Improving the Skin-Conformability of Wearable Continuous Glucose Monitors With Synthetic Hydrogel Electrodes.

Synthetic bioelectronics is rapidly advancing, propelled by breakthroughs in synthetic biology and bioelectronics. This convergence is key to next-generation wearable and implantable devices, enabling seamless integration with living systems. Here, we introduce an enzymatic hydrogel electrode (GelZymes) developed via a synthetic bioelectronic strategy to overcome the mechanical and interfacial limitations of conventional enzyme electrodes. GelZymes deliver two core advances: i) a monolithic and scalable 3D architecture that unifies the enzyme membrane and electrode, simplifying fabrication and eliminating interfacial instability; and ii) tissue-like viscoelasticity-combining stretchability and adhesiveness-rarely achievable with rigid enzyme membranes. GelZymes are synthesized through three steps: engineering a stretchable, mixed-conducting 3D hydrogel; implementing an enzyme-compatible, cascading crosslinking scheme to immobilize enzymes within the network; and balancing the trade-off between electronic/ionic conductivity and the density of redox-active enzyme sites to maximize bio-electrochemical performance. We further show that GelZymes enable a shift from invasive, tissue-interfaced biosensing to noninvasive, tissue-integrated biosensing, offering a practical pathway to bridge current biosensor technologies with living systems.