Recent applications and advancement of conductive hydrogels in biosensing, bioelectronics and bioengineering

Conductive hydrogels (CHs) are characterized by their distinctive three-dimensional (3D) network architecture enhanced by physically entangled or chemically cross-linked polymer chains. In recent years, these materials have garnered significant scientific interest owing to their unique combination of inherent electrical conductivity and remarkable capability to transduce external stimuli into measurable electronic signals. The immense potentials of those CHs in a number of applications catalyzed this review to summarize their specific properties and applications in biosensing, bioelectronics and bioengineering. Firstly, the preparation and unique properties of CHs were summarized, including mechanical properties, adhesion properties, self-healing capabilities, conductivity, biodegradability, and biocompatibility. We demonstrated tremendous potentials of CHs in the real world by showcasing their broad applications in biosensing (such as nerve sensing, strain sensing, glucose sensing, tumor sensing, temperature sensing, and environmental sensing), bioelectronics and bioengineering (such as treatment of cardiac and wound healing). Finally, by presenting current challenges and issues of CHs, future potential research directions were outlined for their applications in the study of biosensing, bioelectronics and bioengineering.