Palladium-bridged polymers as CO-biosignal-responsive self-healing hydrogels†
Constructing gas-sensitive hydrogels is a new direction of soft matter. Carbon monoxide (CO) is one of the most vital gas molecules in living organisms, whose dysfunction is related to serious human diseases. Here, we report a CO-responsive self-healing hydrogel system that is formed by a palladium (Pd)-cross-linked polymer network. The introduction of dynamic Pd-bridged metal-coordination units into the macromolecular chains can endow the network with CO-triggered gel-to-sol transition behavior and fast recoverable capacity to mechanical damage. We envisage that this polymer hydrogel would expand the repertoire of metal hydrogels and provide a new platform for gas-stimulated smart soft materials.