Figure 5.

Dodecanethiol adsorption to a single Au nanoantenna in a single nanochannel. (a–c) Schematic depictions of the different phases of the experiment, which was comprised of initial flushing of the nanochannel with ethanol (a), followed by flushing with dodecanethiol solution (b) and rinsing in pure ethanol (c). The arrows indicate the direction of the applied flows from the two connected microchannels acting as reservoirs for pure ethanol and dodecanethiol solution, respectively. (d) The time-dependent LSPR shift, Δλ of an individual gold nanosensor in a nanochannel initially filled with ethanol upon exposure to (50 mM) ethanol-based dodecanethiol solution, followed by a rinsing step in pure ethanol. The observed kinetics and the magnitude of the final Δλ-value compare well with reported LSPR shifts caused by thiol molecules binding to gold or silver nanoantennas of similar dimensions, and the finite Δλ-value upon rinsing shows the irreversible character of the binding process, as expected for a thiol.