Ag-Anchored Ti3C2Tx-Polyacrylamide Hydrogels with Interlayer Electron Bridges for Stretchable Bioelectronics and Photothermal-Assisted Therapy.

Stretchable bioelectronic hydrogels must reconcile extreme mechanical compliance with stable, high-fidelity charge transport and therapeutic functionality. We introduce a Ag-anchored Ti3C2Tx-polyacrylamide (PAM) hydrogel, in which silver nanoparticles bridge adjacent MXene layers, thereby lowering interlayer resistance and forming a continuous, strain-adaptive conductive network. Concurrent metal-polymer co-ordination with 2D MXene reinforcement yields a hierarchical dissipation architecture featuring ultra-stretchability (∼2036%), high toughness (∼2350 kJ m-3), and rapid self-recovery under cyclic loading. Electron-bridge-enabled transport results in stable electro-mechanical sensing (linear ΔR/Ro up to 500% strain; R2 ≈ 0.98) and minimized skin-electrode impedance at 1.5 mm thickness across 1 Hz-10 kHz, outperforming commercial Ag/AgCl electrodes. In human tests, the hydrogel electrodes capture high-fidelity sEMG (SNR ≈ 30 dB) and ECG (SNR ≈ 26.157 dB) with 5-day stability. At the same time, photothermal actuation at 808 nm and 1 W cm-2 rapidly reaches ∼74 °C and cycles reproducibly, enabling dose-tunable therapeutic heating. The platform also demonstrates >90% fibroblast viability and significant suppression of S. aureus growth. By coupling interlayer electron bridges with dynamic bonding, this work establishes a unified design principle for multifunctional, clinically oriented soft hydrogels that span wearable physiological monitoring and NIR-assisted therapy.