In-Flow DNA Extraction Using on-Chip Microfluidic Amino-Coated Silicon Micropillar Array Filter

A silicon micropillar filter (μPF) chip was fabricated, glass-bonded, coated with 3-aminopropyltriethoxysilane (APTES) then tested for its ability to bind and release pre-purified DNA in continuous flow mode. APTES coated steps were used, which allowed direct detection of obtained DNA using UV Nano-Droplet. Both the capture efficiency and elution % were inversely proportional to flow rate, with such relation being more profound at higher DNA concentration. DNA elution recovery %, as high as 80%, was achieved under flow rate of 5 μl /min and an initial DNA loading of 250 ng. The capture capacity per surface area of the APTES-coated μPFis ~186 ng/cm2, which mounts to ~3.7 times the capacity of an identical uncoated filter. These results demonstrate the potential for integrating such amino-coated μPF in a lab-on-a-chip system for the extraction of nucleic acids directly from clinical samples in a continuous flow mode.