@article{60082, author = {{Keller, Adrian}}, journal = {{Nucleic Acid Insights}}, number = {{2}}, pages = {{61–75}}, title = {{{DNA origami nanostructures in biomedicine and the issue of stability}}}, doi = {{10.18609/nuc.2025.011}}, volume = {{2}}, year = {{2025}}, } @inproceedings{62814, abstract = {{Porous carbons are prominent electrode materials in energy storage applications such as supercapacitors. However, rational materials development is hampered by difficulties in interpreting electrochemical impedance spectra (EIS) and drawing conclusions about promising aspects of device improvement. Here, we characterized electrodes consisting of activated carbon with polyacrylic acid binder in four different concentrations of sulfuric acid, using cyclic voltammetry and electrochemical impedance spectroscopy. Both datasets were evaluated with simple equivalent circuits and comparatively analyzed. Conductivity of the electrolyte was independently measured. Cyclic voltammograms (CV) show larger resistance and capacitance at low scan rates. Resistances obtained from EIS are in good agreement with those obtained by cyclic voltammograms particularly at high scan rates. The comparison against specific electrolyte resistance can reveal whether resistances within the solid electrode architecture or resistances within the electrolyte, partially confined by pores, are the dominant cause of increased resistance at low scan rate. Comparison between CV and EIS points to the main electrode capacitance being described by a constant phase element (CPE) used to fit the low-frequency region of EIS.}}, author = {{Reinke, Sebastian and Khamitsevich, Vera and Linnemann, Julia}}, booktitle = {{2024 International Workshop on Impedance Spectroscopy (IWIS)}}, keywords = {{electrochemical impedance spectroscopy, distorted cyclic voltammograms, supercapacitors, carbon}}, publisher = {{IEEE}}, title = {{{Complementary Analysis of Cyclic Voltammograms and Impedance Spectra of Porous Carbon Electrodes}}}, doi = {{10.1109/iwis63047.2024.10847115}}, year = {{2025}}, } @article{61821, abstract = {{AbstractControlling the surface orientation of DNA origami nanostructures (DON) is crucial for applications in nanotechnology and materials science. While previous work utilized various DON modifications, simple methods for controlling their landing orientation remain scarce. Here, we demonstrate a straightforward approach to control the adsorption orientation of chiral double‐L (CDL) DON on mica by tuning magnesium ion (Mg2⁺) concentration and exploiting global shape distortions. Using atomic force microscopy (AFM), we analyzed the resulting distribution of the mirror‐image orientations, referred to as S and Z orientations, at both buffer/mica and air/mica interfaces and identified conditions resulting in homogenous CDL orientation of 100% S. These results demonstrate how DON conformation and ionic environments influence DON orientation, offering insights for precise nanostructure deposition.}}, author = {{Velpula, Gangamallaiah and Tomm, Emilia and Shen, Boxuan and Mali, Kunal S. and Keller, Adrian Clemens and De Feyter, Steven}}, issn = {{1433-7851}}, journal = {{Angewandte Chemie International Edition}}, publisher = {{Wiley}}, title = {{{Breaking of the Up‐Down Symmetry of DNA Origami on a Solid Substrate}}}, doi = {{10.1002/anie.202507613}}, year = {{2025}}, } @article{62798, abstract = {{We investigated electrodeposited nanoparticulate nickel selenide (pre)catalysts that transform into nickel oxides/oxyhydroxides under oxygen evolution reaction conditions in alkaline solutions. Previous studies of this transformation were conducted at lower current densities than those of industrial relevance (≥1 A cm–2). We used ultramicroelectrodes (UMEs) to achieve such current densities, benefiting from their small size, ensuring low absolute currents and low ohmic drop but high current densities. Morphological degradation of the catalyst material was only observed at current densities exceeding 1 A cm–2 but not for smaller ones. Using X-ray absorption, X-ray photoemission spectroscopy, and X-ray diffraction, we confirmed that the degradation was accompanied by the literature-known transformation of nanoparticulate Ni3Se2 (bulk)/NiSe (surface) into nickel oxyhydroxide. The transformation of the precatalyst goes along with a significant improvement in the charge transfer kinetics observed by decreasing Tafel slopes with ongoing experimental time extracted from cyclic voltammetry (CV) experiments and electrochemical impedance spectroscopy (EIS) in the high-frequency range. However, these kinetic improvements are