Biosensors & Bioelectronics

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

Abstract

Hanaa M Hegab, Soliman M, Ebrahim S and Op de Beeck M

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 μPF was tested over different DNA initial loading amounts and flow rates. Simple and effective washing and eluting 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.