Bioequivalent UV detectors based on cholesteric liquid crystals: effects of spectral composition and quantitative account for intensity of UV radiation

摘要

Response of cholesteric sensor materials to biologically active UV radiation has been studied. The sensor mixture comprised a cholesteric liquid crystalline matrix doped with provitamin D, and changes in the maximum selective reflection wavelength λ_(max) caused by the photochemical reaction of provitamin D → vitamin D transformation were recorded. Using a UV source (DRT-240 lamp) calibrated accounting for the specific irradiation geometry, λ_(max) shifts were obtained as function of UV illuminance dose (in J/cm~2). Using a set of optical filters cutting off specified parts of the provitamin D absorption spectrum, effects of the spectral composition of UV radiation upon the response characteristics of sensor were determined. The results obtained support our earlier considerations of the developed sensor material as "bioequivalent".