@article{DaiMateGlebeetal.2018, author = {Dai, Xiaolin and Mate, Diana M. and Glebe, Ulrich and Garakani, Tayebeh Mirzaei and K{\"o}rner, Andrea and Schwaneberg, Ulrich and B{\"o}ker, Alexander}, title = {Sortase-mediated ligation of purely artificial building blocks}, series = {Polymers}, volume = {10}, journal = {Polymers}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2073-4360}, doi = {10.3390/polym10020151}, pages = {13}, year = {2018}, abstract = {Sortase A (SrtA) from Staphylococcus aureus has been often used for ligating a protein with other natural or synthetic compounds in recent years. Here we show that SrtA-mediated ligation (SML) is universally applicable for the linkage of two purely artificial building blocks. Silica nanoparticles (NPs), poly(ethylene glycol) and poly(N-isopropyl acrylamide) are chosen as synthetic building blocks. As a proof of concept, NP-polymer, NP-NP, and polymer-polymer structures are formed by SrtA catalysis. Therefore, the building blocks are equipped with the recognition sequence needed for SrtA reaction-the conserved peptide LPETG-and a pentaglycine motif. The successful formation of the reaction products is shown by means of transmission electron microscopy (TEM), matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-ToF MS), and dynamic light scattering (DLS). The sortase catalyzed linkage of artificial building blocks sets the stage for the development of a new approach to link synthetic structures in cases where their synthesis by established chemical methods is complicated.}, language = {en} } @article{HollandMoritzGraupnerMoelleretal.2018, author = {Holland-Moritz, Henry and Graupner, Julia and M{\"o}ller, Wolfhard and Pacholski, Claudia and Ronning, Carsten}, title = {Dynamics of nanoparticle morphology under low energy ion irradiation}, series = {Nanotechnology}, volume = {29}, journal = {Nanotechnology}, number = {31}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0957-4484}, doi = {10.1088/1361-6528/aac36c}, pages = {7}, year = {2018}, abstract = {If nanostructures are irradiated with energetic ions, the mechanism of sputtering becomes important when the ion range matches about the size of the nanoparticle. Gold nanoparticles with diameters of similar to 50 nm on top of silicon substrates with a native oxide layer were irradiated by gallium ions with energies ranging from 1 to 30 keV in a focused ion beam system. High resolution in situ scanning electron microscopy imaging permits detailed insights in the dynamics of the morphology change and sputter yield. Compared to bulk-like structures or thin films, a pronounced shaping and enhanced sputtering in the nanostructures occurs, which enables a specific shaping of these structures using ion beams. This effect depends on the ratio of nanoparticle size and ion energy. In the investigated energy regime, the sputter yield increases at increasing ion energy and shows a distinct dependence on the nanoparticle size. The experimental findings are directly compared to Monte Carlo simulations obtained from iradina and TRI3DYN, where the latter takes into account dynamic morphological and compositional changes of the target.}, language = {en} }