Preparation Of The Low Cost, Fast Paper-Based Microfluidic Device And Its Application In Food Safety

Food is important to everyone as it is necessary for human survival and its safety is related to each person’s health. Currently people have paid more and more attention to food safety, which is closely linked to everyone’s health. Food safety is not only a way that people gain energy, but also a feasible way of human disease prevention in the future. Researchers in the world try to broaden the scope of the detection and modern advanced analysis techniques to solve this problem.Chemicals of different categories are need to be detected when food as the analysis samples. It is difficult to carry out multiple detection of different type of chemicals because of the different chemical microenvironment requirements. Herein, a low-cost and simple paper-based micro fluidic device integrated with fluorescence labeled single-stranded DNA (ssDNA) functionalized graphene oxide sensor was developed for the multiplex determination of different types of chemical contaminants in food. The chemical compatibility was enlarged, which made it possible to simultaneously detect multiple chemicals under the same chemical microenvironment. In addition, the device could be easily fabricated through wax printing. The wax provided the hydrophobic barrier to form hydrophilic areas for detection. Therefore it was also low-cost and portable. The sample could be introduced easily by capillary action through the hydrophobic channel without any additional liquid driving device. This device had been successfully applied into multiplex detection of heavy metal Mercury (II) ion (Hg2+), Silver (I) ion (Ag+) and aminoglycoside antibiotics residues in food.Besides of these harmful chemicals in the food, food borne pathogens as a kind of biological substances also cause damage to the safety of the food. In this study, we made 3D paper-based micro-culture device with the usage of the metal mould. The traditional colorimetric assay and colony counting method have been applied to the detection of food borne pathogens based on this detection device. With this 3D paper-based micro-culture device, the experimental operation was simplified, Less manpower, material resources and time were required and the cost was reduced when food-borne pathogens was detected. In this study, Salmonella and Staphylococcus aureus were detected by this method successfully. It provides enormous potential for applications in food safety, environmental monitoring and clinical diagnosis.