Fabrication of DNA extraction device with tethered poly(N-isopropylacrylamide) brushes on silicon surface for a specific DNA detection

In this work, tethered poly(N-isopropylacrylamide) (PNIPAAm) with thermo responsive property brushes were grafted on a fluidic device by atom transfer radical polymerization (ATRP) as a extractor of DNA molecules from a specimen of human blood through temperature tuning. The thermo responsive property of temperature switching for tethered PNIPAAm was introduced to absorb DNA molecules at T = 25 °C and release them at T = 60 °C. The specimen included a human genomic DNA (hgDNA584), a designed target DNA molecule with 2, 10, and 50 ng/μl concentrations, and biomarcomolecules from lysing human blood. A set of specific primers of polymerase chain reaction (PCR) process were designed to control the selectivity of specific DNA detection. We analyzed the specimen after amplification by agarose gel electrophoresis to recognize the existence of the hgDNA584. The results suggest that 2 ng/μl of hgDNA584 the fluid device could be extracted by tethered PNIPAAm brushes to be detected after PCR process, which could miniaturize cartridges of sample preparation for rapid disease diagnosis through fluid device to approach the lab-on-a-chip (LOC).