The receptor binding domain (RBD) of spike proteins plays a crucial role in the process of severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) attachment to the human angiotensin-converting enzyme 2 (ACE2). The N501Y mutation and later mutations introduced extra positive charges on the spike RBD and resulted in higher transmissibility, likely due to stronger binding with the highly negatively charged ACE2. Consequently, many studies have been devoted to understanding the molecular mechanism of spike protein binding with the ACE2 receptor.
View Article and Find Full Text PDFThe structure of the prototypical acrylic polymer (poly(methyl methacrylate): PMMA)/water interface is elucidated at the molecular level using heterodyne-detected sum-frequency generation. Two distinct OH groups of interfacial water are found at the interface: one forms hydrogen bonds with the carbonyl group and the other weakly interacts with the ester methyl group of the polymer surface.
View Article and Find Full Text PDFDespite recent significant advances in interface-selective nonlinear spectroscopy, the topmost water structure at a charged silica surface is still not clearly understood. This is because, for charged interfaces, not only interfacial molecules at the topmost layer but also a large number of molecules in the electric double layer are probed even with second-order nonlinear spectroscopy. In the present study, we studied water structure at the negatively charged silica/aqueous interface at pH 12 using heterodyne-detected vibrational sum frequency generation spectroscopy, and demonstrated that the spectral component of the topmost water can be extracted by examining the ionic strength dependence of the Imχ spectrum.
View Article and Find Full Text PDFThe diameter dependence of the optical band gap of single CdSe nanowires (NWs) is investigated by a combination of atomic force microscopy, scanning fluorescence microscopy, and transmission electron microscopy. We find a good congruence of the experimental data to calculations within the effective mass approximation taking into account quantization, exciton Coulomb interaction, and dielectric mismatch. The experimental data are furthermore compared to different theoretical approaches.
View Article and Find Full Text PDFCdSe clusters react with liquid Bi- nanocatalysts to form one-dimensional CdSe nanowires in solution. The use of cluster precursors as compared to molecular precursors leads to a high local CdSe concentration, which favors the growth of nanowires with thin diameters and a narrow diameter distribution.
View Article and Find Full Text PDFWe synthesized monodisperse cobalt-platinum nanoparticles Co(0.14-0.22)Pt(0.
View Article and Find Full Text PDFThe formation of monodisperse, tunable sized, alloyed nanoparticles of Ni, Co, or Fe with Pt and pure Pt nanoparticles attached to carbon nanotubes has been investigated. Following homogeneous nucleation, nanoparticles attach directly to nonfunctionalized single-walled and multi-walled carbon nanotubes during nanoparticle synthesis as a function of ligand nature and the nanoparticle work function. These ligands not only provide a way to tune the chemical composition, size, and shape of the nanoparticles but also control a strong reversible interaction with carbon nanotubes and permit controlling the nanoparticle coverage.
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