Metric-driven biosensors for analyte detection

Protein-based biosensors are vital for environmental monitoring, diagnostics, and bioprocess control, yet many stall in the transition from laboratory to field because they fail to meet performance metrics. This review focuses on the adoption of a results-oriented, metric-driven framework focusing on (1) how molecular recognition couples to detectable output and (2) the engineering levers that tune the performance. Metrics such as the dynamic range, response speed, specificity, detectability, and biosensor stability are discussed. Biosensor implementation is treated as a design variable across whole-cell, cell-free, and immobilized formats. The review concludes with bottleneck-driven protein engineering strategies to meet these metrics and therefore facilitate broader applications across biological contexts.