Raman and Fluorescence Imaging of Polyoxometalate Composite Agarose Films

Composite agarose films were prepared with Eu-III containing polyoxometalates, in particular the organic-inorganic hybrid [Eu(W5O18)(2)(pic)(4)](13-) (Hpic = 3-hydroxypicolinic acid) and a Mo blue Eu-III derivative. The latter compound shows interesting Eu-III based photoluminescence properties, described for a molybdenum blue compound for the first time. Imaging of optical properties and morphology of the films was explored by Raman and fluorescence measurements in a confocal microscopy system, together with the AFM profile. Raman and fluorescence imaging are powerful tools for the characterization of the films, in particular their chemical composition and homogeneity at the micrometric scale.