrangements. In particular, this technique has proven extremely useful to fabricate nanophotonic devices with specific functionality by setting single-photon emitters, such as fluorescent molecules or quantum dots, and metallic nanoparticles in precise geometries with high positional and stoichiometric control.
In this contribution, we will first introduce this technique and discuss its strengths and limitations together with a comparison with state-of-the-art top-down approaches. Then we will show how this technique can be applied to study light-matter interaction at the single molecule level for enhanced spectroscopies [3] and how these antennas can be engineered to manipulate the fluorescence emission [4], including directivity [5], [6] and emission spectrum [7].
In addition, we will discuss our recent results on the development of a technique to functionalize high-index dielectric colloidal Si NPs [8] with DNA sequences using click-chemistry. To further demonstrate these findings, we self-assemble Si NP dimers using the DNA origami technique. Furthermore, we also exploit the DNA origami technique to position both Si NPs and organic fluorophores at controlled gaps to study the distance dependance energy transfer, the modification on the fluorescence rates and the emission directivity. Our results show that in the vicinity of the Si NPs the radiate rate increases more than the non-radiative rate and that the Kerker condition can be exploited to obtain emission unidirectionality.
Finally, we focused on manipulating the orientation of single dyes on DNA origami in order to control the coupling with optical antennas. In particular, we exploit the ability of DNA origami to exert forces in order to “stretch” covalently incorporated dyes and deterministically align them with the orientation of double-stranded DNA helix they are located at [9].
References
[1] P. W. K. Rothemund, “Folding DNA to create nanoscale shapes and patterns,” Nature, vol. 440, no. 7082. pp. 297–302, 2006. doi: 10.1038/nature04586.
[2] A. Kuzyk, R. Jungmann, G. P. Acuna, and N. Liu, “DNA Origami Route for Nanophotonics,” ACS Photonics, vol. 5, no. 4, pp. 1151–1163, Apr. 2018, doi: 10.1021/acsphotonics.7b01580.
[3] G. P. Acuna, F. M. Möller, P. Holzmeister, S. Beater, B. Lalkens, and P. Tinnefeld, “Fluorescence enhancement at docking sites of DNA-directed self-assembled nanoantennas,” Science (80-. )., vol. 338, no. 6106, pp. 506–510, 2012, doi: 10.1126/science.1228638.
[4] K. Hübner et al., “Directing Single-Molecule Emission with DNA Origami-Assembled Optical Antennas,” Nano Lett., vol. 19, no. 9, pp. 6629–6634, Sep. 2019, doi: 10.1021/acs.nanolett.9b02886.
[5] A. T. M. Yeşilyurt et al., “Unidirectional Meta-Emitters Based on the Kerker Condition Assembled by DNA Origami,” ACS Nano, Sep. 2023, doi: 10.1021/acsnano.3c05649.
[6] F. Zhu et al., “DNA-Templated Ultracompact Optical Antennas for Unidirectional Single-Molecule Emission,” Nano Lett., vol. 22, no. 15, pp. 6402–6408, doi: 10.1021/acs.nanolett.2c02424.
[7] M. Sanz-Paz, F. Zhu, N. Bruder, K. Kołątaj, A. I. Fernández-Domínguez, and G. P. Acuna, “DNA Origami Assembled Nanoantennas for Manipulating Single-Molecule Spectral Emission,” Nano Lett., Jun. 2023, doi: 10.1021/acs.nanolett.3c01818.
[8] H. Negoro, H. Sugimoto, and M. Fujii, “Helicity-Preserving Optical Metafluids,” Nano Lett., vol. 23, no. 11, pp. 5101–5107, Jun. 2023, doi: 10.1021/acs.nanolett.3c01026.
[9] A. Adamczyk et al., “DNA Self-Assembly of Single Molecules with Deterministic Position and Orientation,” ACS Nano, vol. 16, no. 10, pp. 16924–16931, doi: 10.1021/acsnano.2c06936.
BIO:
Since 2018 Guillermo Pedro Acuna is a Full Professor at the Physics department of the University of Fribourg where he leads the Photonic Nanosystems group. He has pioneered the use of the DNA origami technique for nanophotonics focusing on the fabrication of optical antennas for enhanced spectroscopies. Prof. Acuna obtained his Physics diploma at the Universidad de Buenos Aires (2005) and his PhD degree at the LMU München (2010) under the supervision of Prof. Roland Kersting. He has done a Post-Doc at Prof. Hermann Gaub´s chair for Bio-physics at the LMU München (2010). From 2011 till 2017 he was group leader at Prof. Philip Tinnefeld´s chair at the Technical University of Braunschweig. In 2018, Prof. Acuna obtained a Full Professor (W3) position at the University of Rostock. His main interests are nanophotonics, plasmonics, DNA nanotechnology, nanoscopy, single molecule techniques and sensing.