accompanied by limitations in mass transport concluded from decreasing current responses at high overpotentials in CVs and increasing impedance in the low-frequency range of the EIS spectra after extended CV cycling. These mass transport limitations originated from morphological degradations at the UME exceeding 1 A cm–2 which we proved by applying identical location scanning electron microscopy. This has not been reported in studies that have been limited to lower current densities before. Our findings showcase how UMEs can be used to study (pre)catalysts (herein nickel selenides) under current densities of industrial relevance in the absence of ohmic drop-related ambiguities, combined with in-depth materials characterization studies, e.g., identical location microscopy and advanced spectroscopic methods. This approach enables direct evaluation and comparison of catalyst materials and thus demonstrates how to overcome long-standing limitations of electrocatalyst design and testing.}}, author = {{Hiege, Felix and Chang, Chun-Wai and Trost, Oliver and van Halteren, Charlotte E. R. and Hosseini, Pouya and Bendt, Georg and Schulz, Stephan and Feng, Zhenxing and Linnemann, Julia and Tschulik, Kristina}}, issn = {{1944-8244}}, journal = {{ACS Applied Materials & Interfaces}}, keywords = {{Electrocatalysis, oxygen evolution reaction, nickel selenide, microelectrode}}, number = {{29}}, pages = {{41893--41903}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Morphological Degradation of Oxygen Evolution Reaction-Electrocatalyzing Nickel Selenides at Industrially Relevant Current Densities}}}, doi = {{10.1021/acsami.5c05381}}, volume = {{17}}, year = {{2025}}, } @article{62876, abstract = {{ABSTRACT Spin‐coated polylactide (PLA) thin films were exposed to nitrogen plasma for varying time intervals. The progressive etching of the PLA film in direct contact with the nitrogen plasma was monitored in situ using polarization modulated infrared reflection absorption spectroscopy (PM‐IRRAS). No appreciative changes in composition were seen with PM‐IRRAS, indicating that the etching did not significantly affect the bulk composition. Atomic force microscopy characterization of the plasma‐etched films showed that the PLA films are homogeneously etched. Subsequent ex situ XPS analysis of the treated surface revealed the presence of C‐N bonds in the surface‐near region that could be associated with amino and/or amide surface species. PLA films were also alternatively exposed to nitrogen ion beams produced by an electron‐cyclotron‐resonance (ECR) plasma source and were investigated in vacuo by XPS. This treatment revealed the partial substitution of surface oxygen species by nitrogen, resulting in a similar surface modification as in the plasma case. The comparison of XPS data and water contact angle studies suggest that the activated surfaces show a reorientation of macromolecular fragments in the surface‐near region depending on the polarity of the phase with which they are in contact. Under ultra‐high vacuum (UHV) conditions, the surface tends to lower its surface energy, while in contact with the aqueous phase, subsurface polar groups orientate outwards, which enables the formation of hydrogen bonds.}}, author = {{Gołębiowska, Sandra and Voigt, Markus and de los Arcos de Pedro, Maria Teresa and Grundmeier, Guido}}, issn = {{0142-2421}}, journal = {{Surface and Interface Analysis}}, number = {{7}}, pages = {{499--509}}, publisher = {{Wiley}}, title = {{{In Situ PM‐IRRAS and XPS Analysis of Nitrogen Plasma Surface Modification of Polylactide Thin Films}}}, doi = {{10.1002/sia.7406}}, volume = {{57}}, year = {{2025}}, } @article{62875, author = {{Theile-Rasche, Chantal and Wang, Fuzeng and Prüßner, Tim and Huck, Marten and Steinrück, Hans-Georg and de los Arcos de Pedro, Maria Teresa and Grundmeier, Guido}}, issn = {{0040-6090}}, journal = {{Thin Solid Films}}, publisher = {{Elsevier BV}}, title = {{{Evaluation of anti-adhesive and corrosion protection properties of TiAlSiN-magnetron-sputtered films for applications in polymer processing}}}, doi = {{10.1016/j.tsf.2025.140676}}, volume = {{820}}, year = {{2025}}, } @article{62874, abstract = {{DNA origami adsorption at single-crystalline TiO2 surfaces is investigated at different Mg2+ concentrations. For TiO2(001), DNA origami adsorption is stronger at 5 mM than at 10 mM Mg2+, whereas the opposite is observed for TiO2(110) and TiO2(111).