Multifunctional chitosan-based composite hydrogels engineered for sensing applications

• Published in: International journal of biological macromolecules 2024-10, Vol.278 (Pt 4), p.134956, Article 134956
• Main Authors: Ren, Jie, Wu, Zengyang, Wang, Bai, Zheng, Liuping, Han, Siyu, Hu, Jianshe
• Format: Article
• Language: English
• Subjects: Chitosan-based hydrogels; Conductive; Photothermal; Sensing
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.134956

Chitosan-based hydrogels, as natural high-molecular-weight flexible materials, are widely utilized due to their outstanding properties. In this research, we developed a one-pot method for synthesizing a novel PVA/CS@PPy-PDAx% conductive hydrogel and explored the internal bonding patterns through molecular dynamics simulations. By adding PPy-PDA nanoparticles into a hydrogel matrix, an interpenetrating conductive network established successfully. The uniform distribution of PPy-PDA nanoparticles endowed the hydrogel with good electrical conductivity (0.171 S/m), significantly enhanced mechanical properties, and strain sensing (S = 5.04), as well as near-infrared photothermal responsiveness (temperature increase of 41.9 °C within 30 s). Additionally, due to the hydrogel's significant photothermal conversion efficiency under near-infrared radiation, it exhibits rapid elimination of Escherichia coli with an antibacterial efficiency exceeding 90 %. The unique hydrogen-bonded crosslinked structure provides the hydrogel with excellent re-healing properties, allowing for restoration through a freeze-thaw process after damage. The conductivity remains nearly unchanged after re-healing, maintaining the material's integrity and functionality. The flexible sensor based on this hydrogel has a response time of 100 ms and can sensitively detect large-scale deformations (e.g., joint bending at various angles), different gravitational forces, and recognize human handwriting. These characteristics make this hydrogel a promising candidate for advancing intelligent wearable technologies and human-machine interaction systems. [Display omitted] •One-pot synthesis of chitosan-based hydrogel with PPy-PDA nanoparticles in PVA/CS matrix for advanced materials.•Uniform PPy-PDA nanoparticles in hydrogel enable good conductivity, enhanced mechanics, strain sensing, and NIR photothermal response.•Over 90% antibacterial efficiency against E. coli due to high photothermal conversion under 808 nm NIR radiation.•Unique hydrogen-bonded structure allows rehealing and restoration of integrity and function after damage, with stable conductivity.