Phage-based biosensors for pathogen detection

Pathogenic bacteria continue to pose a severe and persistent threat to global public health, necessitating the development of rapid, sensitive, and reliable detection systems. Bacteriophages (phages), owing to their exquisite host specificity and biological robustness, have emerged as powerful biorecognition elements in biosensor development. This review provides a systematic analysis of recent advances in phage-based biosensing, with a particular emphasis on their modular design. We first discuss three fundamental phage-based recognition strategies for sensor construction: immobilization-based capture, phage amplification, and reporter phage systems. The application of synthetic biology tools, such as CRISPR genome editing and directed evolution, alongside interface engineering strategies, such as site-specific immobilization is discussed to precisely regulate the phage-sensor interface and enhance biosensor performance. Various signal transduction platforms, ranging from label-free techniques to reporter-based amplification are summarized, and their roles in translating biological recognition into quantifiable outputs are described. The convergence of phage engineering and computational tools for next-generation biosensor design is highlighted, particularly within a design-build-test-learn framework. Finally, we explore future directions, including AI-assisted phage design, theranostic applications, and the transition toward programmable, adaptive biosensing systems, aiming to establish intelligent platforms for precise clinical diagnosis and on-site environmental monitoring.