MXene-based biosensors for biomedical diagnostics: From molecular recognition to wearable systems

Two-dimensional transition metal carbides and nitrides (MXenes) have emerged as a versatile class of electroactive nanomaterials for next-generation biomedical diagnostics. Their metallic conductivity, tunable surface terminations (–O, –OH, –F), hydrophilicity, and compatibility with nanocomposite engineering enable efficient biomolecule immobilization and high-fidelity signal transduction across electrochemical, plasmonic, wearable, and implantable platforms. This review critically examines recent advances in MXene-enabled biosensors for oncology diagnostics, metabolic monitoring, neurotransmitter detection, and continuous physiological analysis. In cancer diagnostics, MXene-based immunosensors have achieved ultralow detection limits, including 0.0036 pg mL -1 for squamous cell carcinoma antigen and 1 nU mL -1 for CA15-3 and CA-19-9, while exosome detection has reached sensitivities of 19 particles μL -1 . In metabolic applications, MXene systems demonstrate nanomolar detection capability, rapid response times (as low as 2 s), and stable performance in whole blood and sweat matrices. Engineering strategies including noble metal hybridization, polymer stabilization, dendrimer functionalization, ratiometric sensing, and microfluidic integration are analyzed to elucidate structure–property–performance relationships. Wearable and implantable architectures further extend MXene functionality toward real-time health monitoring. Despite their promising analytical performance, important translational challenges remain, including oxidation susceptibility, biofouling, enzyme fragility, batch-to-batch reproducibility, large-scale manufacturing standardization, and limited long-term clinical validation. By integrating materials engineering with mechanistic insight, comparative analysis, and translational benchmarking, this review provides a strategic roadmap for advancing MXene biosensors from laboratory prototypes toward clinically viable and commercially translatable diagnostic technologies.