Abstract
Stimuli-responsive gels that exhibit a volume change in response to an environmental change have attracted much attention as smart soft materials for sensors, actuators, drug delivery systems and other applications. We proposed a novel strategy for designing molecularly stimuli-responsive gels, “molecule-responsive gels”, which undergo changes in the volume in response to a target molecule. The strategy utilizes molecular complexes as dynamic crosslinks that reversibly associate and dissociate in response to a target molecule. Two types of molecule-responsive gels have been developed using various molecular complexes as dynamic crosslinks: “biomolecule-crosslinked gel” and “molecule-imprinted gel.” The biomolecule-crosslinked gels swell and molecule-imprinted gels shrink in the presence of a target molecule because their crosslinking densities change by dissociation and association of molecular complexes as dynamic crosslinks. This review focuses on molecule-responsive gels that show swelling/shrinking changes in response to a target molecule such as glucose, antigen, tumor marker and endcrine disrupting chemicals. Furthermore, molecule-responsive gel nanoparticles, thin layers, micro-valves for various applications such as DDS, sensor and microfluidics are described in the review.
