Robust Wearable Sensors Based on Silk Fibroin Hydrogels Enforced by Spherical Polyelectrolyte Brushes with Metal...

Flexible sensors are crucial for the continuous monitoring of personal health conditions, enabling personalized health management, but the integration of desirable mechanical strength, electrical conductivity, sensitivity, and biocompatibility within a single hydrogel sensor continues to pose a substantial challenge. In this study, spherical poly(acrylic acid) brushes (SPBs) on a polystyrene core were employed as nanoreactors for the in situ preparation and immobilization of conductive metal nanoparticles. The nanofillers were dispersed into the aqueous solution of glycidyl methacrylate-modified silk fibroin (SF-GMA), followed by photoinitiated polymerization to form the hydrogel. The introduction of SPB served as effective nanofillers, and the in situ synthesis strategy enabled precise control over the size and dispersion of conductive metal nanoparticles, thereby improving the electrical conductivity of the composite hydrogel. The performance of the hydrogel was significantly enhanced by incorporating only a small number of functional nanofillers. The resulting hydrogels exhibited a high elongation at break (260%), good adhesive strength (35.4 kPa), excellent conductivity (63.1 mS/m), and response time (0.23 s). This work presents a promising strategy for the design of multifunctional flexible electronic materials and offers considerable potential for future biomedical applications.