Supramolecular Gel-Based Materials for Sensing Environmentally Sensitive Molecules

Supramolecular gels are at the cutting edge of material science. The interactions which constitute the solid-like network are non-covalent interactions like hydrogen bonds, van der Waals forces, π–π stacking, dipole–dipole, and coordination interactions. The integrant includes small molecules which assemble into the polymeric framework. These "paramount gels" with diversity in their structure exhibit manifold applications. Also, the possibility of manipulating the gel with entities sensitive to external light or chemical molecules makes them good candidate materials for sensing applications. The weak non-covalent reversible interactions contribute to the stimuli–response behavior. Accurate, selective, simple, and inexpensive detection method for sensing environmentally sensitive molecules is the primary requisite in the fast-growing technology world. The more complex nature of the environmentally polluting samples imposes a great challenge to the researchers to develop selective and accurate sensors. Gels are competent sensor materials owing to their macroscopic physical responses and their potential to act as optical and electrochemical sensors. The structure of these gels can be tuned to accomplish the detection of broad spectrum of pollutants. The selectivity in the detection of pollutants is enhanced by hybrid gels and suitably engineered gel nanocomposites. Gel-based materials exhibit improved analytical 238characteristics of sensors. Therefore, this chapter attempts to present an overview of the current state of research on supramolecular gel-based materials as sensors to sense environmentally sensitive molecules.