200 mm wafer-scale fabrication of polydimethylsiloxane fluidic devices for fluorescence imaging of single DNA molecules

We report fabrication of 200 mm silicon (Si)-wafer mold structure for polydimethylsiloxane (PDMS) microfluidic devices to demonstrate a real-time fluorescence imaging of single DNA molecules. Conventional photolithography with deep reactive ion etching process allows us to build a mesa-type Si mold with a nanoscallop sidewall geometry aiding PDMS residue-free process. By optimizing fluorescence microscopy with the fabricated PDMS chamber, we obtain a protocol to visualize the motions of single DNA molecules. This integrative PDMS-based single-molecule imaging system can, in principle, be used as a platform to study biochemical reactions occurring in proteins, nucleotides, and vesicles.