Integrated Micropillar Polydimethylsiloxane Accurate CRISPR Detection (IMPACT) System for Rapid Viral DNA Sensing

Kenneth N. Hass; Mengdi Bao; Qian He; Myeongkee Park; Peiwu Qin; Ke Du

The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.03.17.994137 doi: bioRxiv preprint those problems. In the future, on-chip treatment of blood infections can be achieved by immobilizing proper capture probes onto the IMPACT chip. 48, 49 Materials and Methods Device Fabrication: To create the IMPACT microfluidic chip, a mold was created using standard photolithography on a 100 mm silicon wafer. The silicon wafer was first dehydrated by baking it at 200°C for 20 min on a hot plate. After cooling to room temperature, SU-8 2075 (Microchem) was spun coat onto the silicon wafer with a thickness of 120 µm. The wafer was then left to sit for 10 min on a level surface to allow for reflow, and then soft baked on a hotplate at 65°C for 10 min, followed by 20 min at 95°C. After that, the wafer was exposed using a Karl Suss MA6 Mask Aligner for 15-20 s. It was then allowed to sit for 5 min, before receiving a post exposure bake at 80°C for 10 min. The sample was developed for ~10 min in SU-8 developer (MicroChem) and then sprayed down with IPA and dried. A final hard bake at 145°C was done on a hotplate for 5 min. After the hard bake, the wafer was silanized overnight using Silanization Solution I (~5% dimethyldichlorosilane in heptane) in a desiccator.