MXene-based biosensors for pathogen detection: materials synthesis, sensing mechanisms, and analytical applications

Rapid and accurate pathogen detection is essential for disease diagnosis, food safety, environmental monitoring, and public health surveillance. Conventional detection techniques, including culture-based assays, polymerase chain reaction (PCR), high-performance liquid chromatography (HPLC), and immunoassays, require lengthy analysis time, complex sample preparation, high costs, and sophisticated instrumentation. These challenges have accelerated the development of MXene-based biosensors as promising alternatives for rapid and sensitive pathogen detection. Owing to their exceptional electrical conductivity, large specific surface area, tunable surface chemistry, and excellent biocompatibility, MXenes have emerged as attractive two-dimensional nanomaterials for biosensing applications. This review summarizes recent advances in MXene-based biosensors for pathogen detection, covering synthesis strategies, physicochemical properties, recognition elements, signal transduction mechanisms, and practical applications. Both top-down and bottom-up synthesis approaches are discussed to highlight their influence on MXene properties. The roles of antibodies, aptamers, nucleic acids, peptides, and molecularly imprinted polymers are critically examined, together with electrochemical, optical, fluorescence, and electrochemiluminescence sensing strategies. Furthermore, applications in food safety, environmental monitoring, clinical diagnostics, and wearable sensing devices are reviewed. Despite remarkable progress, challenges related to oxidation stability, restacking, poor long-term storage, batch-to-batch reproducibility, and scalable synthesis remain. These represent significant disadvantages of MXenes compared with conventional nanomaterials. Finally, future perspectives focus on green synthesis, multifunctional nanocomposites, wearable biosensors, and artificial intelligence-assisted data analysis. This review provides a comprehensive perspective on MXene-based biosensors and their potential for next-generation pathogen detection technologies.