DNA detection on ultrahigh-density optical fiber-based nanoarrays

Nanoarrays for DNA detection were fabricated on etched nanofiber bundles based on recently developed techniques for microscale arrays. Two different-sized nanoarrays were created: one with 700 nm feature sizes and a 1 μm center-to-center pitch (∼1 × 106 array elements/mm2) and one with 300 nm feature sizes and a 500 nm center-to-center pitch (4.6 × 106 array elements/mm2). A random, multiplexed array composed of oligonucleotide-functionalized nanospheres was constructed and used for parallel detection and analysis of fluorescently labeled DNA targets. We have used these arrays to detect a variety of target sequences including Bacillus thuringiensis kurstaki and vaccina virus sequences, two potential biowarfare agents, as well as interleukin-2 sequences, an immune system modulator that has been used for the diagnosis of HIV.