Stimuli-responsive hydrogels based on protein/peptide and their sensing applications

Stimuli-responsive hydrogels are smart three-dimensional materials containing a huge amount of water, which can respond to different stimuli. Typical polymeric hydrogels can be designed for a range of stimuli at low cost. However, polymeric hydrogels are less capable of sensing specific biological stimuli or biomolecules owing to the lack of specificity, which led to emerging hydrogels using proteins, peptides, aptamers and so on. In this paper, we outline the recent progress made in the fast-growing field of protein/peptide-based stimuli-responsive hydrogels. Specially, an emphasis is given to the protein/peptide-based hydrogels fabricated by different building blocks, namely, helix self-assemblies, β-sheet and β-hairpin self-assemblies, protein/peptide incorporating active domains, protein/peptide monomers, and their unique structures and properties. The latest development of stimuli-responsive protein/peptide-based hydrogels in physical, chemical and biological sensor applications are then reviewed. Finally, we discuss the challenges and envision future development of biomacromolecular hydrogels and their potential applications.