}}, author = {{Xu, Xiaodan and Gołębiowska, Sandra and de los Arcos de Pedro, Maria Teresa and Grundmeier, Guido and Keller, Adrian}}, issn = {{2755-3701}}, journal = {{RSC Applied Interfaces}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{DNA origami adsorption at single-crystalline TiO2 surfaces}}}, doi = {{10.1039/d5lf00109a}}, year = {{2025}}, } @article{60568, author = {{Bocchini, Adriana and Kollmann, S. and Gerstmann, Uwe and Schmidt, Wolf Gero and Grundmeier, Guido}}, issn = {{0039-6028}}, journal = {{Surface Science}}, publisher = {{Elsevier BV}}, title = {{{Phosphonic acid adsorption on α-Bi2O3 surfaces}}}, doi = {{10.1016/j.susc.2025.122776}}, volume = {{760}}, year = {{2025}}, } @article{61982, abstract = {{Doped Co3O4 nanoparticles are investigated via spectro-electrochemistry in the (pre-) oxygen evolution reaction (OER) regime by tracing the absorption signal of the Co3+ d–d transition under applied bias for getting insight into the catalysts activation and the formation of catalytically active phases. In the low potential regime up to 1.37 VRHE, a rise in the optical absorption signal of the [Co3+]oct d–d transition is observed and attributed to a structural change from [Co2+]tet to [Co3+]oct due to an electrochemically induced surface restructuring with water. For applied potentials higher than 1.37 VRHE an overall offset of the absorption spectra in the UV–vis range, equivalent to a darkening of the materials is detected. This is attributed to the formation of a CoOx(OH)y skin layer as supported by high-energy X-ray diffraction (HE-XRD) measurements. We found that the kinetics of the Co3+ states are heavily influenced by the type of dopant with V-doped Co3O4 exhibiting stable Co3+ states (>20 min) while the Mn-doped Co3O4 Co3+ states reduce within 36 s under reductive bias. We conclude that doping Co3O4 with transition metals affects the formation and potential-dependent thickness of the CoOx(OH)y skin layer as the catalytically active phase and the formation of long-time stable surface Co3+ states after activation in the first OER cycle.}}, author = {{Kampermann, L. and Klein, J. and Wagner, T. and Kotova, A. and Placke-Yan, C. and Yasar, A. and Jacobse, L. and Lasagna, S. and Leppin, Christian and Schulz, S. and Linnemann, Julia and Bergmann, A. and Roldan Cuenya, B. and Bacher, G.}}, issn = {{2155-5435}}, journal = {{ACS Catalysis}}, keywords = {{electrocatalysis, oxygen evolution reaction, cobalt spinel, operando characterization, spectroelectrochemistry}}, number = {{21}}, pages = {{18391--18403}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Operando Analysis of the Pre-OER Activation of Metal-Doped Co3O4 Nanoparticle Catalysts}}}, doi = {{10.1021/acscatal.5c03900}}, volume = {{15}}, year = {{2025}}, } @article{60913, abstract = {{ABSTRACTSpin‐coated polylactide (PLA) thin films were exposed to nitrogen plasma for varying time intervals. The progressive etching of the PLA film in direct contact with the nitrogen plasma was monitored in situ using polarization modulated infrared reflection absorption spectroscopy (PM‐IRRAS). No appreciative changes in composition were seen with PM‐IRRAS, indicating that the etching did not significantly affect the bulk composition. Atomic force microscopy characterization of the plasma‐etched films showed that the PLA films are homogeneously etched. Subsequent ex situ XPS analysis of the treated surface revealed the presence of C‐N bonds in the surface‐near region that could be associated with amino and/or amide surface species. PLA films were also alternatively exposed to nitrogen ion beams produced by an electron‐cyclotron‐resonance (ECR) plasma source and were investigated in vacuo by XPS. This treatment revealed the partial substitution of surface oxygen species by nitrogen, resulting in a similar surface modification as in the plasma case. The comparison of XPS data and water contact angle studies suggest that the activated surfaces show a reorientation of macromolecular fragments in the surface‐near region depending on the polarity of the phase with which they are in contact. Under ultra‐high vacuum (UHV) conditions, the surface tends to lower its surface energy, while in contact with the aqueous phase, subsurface polar groups orientate outwards, which enables the formation of hydrogen bonds.