Publications

@article{,
title = {Fluorophore photostability and saturation in the hotspot of DNA origami nanoantennas},
author = {L Grabenhorst and K Trofymchuk and F Steiner and V Glembockyte and P Tinnefeld},
url = {http://dx.doi.org/10.1088/2050-6120/ab6ac8},
doi = {10.1088/2050-6120/ab6ac8},
issn = {2050-6120},
year = {2020},
date = {2020-02-05},
journal = {Methods and Applications in Fluorescence},
volume = {8},
number = {2},
pages = {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.},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}

@article{,
title = {Ultrafast Single-Molecule Fluorescence Measured by Femtosecond Double-Pulse Excitation Photon Antibunching},
author = {J Schedlbauer and P Wilhelm and L Grabenhorst and M E Federl and B Lalkens and F Hinderer and U Scherf and S H\"{o}ger and P Tinnefeld and S Bange and J Vogelsang and J M Lupton},
url = {https://doi.org/10.1021/acs.nanolett.9b04354},
doi = {10.1021/acs.nanolett.9b04354},
issn = {1530-6984},
year = {2019},
date = {2019-12-23},
journal = {Nano Letters},
keywords = {Foundry Organic, Molecularly-Functionalized},
pubstate = {published},
tppubtype = {article}
}

@article{,
title = {Optimizing the Size of Platinum Nanoparticles for Enhanced Mass Activity in the Electrochemical Oxygen Reduction Reaction},
author = {B Garlyyev and K Kratzl and M R\"{u}ck and J Michali\v{c}ka and J Fichtner and J M Macak and T Kratky and S G\"{u}nther and M Cokoja and A S Bandarenka and A Gagliardi and R A Fischer},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201904492},
doi = {10.1002/anie.201904492},
issn = {1433-7851},
year = {2019},
date = {2019-05-03},
journal = {Angewandte Chemie International Edition},
volume = {58},
number = {28},
pages = {9596-9600},
abstract = {Abstract High oxygen reduction (ORR) activity has been for many years considered as the key to many energy applications. Herein, by combining theory and experiment we prepare Pt nanoparticles with optimal size for the efficient ORR in proton-exchange-membrane fuel cells. Optimal nanoparticle sizes are predicted near 1, 2, and 3 nm by computational screening. To corroborate our computational results, we have addressed the challenge of approximately 1 nm sized Pt nanoparticle synthesis with a metal\textendashorganic framework (MOF) template approach. The electrocatalyst was characterized by HR-TEM, XPS, and its ORR activity was measured using a rotating disk electrode setup. The observed mass activities (0.87±0.14 A mgPt−1) are close to the computational prediction (0.99 A mgPt−1). We report the highest to date mass activity among pure Pt catalysts for the ORR within similar size range. The specific and mass activities are twice as high as the Tanaka commercial Pt/C catalysis.},
keywords = {Foundry Organic, Solid-Liquid},
pubstate = {published},
tppubtype = {article}
}