Figure 2.

Schematic representation of (a) multifunctional polyvinyl alcohol/MXene/polyaniline hydrogel. Reprinted with permission from RSC from ref. [68], (b) AuNPs@MoS₂-QDs composite with an agarose hydrogel-based stable visual platform in the presence of H₂O₂. The right diagram shows the UV–vis absorbance spectra of the hydrogel at various glucose levels (0, 2, 4, 5, 8, 10, 11, 12 mM) in serum. Reprinted with permission from Elsevier from ref. [69], (c) a flexible three-electrode system based on Ni-Co MOF-coated Au/PDMS hydrogel as a wearable electrochemical biosensor for glucose detection. Reprinted with permission from RSC from ref. [70], and (d) porous PVA/BTCA/β-CD/GOx/AuNPs composite integrated with PVA polymer nanofiber hydrogel synthesized by electrospinning method as a wearable glucose-responsive biosensor. Reprinted with permission from Nature from ref. [71].