The pivotal importance of TiO 2 as a technological material involves most applications in an aqueous environment, but the single‐crystal /bulk‐water interfaces are almost completely unexplored, since up to date solid/liquid more difficult access than surfaces ultrahigh vacuum (UHV). Only few techniques (as scanning probe microscopy) offer opportunity explore these systems under realistic conditions. rutile (110) surface immersed high‐purity water is studied by situ tunneling microscopy....

On-surface polymerization realized at the solid–liquid interface represents a promising route to obtain stable and conductive organic layers with tunable properties. We present here spectroscopic evidence of π-conjugated polymer formation between an iodine-modified Au(111) aqueous solution. Schiff-base coupling has been used drive reaction by changing pH. Scanning tunneling microscopy (STM) investigations show that substrate acts as template driving 1D ordered nanostructures. All chemical...

We have studied the controlled adsorption of molecules volatile compounds on thin Langmuir−Blodgett films porphyrins deposited onto surface a quartz microbalance. The modification film optical anisotropy has been measured by reflectance spectroscopy (RAS), and simultaneously, amount adsorbed monitored. Optical spectra after single analytes are interpreted straightforwardly in terms anisotropies related to H-like J-like aggregation modes porphyrins. By an appropriate selection analytes, we...

Using cyclic voltammetry (CV), reflectance anisotropy spectroscopy (RAS), and in situ electrochemical scanning tunneling microscopy (EC-STM), we have studied the structure structural transitions at a Cu(110) electrode surface 10 mM HCl solution as function of applied potential. While potentials lower than −550 mV vs Ag/AgCl STM images reveal adsorbate-free, unreconstructed surface, increasing potential ≥ chloride adsorption, indicated by CV, leads first to formation grooves followed growth...

The redox metalloprotein yeast cytochrome c was directly self-chemisorbed on "bare" gold electrodes through the free sulfur-containing group Cys102. Topological, spectroscopic, and electron transfer properties of immobilised molecules were investigated by in situ scanning probe microscopy cyclic voltammetry. Atomic force tunnelling revealed individual protein adsorbed substrate, with no evidence aggregates. proteins appear to be firmly bound display dimensions good agreement crystallographic...

In the past decade, there has been significant interest in integration of biomaterials with electronic elements: combining biological functions biomolecules nanotechnology offers new perspectives for implementation ultrasensitive hybrid nanodevices. particular, great attention devoted to redox metalloproteins, since they possess unique characteristics, such as electron-transfer capability, possibility gating activity, and nanometric size, which make them appealing bioelectronics applications...

Molecular recognition between two redox partners, azurin and cytochrome c 551, is studied at the single-molecule level by means of atomic force spectroscopy, after optimizing adsorption on gold via sulfhydryl-terminated alkanethiol spacers. Our experiments provide evidence specific interaction thereby demonstrating that preserves biorecognition capability when assembled these Additionally, measured kinetic reaction rate results are consistent with a likely transient nature complex....

A long-standing puzzle regarding the $\mathrm{Si}(111)\ensuremath{-}2\ifmmode\times\else\texttimes\fi{}1$ surface has been solved. The energy gap previously determined by photoemission on heavily $n$-doped crystals was not compatible with a strongly bound exciton known from other considerations to exist. New low-temperature angle-resolved and scanning tunneling microscopy data, together theory, unambiguously reveal that isomers opposite bucklings different gaps coexist such surfaces. subtle...

Porphyrins represent molecular building blocks for the development of a large variety functional materials. The control subtle intramolecular and intermolecular processes in solid porphyrin aggregates is promising establishment organic nanotechnology, which requires knowledge properties nanometric down to single atoms. Within this framework, optical anisotropy thin ultrathin metal-free tetraphenylporphyrin (H2TPP) films deposited on graphite carries interesting information related their...

Abstract We coupled protein–protein docking procedure with molecular dynamics (MD) simulation to investigate the electron transfer (ET) complex Azurin–Cytochrome c551 whose transient character makes difficult a direct experimental investigation. The ensemble of complexes generated by algorithm are filtered according both distance between metal ions in redox centres two proteins and involvement suitable residues at interface. resulting best (BC) is characterized 1.59 nm involves Val23 Ile59...

Various aspects of redox protein integration with nano-electronic elements are addressed by a multi-technique investigation different yeast cytochrome c (YCC)-based hybrid systems. Three immobilization strategies on gold via organic linkers explored, involving either covalent bonding or electrostatic interaction. Specifically, Au surfaces chemically modified self-assembled monolayers (SAMs) exposing thiol-reactive groups, acid-oxidized single-wall carbon nanotubes (SWNTs). Atomic force...

In this paper, we present results obtained by an optical technique, namely, reflectance anisotropy spectroscopy (RAS), applied to a series of GaAs1−xBix samples grown molecular beam epitaxy (MBE) under different strain conditions with the increasing concentration Bi, up higher value about 7%. The epitaxial buffer layers for growing layer were prepared either compressive (as it is commonly done) or tensile strain: latter case has been proven be strategy that allows us obtain better...

