Microfluidic platform with hierarchical micro/nanostructures and SELEX nucleic acid aptamer coating for isolation of circulating tumor cells

Microfluidic platforms provide elegant schemes for isolation of rare cells from the blood. Hierarchical 3-dimensional architectures with silicon nanopillar forests draw advantage of unique surface interactions with target cells to aid capture and adhesion. Microchannels with numerically optimized designs of micro post arrays maximize contact frequency with the cells in flow. We describe a scheme to fabricate ordered nanopillar forests on the sidewalls of these micro posts and functionalize them with SELEX nucleic acid aptamers. Our microfluidic platform, designed for 90% contact probability, facilitates technologies for highly selective and specific capture of circulating tumor cells.