Development Of The Animal Derived DNA Concentration Detector Based On Paper-based Microfluidics

Animal derived food is made from the meat, skin and bone of animal, which is rich in animal protein and DNA. With the development of Chinese economy and the growth of material needs, the consumption of animal derived food increases rapidly. Driven by the interests, the problem of animal derived food adulteration becomes more serious, and the society is crying for a simple, rapid and accurate method for the detection of animal derived food. But at present, the d etection of animal derived ingredients is lack of rapidity, accuracy and commercialization. Therefore, in this paper, we combine the flexibility, affordability and rapidity of paper-based microfluidics with the accuracy of DNA detection, and propose a animal derived DNA concentration detection method based on paper-based microfluidics.Firstly, this paper studies in the theory of Electrochemical DNA detection based on paper-based microfluidics. Step one, according to the difference of mt COI gene in different species, we design the DNA Front Probe with mercapto group and the DNA Back Probe with amino, and the two kinds of probe can bind the ends of Target DNA specifically. Step two, according to the interaction between Au NPs and mercapto group, and the interaction between Au NPs and amino, it is available for the self-assembly of the DNA Back Probe on the surface of Au NPs and the DNA Front Probe on the surface of electrodes. Step three, after adding the Target DNA to the paper-based microfluidics, Target DNA can bind the DNA Front Probe and the DNA Back Probe respectively, and then connect Au NPs to the electrodes, which can reduce the resistance and increase the current of paper-based microfluidics, and there is a linear relationship between the logarithm of the DNA concentration and the current of paper-based microfluidics.Under the guidance of Electrochemical DNA detection theory, the manufacture of paper-based microfluidics and the development of the DNA concentration detector are detailed researched in this paper. By handwork, we design and manufacture 2D and 3D paper-based microfluidics with four channels, and by using the mixture of the conductive carbon paste and the reduced graphene oxide with Au NPs to manufacture the electrodes of paper-based microfluidics, we can decorate the electrodes with Au NPs and prepare for the self-assembly of the DNA Front Probe on the surface of electrodes. And then based on the C8051F340 singlechip and the independence between the parallel circuit branches, we develop an animal derived DNA concentration detector with four channels which can measure the current of four channels respectively, and use Keil for singlechip programming.Lastly, according to the experiments of animal derived DNA detection, the linear relationship between the logarithm of the DNA concentration and the current of paper-based microfluidics is verified in this paper. And by data analysis and calculations, we get the linear parameters of this relationship. By updating the linear parameters to singlechip program, we can detect animal derived DNA concentration.In conclusion, in this paper we combine paper-based microfluidics with Electrochemical DNA detection, and develop a animal derived DNA concentration detector based on paper-based microfluidics, which opens up a new path for the detection of animal derived ingredients.