Jegan Rajendran, Gymama Slaughter
MXenes, a rapidly expanding family of two‐dimensional transition metal carbides and nitrides, have emerged as leading materials for wearable bioelectronics due to their metallic conductivity, termination‐rich surfaces, mechanical compliance, and tunable interlayer structures. However, wearable biosensor performance does not arise from conductivity alone, but from coupled interactions among surface termination chemistry, heterointerface engineering, hierarchical architecture, and device integration under dynamic physiological conditions. This review establishes a predictive structure‐interface‐device framework linking MXene chemistry to system‐level performance across electrochemical, mechanical, gas, optical, and energy‐storage modalities. We analyze how termination‐controlled adsorption governs charge transfer and selectivity, how heterojunction formation modulates carrier density and signal amplification, and how interlayer engineering and restacking suppression regulate ion transport, durability, and stability. Beyond materials design, we evaluate system‐level constraints including impedance stability, wireless communication, AI‐enabled analytics, and self‐powered operation. Key translational challenges, such as oxidation resistance, biocompatibility, scalable manufacturing, and reliable performance in complex biofluids, are assessed using quantitative benchmarks relevant to real‐world wearable deployment. By integrating nanoscale interfacial physics with device and systems engineering, this review defines generalizable design principles for durable, selective, and energy‐autonomous MXene‐enabled biosensors for intelligent, connected, and clinically translatable wearable platforms.