Isothermal nucleic acid amplification based microfluidic “lab-on-a-chip” for the detection of pathogenic bacteria and viruses in agri-foods

Food safety is a global health issue. The major causes of foodborne diseases, including bacteria, viruses, parasites, prions, and chemicals in unsafe food, lead to severe outbreaks worldwide annually. Traditional detection technologies such as polymerase chain reaction (PCR) rely on complex thermal apparatus, hindering their applications in novel integrated devices and high-throughput analysis for point-of-care tests for foodborne pathogenic bacteria and viruses. Isothermal nucleic acid amplification-based lab-on-chip (LOC) technology represents an alternative approach to on-site detection, as it does not require programmed temperature control. In addition, miniaturized microfluidic LOC can reduce the use of reagents and the need of other expensive equipment. We summarized the recent progress in the application of isothermal nucleic acid amplification-based microfluidic LOC devices used in agri-foods for the detection of pathogenic bacteria and viruses. The potential and limitations of these methods were also analyzed. Nucleic acid sequence-based amplification (NASBA), hybridization chain reaction (HCR), rolling circle amplification (RCA), recombinase polymerase amplification (RPA), and loop-mediated isothermal amplification (LAMP)-based LOC devices have been successfully developed and applied for the detection of pathogenic bacteria and viruses in agri-foods due to their high sensitivity, specificity, and rapid response. By integrating sample pre-processing and extraction either before or on a single chip, it becomes possible to minimize interference signals from food sample matrix before the nucleic acid amplification step. Further optimization and development hold the potential to improve the performance of these devices, expanding their uses in the surveillance and control of foodborne or food-related diseases.