Entrapment of biomolecules in sol-gel matrix for applications in biosensors: problems and future prospects

An emerging area that has attracted increased attention in recent years is the development of biosensors based on sol-gel-derived platforms which must be predicated on an understanding of the short and long-term interactions between the biorecognition elements and evolving sol-gel matrix. This review focuses on the growing field of entrapment of biomolecules such as proteins, enzymes and antibodies in sol-gel matrices prepared from alkoxide precursors. Basic aspects of sol-gel, its advantages and disadvantages, factor affecting the sol-gel-derived thin films, strategies for improving entrapment of biomolecules in sol-gel materials and their organic modifications are discussed. Organically modified silane precursors have the ability to tune physical and chemical properties with desired characteristics of sol-gel preparations by simply changing different precursors and their molar ratio. The usefulness of optical method especially time-resolved fluorescence spectroscopy for the characterization of internal environment of sol-gel as well as dynamics of proteins within the sol-gel is highlighted. Significance and designing of new biocompatible sol-gel precursors with the purpose of making the glassy matrix more compatible with entrapped biomolecules has been described. Considerable attention has been drawn on problems and future prospects of sol-gel matrix for entrapment of biomolecules for applications in biosensors.