ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 4, pp. 699−705. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © A.S. Kosykh, N.A. Malakhova, S.Yu. Saraeva, L.I. Kolyadina, A.S. Vokhmintsev, A.V. Ishchenko, I.A. Weinstein, 2015, published in Zhurnal
Prikladnoi Khimii, 2015, Vol. 88, No. 4, pp. 652−658.
Owing to large speciﬁ c surface area, good conductivity,
and high adsorption power , carbon nanotubes (CNT)
are widely used today as modiﬁ ers of the surface of
indicator electrodes for voltammetry. The simplicity
of voltammetric measurements, low detection limits of
elements being determined, short analysis time, reliability,
and small size and low cost of the equipment allow
stripping voltammetry (SV) to compete with other high-
sensitivity methods (e.g., atomic absorption spectroscopy,
mass spectrometry, chromatography, etc.) in analysis of
water, soil, foodstuffs, and various biological materials
for the determination of heavy metal traces .
The use of CNT for enhancing the sensitivity of
glassy carbon, carbon paste, and impregnated electrodes
to metal ions in methods of anodic [3–9], cathodic ,
and adsorptive stripping voltammetry (AdSV) [11–17]
has been reported. However, these solid-phase sensors are
expensive and require manual mechanical treatment of the
surface between the measurements, so that the analysis
results become fully dependent on the analyst skill.
On the other hand, thick-ﬁ lm technologies of screen
printing are a simple, quick, and cheap method for
mass-scale production of disposable electrochemical
sensors characterized by high accuracy and wide spec-
trum of conﬁ gurations. Single use of screen-printed
electrodes allows contamination of their surface with
reaction products to be prevented, the problem of the
sensor sensitivity loss in the course of operation to be
lifted, and the mechanical regeneration procedure to be
eliminated. The use of such electrodes is economically
advantageous, because they can be used by unskilled
personnel using cheap equipment.
We have found only few data on the use of CNT as
modiﬁ ers for thick-ﬁ lm carbon-containing electrodes
(TFCE) for determining heavy metal ions in solutions
by anodic SV [18–20] and virtually no data on the use
of CNT-modiﬁ ed TFCE in adsortive SV . However,
AdSV is characterized by the lowest limits of detection
(LOD) for heavy metals, on the level of nanograms per
liter, compared to the other kinds of SV and is widely
used for determining trace amounts of elements in aquatic
objects of the environment . Therefore, it is topical to
modify TFCE with multiwalled CNT and to bring the
electrodes based on them into analytical practice.
This study was aimed at developing TFCE based
on multi-walled carbon nanotubes for AdSV and at
evaluating their metrological characteristics for the
determination of iron ions in a model solution as example.
Thick-Film Carbon-Containing Electrodes Modiﬁ ed
with Multi-Walled Carbon Nanotubes in Adsorptive Stripping
Voltammetry of Iron(III)
A. S. Kosykh, N. A. Malakhova, S. Yu. Saraeva, L. I. Kolyadina, A. S. Vokhmintsev,
A. V. Ishchenko, and I. A. Weinstein
Ural Federal University, ul. Mira 19, Yekaterinburg, 620002 Russia
Received April 6, 2015
Abstract—Multi walled carbon nanotubes were used for modiﬁ cation of thick-ﬁ lm carbon-containing electrodes
for adsorptive stripping voltammetry. A complex compound of Fe(III) with pyrocatechol was chosen as model
system. As compared to the electrodes fabricated without using carbon nanotubes, the modiﬁ ed ones have the
recovery close to 100%, 2 times higher sensitivity, and 3 times lower limit of detection. The developed sensors
can be used for quick determination of trace amounts of iron in real objects.