The growing activity in the field of optical chemical sensors has resulted in numerous sensing schemes, new indicator
dyes, various polymeric matrix, size and shapes and highly diversified methods of immobilization. The sensor
characteristics are dependent upon the choice of indicator, polymer, immobilization technique, and also size. Sol-gel
technology provides a low-temperature method for obtaining porous silicate glass matrices. It enables to obtain material
in the form of films, powders, monoliths, fibres or nanoparticles. Organic reagents and molecular receptors can be easily
immobilized in the matrices. Moreover, one of the unique features of the sol-gel process is that the properties of the final
network structure, such as hydrophobicity, thickness, porosity, flexibility, reactivity and stability can be easily tailored
by controlling the process conditions, the type and the size of the precursors and catalysis. Here we will report about
several sensor designed over the years based on sol-gel materials for monitoring and controlling different parameters,
such as heavy metals, amines, phosphates, organophosphates.
|