Direct optical observation of DNA clogging motions near controlled dielectric breakdown silicon nitride nanopores

With the advantages of simple equipment and in-situ preparation of nanopores, the CBD method has been widely concerned by researchers. In this work, a fluorescence platform was set up to directly observe the lambda-DNA motions near the CBD prepared different kinds of SiNx nanopores. At first, for the one nanopore film, the lambda-DNA posttranslocation motion was observed. Then, for the multiple nanopores film, the current modulation phenomena of each nanopore after the DNA clogged the pores was observed. When the distance of asymmetric pores is less than the length of lambda-DNA, the larger nanopores are easy to be blocked preferentially by considering the tug-ofwar on lambda-DNA; when the asymmetric porous distance is larger than the DNA two polymer length, due to the forming a folded structure, the smaller nanopores are preferentially blocked. These results reveal that the clogging phenomena during the DNA translocation analysis for the nanopores are varied, and it should be considered for CBD-prepared nanopores.