Nanomaterial-enabled bioanalytical sensing for doping detection: a critical review of signal transduction, matrix effects, and translation barriers.

Doping control requires rapid, field-deployable screening tools to complement laboratory-based confirmatory methods. Nanomaterial-enabled sensors offer portable and easy-to-use platforms by integrating signal amplification, molecular recognition, and small-volume sample analysis. However, despite increasing demonstrations in biological samples, many reported sensors still lack the comprehensive validation required for routine anti-doping practice, including standardized evaluation in diverse authentic samples, matrix-matched calibration, reproducibility assessment, and comparison with established analytical workflows. Therefore, this review evaluates nanomaterial-enabled doping sensors from a matrix-oriented and application-driven perspective. Noble-metal, fluorescent, carbon-based, magnetic, MOF-based, and nanozyme platforms are discussed together with integrated strip-based and wearable formats, covering plasmonic, fluorescence, electrochemical, magnetic, catalytic, SERS, LFIA, and flexible sensing strategies. Particular emphasis is placed on how biological matrices affect target capture, signal generation, quantitative reliability, and field applicability. Key translation barriers are identified, including matrix tolerance, batch-to-batch variability, insufficient standardization, limited authentic-sample validation, and weak integration with anti-doping workflows. By linking material design, sensing format, matrix-specific validation, and practical deployment requirements, this review defines a matrix-oriented framework for assessing the translational potential of nanomaterial-enabled anti-doping sensors.