Many manifestations of natural processes give rise to interesting morphologies; it is all too easy cite the corrugation Earth's surface or planets in general. However, limiting ourselves 2D cases, morphology which crystal growth gives also intriguing. In particular, study some characteristics cluster projection 2D, namely shapes speckles (fractal dimension their rims) distribution areas. Recently, for instance, has been shown that size cumulative function (cdf) ``voids'' a corrole film on...

Abstract A mutant of copper plastocyanin, covalently bound to an Au (111) surface through engineered disulfide bridge, was investigated in aqueous medium by atomic force microscopy (AFM) and molecular dynamics (MD) simulations. Tapping‐mode AFM images revealed adsorption single molecules which are homogeneously distributed over the substrate strongly gold display uniform lateral size. statistical analysis height macromolecules on evidenced a distribution around mean value consistent with...

Despite the rising technological interest in use of calcium-modified TiO2 surfaces biomedical implants, Ca/TiO2 interface has not been studied an aqueous environment. This investigation is first report on situ scanning tunneling microscopy (STM) to study rutile TiO2(110) immersed high purity water. The surface was prepared under ultrahigh vacuum (UHV) with repeated sputtering/annealing cycles. Low energy electron diffraction (LEED) analysis shows a pattern typical for segregation calcium,...

Energy levels of the complexes formed by Ga vacancies binding one or more deuterium (or hydrogen) atoms are investigated low-temperature photoluminescence. Since as-grown, nondeuterated material is unintentionally doped p type, emission possible because ‘‘internal’’ recombination from a D donor in an adjacent bond-center position and ground different vacancy configurations, with zero, one, trapped its dangling bonds. At 2 K, transitions occur at 1.14, 1.19–1.22, 1.33–1.30, 1.34 eV, last two...

The tunneling mechanism of electrons and holes to surface states from near-surface Al0.3Ga0.7As/GaAs quantum wells has been investigated by steady-state time-resolved photoluminescence spectroscopy, near liquid-helium temperature, the excitonic e1-hh1 transition in well. ensemble data, taken over a wide range optical excitation levels, for various values tunneling-barrier thickness, before after passivation hydrogen, allows description both details character behavior relevant states. main...

Optical experiments on the $\text{Si}(111)\text{\ensuremath{-}}2\ifmmode\times\else\texttimes\fi{}1$ surface show that absorption peak due to dangling-bond transitions exhibits a blueshift upon oxygen exposure. The effect is interpreted as quantum confinement of electrons in $\ensuremath{\pi}$-bonded chains atoms, whose length decreases with uptake (a particle-in-a-box effect, box being one dimensional). This conclusion supported by numerical simulation optical spectra.

Reflectance anisotropy spectroscopy (RAS) has been largely used to investigate organic compounds: Langmuir-Blodgett and Langmuir-Schaeffer layers, the molecular beam epitaxy growth in situ real time, thin ultrathin films exposed volatiles, ultra-high vacuum (UHV), controlled atmosphere even liquid. In all these cases, porphyrins porphyrin-related compounds have often used, taking advantage of peculiar characteristics RAS with respect other techniques. The technical modification a...

Domains of different surface reconstruction-negatively or positively buckled isomers-have been previously observed on highly n-doped Si(111)-2 × 1 surfaces by angle-resolved ultraviolet photoemission spectroscopy and scanning tunneling microscopy/spectroscopy. At low temperature, separate domains the two isomer types are apparent in data. It was argued previous work that negative isomers have a lower energy their empty states than positive isomers, providing driving force for formation...

Corrole derivatives have been recently employed in many applications at the solid-liquid interface. Therefore, structural arrangement of molecular layers direct contact with liquid is fundamental interest. We investigated solution deposition previously prepared water-soluble phosphorus complex a 2-sulfonato-10-(4-sulfonatophenyl)-5,15-dimesitylcorrole [see synthesis our previous paper, M. Naitana et al., Chem. Eur. J. 2017, 23, 905-916]. The layer formation P corroles onto Au(111) surface...

The degree of 1D character surface chains at group IV (111)-2 × 1 reconstructed surfaces is established by sensitive optical spectroscopy. Optical experiments on a diamond C(111)-2 show that the absorption peak related to dangling-bond transitions exhibits marked blueshift upon oxygen exposure clean surface. Such behaviour analogous observed Si(111)-2 For both experimental finding interpreted in terms quantum confinement electrons quasi-one-dimensional π-bonded chains, whose length decreases...

Lattice-matched ZnSe/InxGa1−xAs heterostructures were fabricated by molecular beam epitaxy on GaAs(001)2×4 surfaces. We find that the partial character of strain relaxation within ternary layer can be compensated a suitable excess in In concentration to match free-surface lattice parameter ZnSe. The surface II–VI epilayer, however, exhibits cross-hatched pattern corrugations oriented along orthogonal 〈110〉 directions. This complex morphology reflects formation slip steps during nucleation...