As the food industry expands and the number of consumers increases, food safety is becoming more important worldwide. However, the outbreak of food poisoning caused by foodborne pathogenic bacteria is a great threat to food safety. Salmonella is one of the major causes of foodborne illness. However, conventional methods such as the selective culture method, polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA) for detecting foodborne pathogenic bacteria are time-consuming, labor-intensive, and require complicated equipment to measure. Thus, we developed a microfluidic chip for detecting pathogens rapidly, accurately, and sensitively. The form of the chip was created based on the lateral flow immunoassay (LFIA) commonly used for rapid diagnosis. The sensing surface is composed of two capture areas, a test area that captures immune complex of pathogens and particles and a control area that captures the residual particles not reacted with target pathogens. By applying the form of LFIA to a microfluidic chip and using retro-reflective particles as a signal probe, it was possible to simultaneously perform a high-sensitivity quantitative analysis of foodborne pathogens and judge the effectiveness of the chip. Furthermore, by using the characteristics of retro-reflective particles even in non-spectral light, it was possible to detect bacteria with simple optical equipment. In this study, the concentration of Salmonella Typhimurium was measured ranging from 0 to 103 CFU/mL. As a result, we could rapidly detect Salmonella Typhimurium up to the limit of detection to 10 CFU/mL.
