Size-controllable quartz nanostructure for signal enhancement of DNA chip.

A mask-free, cost-effective dry-etching method for the fabrication of height- and spacing-controlled, pillar-like nanostructures was established in order to detect DNA molecules. The height and spacing of the quartz nanostructure were regulated by successive O(2) and CF(4) reactive ion etching times. The height and spacing of the nanostructures were tuned between 118 and 269 nm and between 107 and 161 nm, respectively. Probe DNA was immobilized on the structure and hybridized with fluorescently-labeled target DNA. Increases in the height and spacing of the nanopillar structure positively correlated with the fluorescence intensity of bound DNA. Usage of the nanostructure increased the DNA detection limit by up to 100-fold.