}}, author = {{Golebiowska, Sandra Alicja and Voigt, Markus and de los Arcos, Teresa and Grundmeier, Guido}}, issn = {{0142-2421}}, journal = {{Surface and Interface Analysis}}, number = {{7}}, pages = {{499--509}}, publisher = {{Wiley}}, title = {{{In Situ PM‐IRRAS and XPS Analysis of Nitrogen Plasma Surface Modification of Polylactide Thin Films}}}, doi = {{10.1002/sia.7406}}, volume = {{57}}, year = {{2025}}, } @article{62936, author = {{Ruhm, Lukas and Neßlinger, Vanessa and Becker, Roman and Meschut, Gerson and Grundmeier, Guido}}, issn = {{0143-7496}}, journal = {{International Journal of Adhesion and Adhesives}}, publisher = {{Elsevier BV}}, title = {{{A contribution to the mechanistic understanding of the improvement of the delamination resistance of adhesives on steel by grit-blasting}}}, doi = {{10.1016/j.ijadhadh.2025.104147}}, volume = {{143}}, year = {{2025}}, } @article{62938, author = {{Müller, Hendrik and Cetin, Ali and Dahlmann, Rainer and de los Arcos, Teresa and Grundmeier, Guido}}, issn = {{0257-8972}}, journal = {{Surface and Coatings Technology}}, publisher = {{Elsevier BV}}, title = {{{Interface chemistry and adhesion of thin bilayer Si-organic PECVD barrier films on post-consumer recycled polypropylene}}}, doi = {{10.1016/j.surfcoat.2025.132392}}, volume = {{512}}, year = {{2025}}, } @article{62939, author = {{Su, Jiangling and Muhle, Marius and Nembot, Nelly and Prüßner, Tim and Xie, Xiaofan and Wittstock, Gunther and Grundmeier, Guido}}, issn = {{0013-4686}}, journal = {{Electrochimica Acta}}, publisher = {{Elsevier BV}}, title = {{{Spontaneous grafting of nitrobenzenediazonium salt on plasma-modified copper substrates}}}, doi = {{10.1016/j.electacta.2025.147810}}, volume = {{546}}, year = {{2025}}, } @article{58853, abstract = {{Abstract While being a promising approach for the treatment of infections caused by drug-resistant, pathogenic bacteria, the clinical implementation of phage therapy still faces several challenges. One of these challenges lies in the high strain-specificity of most bacteriophages, which makes it necessary to screen large phage collections against the target pathogens in order to identify suitable candidates for the formulations of personalized therapeutic phage cocktails. In this work, we evaluate the potential of quartz crystal microbalance with dissipation monitoring (QCM-D) to identify and detect phage infection and subsequent lysis of bacteria immobilized on the surfaces of the QCM-D sensors. Using lytic Escherichia coli phage T7 as a model, we show that phage infection of E. coli cells results in various unique alterations in the behaviors of the frequency (Δf) and dissipation (ΔD) signals, which are not observed during exposure of the E. coli strain to non-infectious Bacillus subtilis phage phi29 at similar concentration. To aid future phage screening campaigns, we furthermore identify a single measurement parameter, i.e., the spread between the different overtones of ΔD, that can be used to detect phage-induced lysis. For T7 infection of E. coli, this is achieved within 4 h after inoculation, including immobilization and growth of the bacteria on the sensor surface, as well as the completed phage propagation cycle. Given the commercial availability of highly automated multichannel systems and the fact that this approach does not require any sensor modifications, QCM-D has the potential to become a valuable tool for screening medium-sized phage collections against target pathogens. Graphical Abstract }}, author = {{Pothineni, Bhanu K. and Probst, René and Kiefer, Dorothee and Dobretzberger, Verena and Barišić, Ivan and Grundmeier, Guido and Keller, Adrian}}, issn = {{1618-2642}}, journal = {{Analytical and Bioanalytical Chemistry}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Monitoring phage infection and lysis of surface-immobilized bacteria by QCM-D}}}, doi = {{10.1007/s00216-025-05803-5}}, year = {{2025}}, } @article{60507, abstract = {{DNA origami nanostructures are powerful molecular tools for the controlled arrangement of functional molecules and thus have important applications in biomedicine, sensing, and materials science. The fabrication of DNA origami...}}, author = {{Tomm, Emilia and Grundmeier, Guido and Keller, Adrian}}, issn = {{2040-3364}}, journal = {{Nanoscale}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Cost-efficient folding of functionalized DNA origami nanostructures via staple recycling}}}, doi = {{10.1039/d5nr01435b}}, year = {{2025}}, } @article{60606, abstract = {{Streptavidin binding to DNA origami-supported high-density biotin arrays is investigated for selected experimental parameters. While bidentate binding and steric hindrance can be minimized, molecular crowding limits the binding yields in 2D arrays.}}, author = {{Rabbe, Lukas and Tomm, Emilia and Grundmeier, Guido and Keller, Adrian}}, issn = {{2046-2069}}, journal = {{RSC Advances}}, number = {{30}}, pages = {{24536--24543}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Toward high-density streptavidin arrays on DNA origami nanostructures}}}, doi = {{10.1039/d5ra03393d}}, volume = {{15}}, year = {{2025}}, } @article{60709, abstract = {{Self-assembled DNA origami lattices have promising applications in the fabrication of functional surfaces for sensing and plasmonics via molecular lithography. While surface-assisted DNA origami lattice assembly at mica surfaces is...