Adsorption of Modified Arg, Lys, Asp, and Gln to Dry and Hydrated ZnO Surface: A Density Functional Theory Study

Energy Landscape of Relaxation and Interaction of an Amino Acid, Glutamine (L), on Pristine and Au/Ag/Cu-Doped TiO2 Surfaces

Studying the interaction of inorganic systems with organic ones is a highly important avenue for finding new drugs and treatment methods. Tumor cells show an increased demand for amino acids due to their rapid proliferation; thus, targeting their metabolism is becoming a potential oncological therapeutic strategy. One of the inorganic materials that show antitumor properties is titanium dioxide, while its doping was found to enhance interactions with biological systems. Thus, in this study, we investigated the energy landscape of glutamine (L), an amino acid, on pristine and doped TiO2 surfaces. We first locally optimized 2D-slab structures of pristine and Au/Ag/Cu-doped anatase (001 and 101 surfaces) and similarly optimized a single molecule of glutamine in vacuum. Next, we placed the pre-optimized glutamine molecule in various orientations and on a variety of locations onto the relaxed substrate surfaces (in vacuum) and performed ab initio relaxations of the molecule on the substrate slabs. We employed the DFT method with a GGA-PBE functional implemented in the Quantum Espresso code. Comparisons of the optimized conformations and electronic structures of the amino acid in vacuum and on the surfaces yield useful insights into various biological processes.

Interactions between Metal Oxides and Biomolecules: from Fundamental Understanding to Applications

Metallo-oxide (MO)-based bioinorganic nanocomposites promise unique structures, physicochemical properties, and novel biochemical functionalities, and within the past decade, investment in research on materials such as ZnO, TiO₂, SiO₂, and GeO₂ has significantly increased. Besides traditional approaches, the synthesis, shaping, structural patterning, and postprocessing chemical functionalization of the materials surface is inspired by strategies which mimic processes in nature. Would such materials deliver new technologies? Answering this question requires the merging of historical knowledge and current research from different fields of science. Practically, we need an effective defragmentation of the research area. From our perspective, the superficial accounting of material properties, chemistry of the surfaces, and the behavior of biomolecules next to such surfaces is a problem. This is particularly of concern when we wish to bridge between technologies in vitro and biotechnologies in vivo. Further, besides the potential practical technological efficiency and advantages such materials might exhibit, we have to consider the wider long-term implications of material stability and toxicity. In this contribution, we present a critical review of recent advances in the chemistry and engineering of MO-based biocomposites, highlighting the role of interactions at the interface and the techniques by which these can be studied. At the end of the article, we outline the challenges which hamper progress in research and extrapolate to developing and promising directions including additive manufacturing and synthetic biology that could benefit from molecular level understanding of interactions occurring between inanimate (abiotic) and living (biotic) materials.

Borophene as a promising anode material for sodium-ion batteries with high capacity and high rate capability using DFT

Two-dimensional boron synthesized by the chemical vapor deposition method is an atomically thin layer of boron with both light weight and metallicity. To investigate the potential of borophene as an anode material in sodium-ion batteries, first-principles calculations and ab initio molecular dynamics simulations were carried out. The calculated results reveal that after introducing vacancy defects, the special puckered structure becomes relatively flat and the metallic nature of the defective borophene is enhanced, while the defects in borophene can weaken sodium adsorption. A single sodium atom is preferentially absorbed on the B_V site. The adsorption energies gradually reduce with an increase in sodium concentration due to the increased Na–Na repulsion. The fully sodium storage phase of borophene corresponds to NaB₂ with a theoretical specific capacity of 1240 mA h g⁻¹, which is much larger than that of other two-dimensional materials. Most interestingly, sodium ion flows in the furrows of puckered borophene are extremely fast with a low energy barrier of 30 meV. Meanwhile, sodium diffusion on borophene was found to be highly anisotropic, as further verified by the results of the ab initio molecular dynamics simulations. The sodiated-borophene nanostructure shows enhanced electronic conductivity during the whole sodiation process, which is superior to other anode materials. Borophene is expected to be a promising candidate with high capacity and high rate capability for anode materials in sodium-ion batteries.

Two-dimensional boron synthesized by the chemical vapor deposition method is an atomically thin layer of boron with both light weight and metallicity.

Comparative density functional theory and density functional tight binding study of arginine and arginine-rich cell penetrating peptide TAT adsorption on anatase TiO2

A comparative DFT-DFTB study of geometries and electronic structures of arginine, arginine dipeptide, and arginine-rich cell penetrating peptide TAT on the surface of TiO₂.