The electrophoretic deposition (EPD) of selfassembled
nanoparticles (NPs) on the surface of an electrode
is a new strategy for preparing sensor coating. By simply
changing the deposition conditions, the electrochemical
response for an analyte of deposited NPs-based coating can
be controlled. This advantage can decrease the difference
between different batches of sensor coating and ensure the
reproducibility of each sensor. This work investigated the
effects of deposition conditions (including deposition voltage,
pH value of suspension, and deposition time) on the structure
and the electrochemical response for L-tryptophan of sensor coating formed from Au-doped poly(sodium γ-glutamate) with
pendant dopamine units nanohybrids (Au/γ-PGA−DA NBs) via the EPD method. The structure and thickness of the deposited
sensor coating were measured by atomic force microscopy, which demonstrated that the structure and thickness of coating can
be affected by the deposition voltage, the pH value of the suspension, and the deposition time. The responsive current for Ltryptophan
of the deposited sensor coating were measured by differential pulse voltammetry, which showed that the responsive
current value was affected by the structure and thickness of the deposited coating. These arguments suggested that a rich designspace
for tuning the electrochemical response for analyte and a source of variability in the structure of sensor coating can be
provided by the deposition conditions. When Au/γ-PGA−DA NBs were deposited on the electrode surface and formed a
continuous coating with particle morphology and thinner thickness, the deposited sensor coating exhibited optimal
electrochemical response for L-tryptophan.


Rongli Zhang,Ye Zhu,Jing Huang,Sheng Xu,Jing Luo,and Xiaoya Liu.


ACS Appl.Mater.Interfaces