Provitamin D Doped Silica and Polymeric Films: New Materials for UV Biosensor –Oct 2010
TN Orlova, IP Terenetskaya, AM Eremenko, N. I. Surovtseva2 Institute of Physics and Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine
The original technologies of growing silica films, impregnated with 7-dehydrocholesterol (provitamin D3) on quartz substrates and free transparent films on the basis of polyvinyl alcohol and polyvinyl butyral have been developed. Provitamin D photoisomerization in the films under UVB irradiation was investigated by UV absorption spectroscopy. Remarkable changes in the absorption spectrum of 7-DHC were observed in silica and polyvinyl alcohol films as compared with ethanol solution, only in polyvinyl butyral film the spectrum was very nearly, while the spectral kinetics of 7-DHC photoisomerization in all the films was different from ethanol. We suggest that several films have potential as UV dosimeters to measure accumulated ‘antirachitic’ UV dose in the same manner as erythemic UV dose is measured by commonly used polysulphone film. Spectral irradiance of the UV lamp at the sample distance 8 cm was determined using calibrated spectrometer BLACK-Comet (StellarNet, Inc).
Figure- Transformation of the 7-DHC absorption spectrum in ethanol (a), PVB film (b), silica film (c) and PVA film (d) upon irradiation with the EL-30 UV lamp.
