Hybrid organic-inorganic sensors

Using the sol-gel process, it is possible to combine organic and inorganic components within the same matrix. Many new hybrid materials with unique mechanical, chemical or physical properties have been synthesized using this low-temperature, ‘soft chemistry’ route. Optics and sensing technology probably stand to benefit the most from the current research effort on these new materials. Since they combine the features of gel-derived oxides (mechanical strength, transparency in the visible, high porosity and surface area) with the characteristics of organic molecules (wide range of reactivity and specificity, optical properties), organic-inorganic hybrids are materials that often cannot be fabricated by other means. This report describes some recent work in the authorsʹ laboratory and briefly summarizes other recent advances in the field. According to a recent trend, it distinguishes between two different types of hybrids. In type I hybrids, the interaction between organic and inorganic constituents is weak and due to second order (Van der Waals or hydrogen) bonding. In Type II hybrids, the interaction between the organic and the inorganic constituents is strong and due to covalent or iono-covalent bonding.