Photoactive nanostructured hybrid materials for optical and biomedical applications

Abstract

Along this manuscript different hybrid materials are synthesized and extensively characterized for several used: from optical to therapeutic applications. First, by the incorporation of different dyes, styryl 722 and pyronine into several smectite clay films, macroscopically ordered systems are obtained. The effect of the clay on the dye is deeply analysed and its preferential orientation is studies by anisotropic response of the films to the linear polarized light. Second, large monoliths with embedded laser dyes with strong absorption and fluorescence bands in different region of the visible spectrum are attained by sol gel chemistry to obtain solid-state dye laser (SSDL) with good photo, thermal and chemical stabilities. Third, silica NP (NP) with suitable size (50 nm) and functionalized external surface are also synthesized by sol gel chemistry. Through the encapsulation of fluorescent dye molecules in their core and by the grafting of the photosensitizers on their shell, biocompatible nanoparticles for bio-imaging and photodynamic therapy (PDT) applications are prepared. In order to optimize their properties, a careful investigation of the photophysical properties and mainly the singlet oxygen generation of a large range of new photosensitizer based on chromophores known as BODIPYs, is previously carried out. Based on the results, some efficient BODIPYs are selected for grafting on silica nanoparticles in order to use them for PDT.