Optical sensor coating development for industrial applications

Abstract

Optical sensors are important for in situ and ex situ monitoring in industrial processes and environmental control. The development of these tools involves the immobilization of a sensitive element within a matrix. Therefore, the sol-gel process represents a powerful strategy for developing and improving optical sensors, especially those for coating applications. This approach allows the use of several strategies in terms of different synthetic routes and the production of hybrid matrices, which can help to produce highly specific sensors and solve problems such as receptor element leaching. Controlling the textural characteristics allows for tuning of the matrix permeability of analytes to the receptor element without leaching from the network or affecting the receptor identity or functionality. The introduction of organic moieties appears to be a good alternative for providing systems with differentiated characteristics (i.e., performance). Here, recent results describing sol-gel hybrid optical coating sensors are reviewed to demonstrate their state-of-the-art industrial applications for gases, pH, solvents, and ionic species monitoring.