}}, author = {{Omoboye, Adekunle and Pothineni, Bhanu and Grundmeier, Guido and She, Zhe and Keller, Adrian}}, issn = {{2755-3701}}, journal = {{RSC Applied Interfaces}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Surface potential-dependent assembly of DNA origami lattices at SiO2 surfaces}}}, doi = {{10.1039/d5lf00169b}}, year = {{2025}}, } @article{60973, abstract = {{The specific binding of DNA origami nanostructures (DONs) to bacteria is an important prerequisite for their application in pathogen targeting and antimicrobial drug delivery. So far, targeting bacteria with DONs has been achieved exclusively via aptamers, which suffer from drawbacks such as sensitivity toward environmental conditions and reduced binding after immobilization or conjugation. Here, an alternative approach is presented based on the modification of DONs with the cell wall‐binding glycopeptide antibiotic vancomycin. Using strain‐promoted azide‐alkyne cycloaddition, azide‐modified vancomycin is conjugated to selected staple strands and subsequently incorporated into 2D DON triangles. The resulting constructs show specific binding to the Gram‐positive species Bacillus subtilis (B. subtilis) and Staphylococcus capitis (S. capitis), and remarkably, to Gram‐negative Escherichia coli (E. coli), but no antimicrobial activity at vancomycin concentrations up to at least 2.91 μM. For B. subtilis and E. coli, DONs with vancomycin modifications on both sides exhibit better binding than DONs modified on only one side. However, both variants bind equally well to S. capitis. These results demonstrate the great potential of small molecule drug compounds for the robust, broad‐spectrum targeting of bacteria with DONs. Targeting a ubiquitous cell wall component of most pathogenic bacteria, vancomycin‐modified DONs have many potential applications in the prevention and treatment of nosocomial infections.}}, author = {{Coşkuner Leineweber, Özge and Pothineni, Bhanu K. and Schumann, Nils and Hofmann, Ulrike and Möser, Christin and Smith, David M. and Grundmeier, Guido and Zhang, Yixin and Keller, Adrian}}, issn = {{2688-4062}}, journal = {{Small Structures}}, publisher = {{Wiley}}, title = {{{Vancomycin‐Modified DNA Origami Nanostructures for Targeting Bacterial Pathogens}}}, doi = {{10.1002/sstr.202500246}}, year = {{2025}}, } @inbook{45827, author = {{Cao, Chuntian and Steinrück, Hans-Georg}}, booktitle = {{Reference Module in Chemistry, Molecular Sciences and Chemical Engineering}}, isbn = {{9780124095472}}, pages = {{391--416}}, publisher = {{Elsevier}}, title = {{{Molecular-scale synchrotron X-ray investigations of solid-liquid interfaces in lithium-ion batteries}}}, doi = {{10.1016/b978-0-323-85669-0.00105-7}}, year = {{2024}}, } @article{51121, abstract = {{DNA origami nanostructures are a powerful tool in biomedicine and can be used to combat drug‐resistant bacterial infections. However, the effect of unmodified DNA origami nanostructures on bacteria is yet to be elucidated. With the aim to obtain a better understanding of this phenomenon, the effect of three DNA origami shapes, i.e., DNA origami triangles, six‐helix bundles (6HBs), and 24‐helix bundles (24HBs), on the growth of Gram‐negative Escherichia coli and Gram‐positive Bacillus subtilis is investigated. These results reveal that while triangles and 24HBs can be used as a source of nutrients by E. coli and thereby promote population growth, their effect is much smaller than that of genomic single‐ and double‐stranded DNA. However, no effect on E. coli population growth is observed for the 6HBs. On the other hand, B. subtilis does not show any significant changes in population growth when cultured with the different DNA origami shapes or genomic DNA. The detailed effect of DNA origami nanostructures on bacterial growth thus depends on the competence signals and uptake mechanism of each bacterial species, as well as the DNA origami shape. This should be considered in the development of antimicrobial DNA origami nanostructures.}}, author = {{Garcia-Diosa, Jaime Andres and Grundmeier, Guido and Keller, Adrian}}, issn = {{1439-4227}}, journal = {{ChemBioChem}}, keywords = {{Organic Chemistry, Molecular Biology, Molecular Medicine, Biochemistry}}, publisher = {{Wiley}}, title = {{{Effect of DNA Origami Nanostructures on Bacterial Growth}}}, doi = {{10.1002/cbic.202400091}}, year = {{2024}}, }