**Background:** Food quality and safety are critical for protecting consumers from foodborne illnesses, which affect over 100 million people annually worldwide, including 32 million children under 5 years old. Traditional laboratory-scale analysis takes several days to complete, while methods such as PCR, ELISA, and accelerated plate culture tests have been proposed for faster detection. Lab-on-a-chip (LOC) devices and microfluidics offer miniaturized platforms that enable faster, easier, and point-of-interest analysis. This review aims to present an overview of recent advances in LOCs used for identifying the most prevalent foodborne and waterborne pathogens.
**Methods:** The review covers fabrication methods for both polymeric and paper-based microfluidic devices. Polymer-based methods include hot embossing (plate-to-plate and roll-to-roll), injection molding, casting/soft lithography (primarily using PDMS), micromachining (CNC and laser), 3D printing (FDM, SLA), optical lithography (SU-8), and plasma processing. Paper-based methods include wax printing, inkjet printing, optical lithography, screen printing, laser processing, plasma processing, and 3D printing/lamination. The review then surveys recent literature examples of LOC devices for detecting pathogenic bacteria in food and water samples, organized by pathogen type.
**Key Results:** For E. coli O157:H7 detection, a SERS-based microfluidic immunosensor detected 0.5 cfu/mL in romaine lettuce after 60 min enrichment, while a PCB-based RPA microfluidic device required only 0.6 W for DNA amplification. A MEMS biosensor achieved a LOD of 39 cfu/mL within 2 h, and a polycarbonate microchip using PCR detected 1.2 × 10⁻¹ cfu/mL from large-volume samples. For Salmonella, a MEMS biosensor with three microchannels achieved a LOD of 7 cfu/mL without pre-enrichment, while a PDMS-glass microchip using immuno-magnetic nanoparticles detected 58 cfu/mL in apple juice within 2 h. A paper-based device using Mie scattering detected a single Salmonella cell in 90 s. For Listeria monocytogenes, a duplex droplet PCR microchip detected 10 cfu/mL in drinking water within 2 h, and a self-priming compartmentalization microchip using LAMP detected 3.8 × 10² cfu/mL. For Staphylococcus aureus, a paper-based Y-shaped microchip with Au/Pt nanoclusters achieved a LOD of 80 cfu/mL within 5 min, and a PDMS immunosensor with nanoporous membrane detected 10² cfu/mL in 2 h. For Campylobacter, a polymer-based microfluidic device achieved 100% specificity in detecting multiple Campylobacter species and completed on-chip identification and AST in 24 h, with 91–100% concordance for antibiotic susceptibility testing. A dual-sample on-chip LAMP assay detected Campylobacter jejuni with a detection limit of 7.9 × 10⁻³ to 9.54 × 10⁻¹ pg of genomic DNA per reaction in 35 min.
**Clinical Implications:** LOC devices offer rapid, portable, and low-cost alternatives to traditional culture methods for foodborne pathogen detection, with many devices achieving detection limits comparable to or better than conventional methods. However, most devices have been evaluated under optimal laboratory conditions rather than real-world settings, and regulatory bodies such as the FDA have not yet approved their widespread use in quality control. The market for microfluidic chips is projected to reach $7.1 billion by 2025, driven by point-of-care testing demand and laboratory automation needs. Key challenges include the lack of mass production (keeping prices high), limited validation under sub-optimal conditions, and the need for further development to meet regulatory requirements for food microbiology.