A one-step protocol for interfacial self-assembly of graphene oxide (GO), glutamine-substituted perylene diimide (PDI-glu), 10,12-pentacosadiynoic acid (PCDA), and zinc acetate into three-and four-component hybrid nanofilms through hydrogen and coordination bonding was developed. The hybrids deposited onto solid supports were studied after polymerization of PCDA by UV−vis absorption, fluorescence, and Raman spectroscopies, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results of spectroscopic studies suggest that the hybrids assembled through H-bonds can maintain the light-induced Forster energy transfer from the PDI-glu chromophore to the conjugated polymer and then to GO leading to fluorescence quenching. In the hybrids assembled through coordination bonding with zinc clusters, the energy transfer proceeds from PDI-glu to the PDA polymer, whereas the transfer from PDA to GO is quenched completely. Another important characteristic of these ultrathin hybrids is their stability with respect to photobleaching of chromophores due to the acceptor properties of GO. The as-assembled hybrid nanofilms were integrated with conventional photovoltaic planar architectures to study their photoelectric properties. The zinc-containing hybrids integrated with a hole transport layer exhibited photovoltaic properties. The cell with the integrated four-component hybrid comprising both PDI-glu and PDA showed a photocurrent/dark current ratio almost an order higher than that of the three-component hybrid assembled with PDA only. The supramolecular method based on the interfacial selfassembly can be extended to a wide variety of organic chromophores and polymerizable surfactants for integrating them into multicomponent functional GO-based nanohybrids with targeted properties for organic electronics.

No abstract

No abstract

Confocal laser endomicroscopy (CLE) is a method of optic biopsy, which allows obtaining histologic presentation of mucous tunic in real time IntroductionDetailed visualization of the digestive tract's mucous tunic is necessary for early diagnostics of a disease. Probe-based confocal laser endomicroscopy (pCLE) is a new method of gastrointestinal endoscopy, which yields images of mucous tunic of ca. 1 micron resolution and visualizes cellular and subcellular structures, capillaries and singular blood cells. The available published data indicate high interconnection of confocal endomicroscopy intravital images with the traditional histology of the unaltered digestive tract's mucous tunic [1,2]. The technique allows quickly differentiating between an inflamed, metaplastic or dysplastic mucous tunic; without any doubt, this increases interest in the use of this technique in clinical practice for diagnosis of such diseases as Barrett esophagus, gastric metaplasia of esophagus, neoplasms, inflammatory diseases of large and small intestines, Helicobacter pylori, celiac disease etc. It should be noted, that it is necessary to administer a diagnostic agent intravenously in order to obtain high-contrast images at pCLE of digestive tract. 10% sodium fluorescein solution may be used; it is widely applied in diagnostic practice in adult patients [2,3]. In 2008, the Ministry of Health of the RF approved intravenous fluorescein administration for evaluation of eye fundus condition using a confocal laser ophthalmoscope (Registration number LRS-000829/08 of 18.02.08); the procedure itself appeared to be of excellent safety level in pediatric ophthalmology [3]. This study is relevant due to the lack of direct indication in the world pediatric practice to intravenous administration of this pCLE-required diagnostic agent.

The results of studies of the influence of the thicknesses of the electron-blocking, hole-conducting and recombination layers on the luminance-voltage and other electrophysical characteristics of a multilayer light-emitting diode with an active layer based on semiconductor quantum dots are presented. Optimized thicknesses and voltages are determined to achieve the maximum efficiency of electroluminescence of the light-emitting diode. Keywords: quantum dots, light-emitting diode, blocking layer.