Supports and Matrices

Reagents and indicators are immobilized, occluded or dissolved in supports which are formed by cross-linked polymers, plasticized polymers or organic and inorganic activated surfaces. The waveguide itself, the cladding of an optical fiber or any other optical element can be the support. However, it must obey two basic functions act as a liquid-solid or gas-solid interface and, if radiation crosses through it to allow the signal transmission, be an optically transparent material. 

On the other hand, it must stay inert while facing the chemical reactions that are involved in the recognizing process and it must assure an efficient radiation coupling with the light source, if optical fibers are used. In addition, the matrix sometimes plays the role to improve selectivity and regulates the charge transference. 

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