MXene quantum dot–integrated wearable and implantable biointerfaces for continuous physiological and clinical health monitoring

MXene quantum dots (MQDs) are an emerging class of quantum-confined nanomaterials with potential for integration into wearable and implantable platforms for physiological and clinical monitoring. Their combination of high electrical conductivity, tunable optical behavior, and modifiable surface chemistry supports multiple signal-transduction pathways in complex biological environments. This review examines the physicochemical determinants governing MQD performance, including quantum confinement, surface terminations, charge-transport characteristics, and structural stability, and discusses how these properties influence device-level sensing behavior. Recent progress in incorporating MQDs into flexible, skin-conformal, portable, and potentially implantable architectures is evaluated with particular attention to biointerface design, mechanical compliance, analyte accessibility, and low-power transduction. MQD-based sensing approaches involving electrochemical, fluorescent, electrochemiluminescent, photothermal, and related modalities are reviewed for applications including serum biomarker analysis, nucleic-acid detection, intracellular redox assessment, neurotransmitter sensing, and metal-ion monitoring. Importantly, the distinction between laboratory proof-of-concept sensors and systems that have undergone genuine wearable, implantable, or long-term physiological validation is emphasized. Remaining challenges include batch-to-batch variability, oxidation-induced signal drift, biofouling, chronic biocompatibility, scalable manufacturing, and regulatory validation. Overall, current evidence indicates that MQDs provide a versatile materials platform for future biointegrated monitoring technologies, although further device-level, in vivo , and long-term validation is required before routine clinical deployment.