Carbon-dots tailored polyoxometalate-based conductive hydrogels for flexible sensing materials with both high...

Conductive hydrogels have emerged as promising materials for flexible wearable sensors, leveraging their intrinsic conductivity, mechanical flexibility, and biocompatibility. However, integrating high conductivity, strong toughness, and potent antibacterial activity into a single hydrogel material remains a formidable challenge. Addressing this, we fabricated a hydrogel (denoted PSPHC) via a facile one-pot synthesis, concurrently incorporating polyoxometalates (POMs, H₃PW₁₂O₄₀) and carbon dots (CDs), into a polyvinyl alcohol/sodium alginate (PVA/SA) semi-interpenetrating network. In the PSPHC hydrogel, POMs serve dual roles as exceptional conductive fillers and effective antibacterial agents, while CDs enhance mechanical toughness by promoting tighter cross-linking within the hydrogel network. Crucially, CDs also act as bridging units, reducing inter-POM distances and facilitating proton hopping to further boost conductivity. As a result, the PSPHC hydrogel exhibits outstanding mechanical property (tensile strain: 631 %, tensile strength: 1422.70 kPa, toughness: 3976.85 kJ m^-3), high proton conductivity (2.63 × 10^-1 S cm^-1 at 25 °C) and effective antibacterial capability. To our knowledge, this is the first study to jointly employ POMs and CDs in conductive hydrogel design, harnessing their synergistic effects for performance enhancement. Furthermore, the PSPHC hydrogel demonstrates excellent strain and temperature sensing capabilities, enabling real-time monitoring of human motion and physiological temperature changes. This work presents an innovative strategy for designing flexible sensing materials with integrated high conductivity, superior mechanical property and effective antimicrobial activity.