An integrated microfluidic platform for on-site qPCR analysis: food allergen detection from sample to result

Improving food safety is crucial in the context of a "One Health" approach. To guarantee product quality and safety, the food industry, which has a very high turnover rate, needs short time-to-result analyses. Therefore, user-friendly systems at the point-of-need are necessary, presenting relevant analytical information and fulfilling the current regulations. To answer these challenges, a microfluidic platform integrating sample preparation and subsequent multiplex qPCR detection has been developed for on-site testing. The system consists of a fully automated instrument driving a microfluidic cartridge dedicated to the detection of multiple allergens in complex food matrices. The first part of the microfluidic cartridge contains pumps, reservoirs, valves and a filter to achieve DNA extraction, concentration and purification. Multiplex qPCR detection is carried out in the second part of the cartridge including a negative control chamber and five chambers for target analyte detection. The in-house developed instrument contains all functions to autonomously drive the microfluidic cartridge: pneumatic control for fluid actuation, thermal control for qPCR amplification and an optical system using three fluorescent wavelengths for multiplex detection of the target analytes and controls. We demonstrate the simultaneous detection of four different allergens - gluten, sesame, soy and hazelnut - from various complex food matrices. The turn-around-time from sample to result is close to two hours and controls in place validate the obtained results. For gluten, a direct comparison with ELISA shows that the regulatory threshold of 20 ppm is comfortably fulfilled. Moreover, all results are in agreement with external laboratory analyses performed in parallel on the same samples. Our findings confirm that the system can be used safely on-site without the risk of cross contamination between the various samples being analysed. In conclusion, our microfluidic platform offers a robust method for on-site allergen management.