Abstract:
The gold electrodes modified with organic compounds (frequently organic thiols and their derivates), represent
a new category of devices which are widely used in molecular recognition, in special in case of biomolecules analysis.
Alkanethiols are spontaneously adsorbed on the gold surface and form a monomolecular film, with a highly ordered
structure, called a self-assembled monolayer (SAM). This represents a promising approach which offers the possibility of
design and assembling desired structures at molecular level. One of the main disadvantages in the utilization of these kinds
of electrodes at large scale is the relative high cost of gold electrodes manufactured on specialized companies. Starting
from these, we try to obtain the gold electrodes by electro-chemical deposition of gold, on platinum wire. These electrodes
can be easily obtained in laboratory, with common laboratory equipments and are not so expensive. The obtained
electrodes have been characterized with cyclic voltammetry and electrochemical impedance spectroscopy (EIM). The
experimental results have show that the analytical performances of these electrodes (quantity of thiol retained on surface,
permeability degree, stability in time of obtained monolayer, etc.) are comparable with those obtained in case of
manufactured gold electrodes. The elctrodes have show higher reproducibility in their electrochemical behaviour as well as
in their modification, and was prepared to be utilized in the detection of humic acid molecules from environmental
samples.
Keywords:
gold electrodes, electro-deposition, self-assembled monolayer, thiol, cyclic voltammetry, electrochemical impedance spectroscopy
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