Composite Silica-Based Films as Platforms for Electrochemical Sensors

Sol-gel-derived silica thin films generated onto electrode surfaces in the form of organic-inorganic hybrid coatings or other composite layers have found tremendous interest for being used as platforms for the development of electrochemical sensors and biosensors. After a brief description of the strategies applied to prepare such materials, and their interest as electrode modifier, this review will summarize the major advances made so far with composite silica-based films in electroanalysis. It will primarily focus on electrochemical sensors involving both non-ordered composite films and vertically oriented mesoporous membranes, the biosensors exploiting the concept of sol-gel bioencapsulation on electrode, the spectroelectrochemical sensors, and some others. Electrodes modified with silica-based composite films prepared from evaporation or electrochemical methods and comprising selected modifiers (organic reagents, metal-ligand complexes, macromolecules, biological materials, nanoparticles) are attractive for applications as recognition elements of the electrochemical sensors and biosensors. Recent advances in this field are discussed in the review.image