Fabrication and optical characterization of imaging fiber-based nanoarrays

In this paper, we present a technique for fabricating arrays containing a density at least 90 times higher than previously published. Specifically, we discuss the fabrication of two imaging fiber-based nanoarrays, one with 700 nm features, another with 300 nm features. With arrays containing up to 4.5 × 106 array elements/mm2, these nanoarrays have an ultra-high packing density. A straightforward etching protocol is used to create nanowells into which beads can be deposited. These beads comprise the sensing elements of the nanoarray. Deposition of the nanobeads into the nanowells using two techniques is described. The surface characteristics of the etched arrays are examined with atomic force microscopy and scanning electron microscopy. Fluorescence microscopy was used to observe the arrays. The 300 nm array features and the 500 nm center-to-center distance approach the minimum feature sizes viewable using conventional light microscopy.