Elucidating the underlying principles behind band gap engineering is paramount for the successful implementation of semiconductors in photonic and optoelectronic devices. Recently it has been shown that the band gap of a wide and direct band gap semiconductor, such as ZnO, can be modified upon co-crystallization with amino acids, with the role of the biomolecules remaining unclear. Here, by probing and modeling the light emitting properties of ZnO-amino acid co-crystals, we identify the amino acids role on this band gap modulation and demonstrate their effective chirality transfer to the inter-band excitations in ZnO. Our 3D quantum model suggests that the strong band edge emission blue shift in the co-crystals can be explained by a quasi-periodic distribution of amino acid potential barriers within the ZnO crystal lattice. Overall, our findings indicate that biomolecule co-crystallization can be used as a truly bio-inspired means to induce chiral quantum confinement effects in quasi-bulk semiconductors.
During a bioInspired crystallization process, incorporation of amino acids into the crystal structure of ZnO induces lattice strain that leads to linear bandgap shifts.
In this work, experimental and data analysis procedures were developed and applied for studying amino acid crystals by means of X-ray phase measurements. It clearly demonstrated the sensitivity of invariant triplet phases to electronic charge distribution in D-alanine crystal, providing useful information on intermolecular forces for molecular dynamics calculations. Feasibility of phase measurements to investigate radiation damage mechanisms is also discussed on experimental and theoretical grounds.
The focus of this article is based on the aqueous dispersed state properties of inorganic ZnO nanoparticles (average size lessthan or equal to 4 nm), their surface modification and bio-functionalization with folic acid at physiological pH ~ 7.5, suitable for bio-imaging and targeted therapeutic application. While TEM studies of the ZnO nano-crystallites have been performed to estimate their size and morphology in dry state, the band gap properties of the freshly prepared samples, the hydrodynamic size in aqueous solution phase and the wide fluorescence range in visible region have been investi…
We studied the electronic and the structural properties of amino acids (alanine, glycine, and histidine) attached to graphene oxide (GO) by peptide bonding, via plane wave pseudopotential total-energy calculations within the local spin density approximation (LSDA). The HOMO-LUMO gap, the Hirshfeld charges, and the equilibrium geometrical structures exhibit keen variations depending on the species of the attached amino acid. The GO-amino acid system appears to be a good candidate as a biosensor.
In this paper we present a framework for fast quantum conductance calculations of carbon nanotube-based sensing devices targeting aromatic amino acids within a tight binding approximation. The method begins by a novel parameterization procedure based on isospectral matrix flows. With the properly parameterized Hamiltonian we employ a linearly scaling algorithm to compute the quantum conductance in the coherent transport regime. A few conclusions are presented regarding the suitability of carbon nanotubes in aromatic amino acid detection.
Incorporation of organic molecules into the lattice of inorganic crystalline hosts is a common phenomenon in biomineralization, and has been shown to alter various properties of the crystalline host. Taking this phenomenon as our source of inspiration, we show herein that incorporation of specific single amino acids into the lattice of manganese (II) carbonate strongly alters its inherent magnetic properties. At room temperature, the magnetic susceptibility of the amino-acid-incorporating paramagnetic MnCO3 decreases, following a simple rule of mixtures. When cooled below the Néel temperature,…
Amino acids are essential to all life. However, our understanding of some aspects of their intrinsic structure, molecular chemistry, and electronic structure is still limited. In particular the nature of amino acids in their crystalline form, often essential to biological and medical processes, faces a lack of knowledge both from experimental and theoretical approaches. An important experimental technique that has provided a multitude of crucial insights into the chemistry and electronic structure of materials is X-ray photoelectron spectroscopy. Whilst the interpretation of spectra of simple …
In interfaces between inorganic and biological materials relevant for technological applications, the general challenge of structure determination is exacerbated by the high flexibility of bioorganic components, chemical bonding, and charge rearrangement at the interface. In this paper, we investigate a chemically complex building block, namely, the arginine (Arg) amino-acid interfaced with Cu, Ag and Au (111) surfaces. We investigate how the environment changes the accessible conformational space of this amino acid, by building and analyzing a database of thousands of structures optimized wit…
Composite hybrid gold crystals are of profound interest in various research areas ranging from materials science to biology. Their importance is due to their unique properties and potential implementation, for example in sensing or in bio-nanomedicine. Here we report on the formation of hybrid organic-metal composites via the incorporation of selected amino acids histidine, aspartic acid, serine, glutamine, alanine, cysteine, and selenocystine into the crystal lattice of single crystals of gold. We used electron microscopy, chemical analysis and high-resolution synchrotron powder X ray diffrac…
Ionic liquids (ILs) constitute one of the most active fields of research nowadays. Many organic and inorganic molecules can be converted into ions via relatively simple procedures. These ions can be combined into ILs. Amino acid based ILs (AAILs) represent a specific interest due to solubilization of biological species, participation in enzymatic catalysis, and capturing toxic gases. We develop a new force field (FF) for the seven selected AAILs comprising 1-ethyl-3-methylimidazolium cation and amino acid anions with polar residues. The anions were obtained via deprotonation of carboxyl group.…
Impacts by small solar system bodies (meteoroids, asteroids, comets and transitional objects) are characterized by a combination of energy dynamics and chemical modification on both terrestrial and small solar system bodies. In this context, the discovery of glycine amino acid in meteorites and comets has led to a hypothesis that impacts by astronomical bodies could contribute to delivery and polymerization of amino acids in the early Earth to generate proteins as essential molecules for life. Besides the possibility of abiotic polymerization of glycine, its decomposition by impacts could gene…
