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Thermal and EPR Study of DNA–Based Membranes
A. Firmino, I. D. A. Silva, S. Claro Neto, C. J. Magon, J. P. Donoso, F. Kajzar, J. Kanicki and A. Pawlicka

The present paper focuses on the results obtained from impedance spectroscopy, thermal analysis (DSC and DMA) and electron paramagnetic resonance (EPR) of membranes of DNA plasticized with glycerol and containing either poly(ethylene dioxythiophene) (PEDOT) or Prussian Blue (PB) and copper perchlorate (CuClO4). The ionic conductivity values for the DNAPEDOT- CuClO4 and DNA-PB-CuClO4 of 4.8×10-4 S/cm and 2.2×10-4 S/cm at 30 oC, respectively, were obtained. The DSC analysis of the samples showed two glass transition temperatures at about -80 and 50 °C and DMA a permanent deformation above 50 °C ascribed to a transition between elastic and plastic states. The EPR spectra evidenced that Cu2+ ions are in tetragonally distorted octahedral sites and the quantitative analysis of the EPR spin Hamiltonian g|| and A|| parameters revealed copper ions complexed by nitrogen and oxygen atoms. All these results suggest that DNA-biomembranes are interesting materials to be used in materials engineering science.

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