cell (potential scan rate = 500 mV/s). The encapsulating solution (1 mL of nanocapsule solution

or Tween-80 aqueous solution) is added to the cell, zero time is defined at the point addition is

complete, and the solution is stirred for 5 s with a magnetic stir bar. Further cyclic

voltammograms are then recorded versus time and the faradaic currents are determined for

uptake calculation. The faradaic current at t = 0 s was simply calculated by dividing the faradaic

current obtained in the initial cyclic voltammogram (before addition of the encapsulation

solution is done) by the dilution factor (6/5 for our experiments). Cyclic voltammograms were

not recorded simultaneously with stirring because otherwise the Randles-Sevcik equation used in

calculating the aqueous concentration of the probes during uptake would not be valid. The

experimental data and the error bars plotted correspond respectively to the average value and to

the standard deviation obtained from three different measurements.