Advances in Pathogen Detection by Nanosensors: Biorecognition Strategies, Signal Amplification, and Platform Engineering

The escalating global threat of infectious diseases, compounded by antimicrobial resistance (AMR), calls for improved diagnostic strategies. Conventional pathogen detection techniques─culture, enzyme-linked immunosorbent assay (ELISA), and microscopy─remain hindered by prolonged turnaround times, suboptimal sensitivity for low-abundance analytes, and operational intricacy. Nanosensor technologies have emerged as powerful enablers of rapid, ultrasensitive, and field-deployable diagnostics. This review delineates the convergence of three transformative domains: (1) advanced biorecognition strategies─including monoclonal antibodies, aptamers, bacteriophages, antimicrobial peptides, molecularly imprinted polymers, and lectins─that confer high-fidelity molecular selectivity within complex biological matrices; (2) multimodal signal amplification technologies, encompassing nanomaterial-enhanced mechanisms, enzymatic cascades, and isothermal nucleic acid amplification that drive detection down to the single-cell and femtomolar regimes; and (3) integrated platform engineering, uniting clustered regularly interspaced short palindromic repeats-Cas (CRISPR-Cas) systems, artificial intelligence (AI), and microfluidics to achieve multiplexed, real-time, point-of-care deployment. Advances are critically evaluated through standardized performance metrics─limit of detection, assay time, specificity, and operational simplicity─to reveal both synergistic opportunities and enduring translational bottlenecks. Collectively, these developments define a strategic framework for next-generation nanosensor diagnostics poised to revolutionize infectious disease surveillance and enable precision-guided therapeutic intervention.