Celebrating differences: A single-molecule approach to DNA nanotechnology

One of the remarkable properties natural photosynthetic machinery is that remarkably high quantum efficiency can be achieved with a relatively scant suite components:1Krüger T.P.J. van Grondelle R. Design principles light-harvesting as revealed by single molecule spectroscopy.Physica B Condens Matter. 2016; 480: 7-13https://doi.org/10.1016/j.physb.2015.08.005Crossref Scopus (8) Google Scholar basic schema described collection chromophores, workhorses light harvesting, held in precise positions protein scaffold. Yet, from simple chemical building blocks emerge sophisticated photophysical behavior, which still being dissected. Since its first experimental demonstration,2Orrit M. Bernard J. Single pentacene molecules detected fluorescence excitation p-terphenyl crystal.Phys. Rev. Lett. 1990; 65: 2716-2719https://doi.org/10.1103/PhysRevLett.65.2716Crossref PubMed (870) single-molecule spectroscopy has been regularly used on variety systems to discern complex heterogeneous and asynchronous behaviors, particularly those direct result scaffold conditions. Although many recent advances have made understanding how scaffolds control photophysics, difficulties systematically manipulating so far it difficult generalize kind constraints impose chromophores order optimize capture transport energy. This presents notable gap knowledge fundamental harvesting because ability devices use itself diversify pathways across multiple timescales, especially under ambient conditions, responsible for function both bio-inspired devices.3Fresch E. Meneghin Agostini A. Paulsen H. Carbonera D. Collini How environment tune energy, coupling, ultrafast dynamics interacting chlorophylls: example water-soluble chlorophyll protein.J. Phys. Chem. 2020; 11: 1059-1067https://doi.org/10.1021/acs.jpclett.9b03628Crossref (12) Scholar,4Kondo T. Pinnola Chen W.J. Dall’Osto L. Bassi Schlau-Cohen G.S. Single-molecule LHCSR1 identifies two distinct states multi-timescale photoprotection.Nat. 2017; 9: 772-778https://doi.org/10.1038/nchem.2818Crossref Therefore, combination DNA nanotechnology an exciting step toward bottom-up approach structural-functional relationship devices. In this issue Chem, my colleagues I employ novel phosphoramidite chemistry incorporate doubly linked Cy3, onto varying complexity confocal look at differences lifetime distribution Cy3 arise when changed duplex more rigid double-crossover (DX) tiles5Hart S.M. Banal J.L. Bricker W.P. Dodin Markova Vyborna Y. Willard A.P. Häner Bathe Engineering couplings exciton using synthetic scaffolds.Chem. 2021; 7: 752-773Abstract Full Text PDF (14) (Figure 1A). prime tool investigating heterogeneity any system, physiological where thermal noise ensemble averaging often obfuscate energetic and/or conformational subpopulations. our case, ensemble-averaged technique recovered same regardless chromophore was scaffolded, microscope we discovered added rigidity DX tile constrained such electronic excited displayed ∼4-fold decrease comparison scaffolded 1C). other words, increase decreases associated chromophore. By simulation, found most likely difference rigidity, therefore accessibility chromophore, given restricts kinking 1D). suggests general controlling tuning scaffold, or bath, oftentimes experimentally tenable. We were surprised discover that, although reduces excited-state lifetimes, structural attribute slows down depolarization time 1B). discovery led realization much nuanced interpretation energy transfer than typical assumptions employed resonance energy-transfer experiments (dynamic averaging; Figure 1E) required one deals fluctuations occur timescales similar transfer. Namely, each possible position must considered static state, leading range efficiencies all accounted (static 1E). new field directions pursue. nanotechnology, now break otherwise complex, interdependent energy-transduction networks methodically interrogate component system. will hopefully spur types inquiries likewise systems, information condensed-phase supramolecular constructs. Being PhD student Prof. exposed me these spectroscopic techniques and, perhaps importantly, really tightened method scientific investigation. Our collaborators labs always interesting designs share me. continue awed every day sheer versatility creativity nanotechnology. The group shown just important numerical molecular modeling sciences, moves grappling underlie increasingly massive, noisier assemblies. It pleasure work scientists incredibly varied backgrounds expertise. As science becomes interdisciplinary, feel extremely lucky able take part exercise graduate am only eager answer complicated questions time. Watching speed lightStephanie HartChemMarch 1, 2021In BriefIt notoriously challenging bioinspired degrees freedom play. Stephanie Hart discusses development tunable excitonic platform MIT University Bern. Time-resolved computational methods allowed researchers disentangle parameters behind systems. extrapolated design DNA-based circuitry. Full-Text Open ArchiveEngineering scaffoldsHart et al.ChemJanuary 14, BriefExcitonic condensed phase are controlled electrodynamic between surrounding environment. Here, develop characterize multidimensional spectroscopy, simulations. Leveraging tunability platform, explore role transport. ArchiveWeaving strands energyJames BanalChemMarch BriefDNA self-assembly provides diverse toolbox program spatiotemporal characteristics aggregates leveraged carefully dissecting behavior excitons condensed-matter Potential Energy article, James vignette structure dye steer Archive