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 80


 O 0 50 1000 150 2000
 r ~ ~~Tm in seconds1_- II
 Fiur -1. pak o erocn dmehno vrustiein0.7wt% M S ancpsl
 souio btta ocetato: w ) i .2 t MO aocpul olto




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 Asstated earie, toall cnethein t%, n02 tTO nanocapsule sapewrextnilydlzdinordertio




eliminate, as much as possible, potential contaminants besides the nanocapsules, and especially

residual Tween-80 micelles. Uptake measurements were also carried out on Tween-80 aqueous

solutions to check if Tween-80 micelles could influence the uptake. Micellar envelopes have

been shown not to influence the electron transfer between the encapsulated species and the

working electrodes, and therefore only the decrease in the diffusion coefficient of the

encapsulated species influences the electrochemical signal.247-250 As determined by DLS, the

radius of Tween-80 micelles is approximately 4 nm, which leads from the Stokes-Einstein

equation to a diffusion coefficient around 6x10-7 cm2/S. It is a factor 10-102 times smaller than

the diffusion coefficient of single molecules like ferrocene methanol and ferrocene dimethanol;

therefore, encapsulation by Tween-80 micelles can easily be seen with cyclic voltammetry as