MXene‐Based Electrochemical Sensors: Design Strategies and Application Advances for the Detection of Biological Small Molecules

Precise detection of biomolecules is crucial for disease diagnosis. Traditional detection methods suffer from limitations such as slow results and high costs, restricting their practical application. While electrochemical sensors offer advantages such as rapid detection, ease of operation, and low cost, they are fundamentally constrained by electrode materials. Among numerous candidates, MXene stands out due to its unique 2D structure, enormous specific surface area, excellent conductivity, and abundant surface functional groups (e.g., the electron transfer rate constant of Ti 3 C 2 Tx exceeds that of conventional materials by 2–3 orders of magnitude), making it one of the ideal materials for electrochemical sensor fabrication. This article comprehensively reviews the latest advances in MXene‐based electrochemical sensors for biomolecular detection. It systematically elucidates sensing principles, performance metrics, and material design strategies and for the first time distils a “design grammar” for MXene‐based sensors. This establishes universal design principles linking material characteristics (e.g., terminal functional groups and heterostructures) to detection performance (e.g., achieving a glucose detection limit at the aM level). Analysis indicates these rules can guide the construction of sensing interfaces that simultaneously achieve ultrahigh sensitivity, selectivity, and stability. This design framework not only points the way for developing high‐performance MXene sensors but also provides a critical theoretical framework and practical guide for rational optimization and novel sensing interface design in electroanalytical chemistry, advancing its practical applications in clinical diagnostics and personalized medicine.