In this study, an
innovative gas sensing mechanism, self-responsive
sensing mechanism, has been detected in the supramolecular hydrogel-based
sensors. The self-responsive ability of as-fabricated hydrogel-based
sensors to the target gas (e.g., NO2, NH3, etc.)
is determined by three synergetic supramolecular interactions, namely,
hydrogen bonding, molecule crystallization, and electrostatic interactions
existing in hydroxyls, poly(vinyl alcohol) (PVA) crystallization,
and poly(ionic liquids) of the intrinsic hydrogel networks, respectively.
On account of unique synergetic supramolecular interactions, the sensors
not only exhibit a rapid, reversible, and reproducible response but
also show good tensile and compressive properties and excellent recovery
property. The results demonstrate the potential of the self-responsive
sensing mechanism as a pathway to realize a new generation of highly
responsive hydrogel-based gas sensors.