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Graphene Oxide (GO) has been shown to exhibit properties that are useful in applications such as biomedical imaging, biological sensors, and drug delivery. The binding properties of biomolecules at the surface of GO can provide insight into the potential biocompatibility of GO. Here we assess the intrinsic affinity of amino acids to GO by simulating their adsorption onto a GO surface. The simulation is done using Amber03 force-field molecular dynamics in explicit water. The emphasis is placed on developing an atomic charge model for GO. The adsorption energies are computed using atomic charges obtained from an ab initio electrostatic potential based method. The charges reported here are suitable for simulating peptide adsorption to GO. [ABSTRACT FROM AUTHOR]

Several nondestructive characterization techniques (optical and photothermal deflection spectroscopy in the visible photon energy range, Raman spectroscopy, profilometry, photoluminescence, electron-spin-resonance characterization of the paramagnetic centers, etc.) are used to study the properties of the a-C:H:OH films deposited by the ''dip'' technique. With such a preparation method, the substrates are dipped in viscous mixtures of liquid carbon compounds. The subsequent baking in an oven at different temperatures (300-500°C) allows the formation on a substrate of submicrometric thin solid films. The as-prepared material exhibits several characteristics that are comparable to that of floppy, polymer-like amorphous carbons. Transitions on many film properties thicknesses, optical gaps, photoluminescence intensities, spin densities, g factors, relaxation times, etc. were found between 300 and 350 and between 450 and 500°C. [ABSTRACT FROM AUTHOR]

The present study is focused on the vibrational and structural characterization of a set of disordered hydrogenated carbon nitride (a-CN:H) thin films grown by reactive sputtering. A comparative analysis of the experimental results as achieved by Raman and infrared (IR) spectroscopies is made. The disorder-induced features of IR and Raman spectra are discussed as well in light of the current assessment on the vibrational properties of carbon-based materials. Some differences between a-CN:H and nonnitrogenated a-C:H materials are evidenced and attributed to the effects of charge redistribution and bond polarization due to the presence of nitrogen. In order to justify such a hypothesis, the dielectric constant, the dynamic effective charge, and the IR cross section determined by the charge transfer effects are calculated and found to be in agreement with the corresponding experimental values. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The properties of the a-C: H:OH films deposited by the 'dip' technique are studied by several nondestructive characterization techniques (optical and photothermal deflection spectroscopy in the visible photon energy range, Raman spectroscopy, profilometry, photoluminescence, electron-spin-resonance characterization of the paramagnetic centers). The as-prepared material exhibits several characteristics comparable to those floppy, polymer-like amorphous carbons.