Fabrication of gold nanodot arrays on a transparent substrate as a nanobioplatform forlabel-free visualization of living cells

Abstract

Two-dimensional gold (Au) nanodot arrays on a transparent substrate were fabricated forimaging of living cells. A nanoporous alumina mask with large-area coverage capability wasprepared by a two-step chemical wet etching process after a second anodization. Highlyordered Au nanodot arrays were formed on indium–tin-oxide (ITO) glass using very thinnanoporous alumina of approximately 200 nm thickness as an evaporation mask. Thelarge-area Au nanodot arrays on ITO glass were modified with RGD peptide(arginine; glycine; aspartic acid) containing a cysteine (Cys) residue and then used toimmobilize human cancer HeLa cells, the morphology of which was observed byconfocal microscopy. The confocal micrographs of living HeLa cells on Au nanodotarrays revealed enhanced contrast and resolution, which enabled discernment ofcytoplasmic organelles more clearly. These results suggest that two-dimensional Aunanodot arrays modified with RGD peptide on ITO glass have potential as abiocompatible nanobioplatform for the label-free visualization and adhesion of livingcells.