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A thermo chemical method for the synthesis of layered composites of graphite-like carbon nitride from urea and melamine has been developed. The production of graphite-like carbon nitride has been proven, SEM, X-ray diffraction, Raman spectroscopy and elemental analysis. Electrochemical studies have established that the obtained composites are promising materials as metal-free catalysts for oxygen electrodes for fuel cells.

DNA conformational changes caused by gold and colloidal gold surface have been studied by surface enhanced infrared spectroscopy (SEIRA), spectroscopy of plasmon resonance (SPR), atomic force microscopy (AFM) and principal component analysis. Experimental data have shown that DNA conformation is slightly influenced by gold surface, while it is strongly altered by colloidal gold. Spectroscopic features of DNA-colloidal gold system have shown that the intensity of the asymmetric PO 2 band at 1240 cm 1 decreases by two times, and that of symmetric band at 1090 cm 1 decreases by 2.4 times whereas the halfwidth of phosphate bands increases by 3540 cm 1 ; a frequency shift of asymmetric band position from 1240 to 1246 cm 1 and a symmetric band from 1090 to 1106 cm 1 has been observed. It was shown that intensity variation and shift of DNA base vibrations together with the broadening of OH, NH, and CH stretching vibrations occur due to DNA conformational changes and the redistribution of the H-bonding network. A supposition about DNA condensation by colloidal gold was made. SEIRA and AFM data have showed major DNA structural changes occurred on gold colloidal particles. It was found that all the spectral features are more prominent for DNAcolloidal gold system deposited on gold substrate than on CaF 2 substrate.

Abstract. New approach for optical imaging, structural study and cell cultivation based on the effect of the enhancement of optical signals from biomolecules and biological cells near nanostructured rough gold surface is proposed. The surface enhanced IR absorption (SEIRA) spectroscopy and confocal microscopy experiments were made using the culture of SPEV (porcine embryonic kidney epithelium transplantable line) and fibroblast cells, cultivated and/or adsorbed on the gold substrate. The SEIRA spectra registered from monolayer of the SPEV cells cultivated on the rough gold showed a low frequency shift of about 2 to 7 cm -1 for the most characteristic IR vibrations, compared with those adsorbed from suspension on the same substrate. An enhancement factor of 15…30 was obtained for different molecular vibrations. The confocal microscopy contrast images of the SPEV cells on rough gold substrate were obtained in laser fluorescence mode. This approach opens new possibilities for visualization of the living cells in vivo without staining. The fluorescence of the rough gold surfaces and effects responsible for our findings have been discussed.