%0 Journal Article
%A O’Sullivan, Shane
%A W. M. Arrigan, Damien
%D 2013
%T Impact of a Surfactant
on the Electroactivity of Proteins
at an Aqueous–Organogel Microinterface Array
%U https://acs.figshare.com/articles/journal_contribution/Impact_of_a_Surfactant_on_the_Electroactivity_of_Proteins_at_an_Aqueous_Organogel_Microinterface_Array/2446417
%R 10.1021/ac302222u.s001
%2 https://acs.figshare.com/ndownloader/files/4089085
%K 10 mM surfactant
%K Repetitive cyclic voltammetry
%K AOT
%K phase electrolyte salt
%K interface
%K protein desorption voltammetric peak
%K presence
%K cytochrome c
%X The impact of surfactant addition to the organic phase
on the electroactivity
of proteins at the aqueous–organogel interface was examined
by voltammetry. The presence of bis(2-ethylhexyl)sulfosuccinate (AOT)
in the organogel phase, as the sodium salt, caused marked changes
in the peak currents for myoglobin detection. The protein desorption
voltammetric peak exhibited a 6-fold increase in the current compared
to the corresponding experiment without surfactant. Interfacial coverage
showed a 17-fold increase in the adsorbed protein at the interface,
from 50 pmol cm–2, in the absence of surfactant,
to 850 pmol cm–2, in the presence of 10 mM surfactant.
Additionally, the presence of the surfactant resulted in a second
pair of adsorption/desorption peaks at lower potentials and in a change
in the capacitance of the system. The formation of surfactant–protein
and surfactant–protein–organic anion deposits is proposed
on the basis of these features, leading to increased voltammetric
signals for myoglobin, hemoglobin, and cytochrome c. The mechanism of protein–surfactant interaction was probed
by using the surfactant as the anion in the organic phase electrolyte
salt. Repetitive cyclic voltammetry of cytochrome c showed that in the presence of surfactant there was an enhancement
of the signal, caused by a buildup of the protein–surfactant–electrolyte
anion assembly at the interface. These findings provide the basis
for surfactant-modified interfaces to enhance the electroanalytical
performance for protein detection.
%I ACS Publications