Figure 4.

Cellular labeling and imaging using AuNCs. A) HeLa cells were treated with (a, b) Au-MUDA NCs and (e, f) Au-MUDA-NLS NCs for 1.5 h. The left panel shows the one-color image. The right panel shows the two-color colocalization image of HeLa cells incubated with Au-MUDA-NLS NCs and counterstained with membrane dye WGA–Alexa 594 and nuclear dye SYTO 59; scale bar: 25 μm. B) Schematics showing the etching method to prepare luminescent AuNCs and their conjugation with streptavidin. C) (a) Fluorescence, (b) bright-field, (c) and overlay of fluorescent and bright-field images of human hepatoma (HepG2) cells stained with streptavidin-conjugated Au₂₃ NCs. Figure panel 4A is adapted with permission from [86], copyright 2008 The Royal Society of Chemistry. Figure panel 4B is reused and panel 4C is adapted with permission [87], copyright 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim.