25 Aug Microfluidic detection of food allergens
Abstract
“The identification of accidental allergen contamination in processed foods is crucial for risk management strategies in the food processing industry to effectively prevent food allergy incidents. Here, we propose a newly designed passive stop valve with high pressure resistance performance termed an “air plug-in valve” to further improve microfluidic devices for the detection of target nucleic acids. By implementing the air plug-in valve as a permanent stop valve, a maximal allowable flow rate of 70 µL/min could be achieved for sequential liquid dispensing into an array of 10 microchambers, which is 14 times higher than that achieved with the previous valve arrangement using single-faced stop valves. Additionally, we demonstrate the simultaneous detection of multiple food allergens (wheat, buckwheat, and peanut) based on the colorimetric loop-mediated isothermal amplification assay using our diagnostic device with 10 microchambers compactly arranged in a 20-mm-diameter circle. After running the assays at 60 °C for 60 min, any combination of the three types of food allergens and tea plant, which were used as positive and negative control samples, respectively, yielded correct test results, without any cross-contamination among the microchambers. Thus, our diagnostic device will provide a rapid and easy sample-to-answer platform for ensuring food safety and security.”
“Schematic representation of the microfluidic diagnostic device allowing sequential liquid dispensing for multiplexed genetic allergen detection and fabricated using a combination of a soft lithography process and a wax reflow process. (a) A fabricated PDMS microfluidic device consisting of an array of five reaction microchambers (~ 3 µL each) was filled with green-colored water. (b) A piece of wax was placed on the top surface of each SU-8 chamber mold pattern. (c) Semi-ellipsoid-shaped wax molds formed with a uniform shape after heating at 135 °C for 3 min. (d) Scanning electron microscopy images of the PDMS microchamber. (e) 3D image and cross-sectional profiles of the PDMS microchamber.” Reproduced under Creative Commons Attribution 4.0 International License from Natsuhara, D., Misawa, S., Saito, R. et al. A microfluidic diagnostic device with air plug-in valves for the simultaneous genetic detection of various food allergens. Sci Rep 12, 12852 (2022).
Figures and the abstract are reproduced from Natsuhara, D., Misawa, S., Saito, R. et al. A microfluidic diagnostic device with air plug-in valves for the simultaneous genetic detection of various food allergens. Sci Rep 12, 12852 (2022). https://doi.org/10.1038/s41598-022-16945-2
Read the original article: A microfluidic diagnostic device with air plug-in valves for the simultaneous genetic detection of various food allergens