A non-enzymatic hydrogen peroxide sensor based on poly(vinyl alcohol)-multiwalled carbon nanotubes-platinum nanoparticles hybrids modified glassy carbon electrode

Article abstract of DOI:10.1016/j.electacta.2012.03.105

The present work describes an effective strategy to fabricate a highly sensitive and fast response sensor for non-enzymatic hydrogen peroxide (H ₂O₂) determination. Platinum nanoparticles (PtNPs) were electrodeposited onto the multiwalled carbon nanotubes (MWCNTs) which were non-covalently functionalized by freezing-thawing poly(vinyl alcohol) (PVA). The PVA-solubilized MWCNTs could form uniform film on a glassy carbon (GC) electrode, which was considered as a promising support for electrodeposition of metal particles. The PVA-MWCNTs-PtNPs hybrids showed an excellent electrocatalytic activity and offered a significant decrease in the overvoltage for H₂O₂ reduction, as a result of synergic action of PtNPs and MWCNTs. The PVA-MWCNTs-PtNPs hybrids modified sensor exhibited a wide linear range of 0.002-3.8 mM, a remarkable sensitivity of 122.63 μA mM ^-1 cm^-2 at a low potential of 0 mV, a lower detection limit of 0.7 μM at the signal-to-noise ratio of 3, and a fast response time (within 5 s). Additionally, it showed an excellent reproducibility, long-term stability and anti-interference performance. The current work could provide a feasible approach and potential platform to fabricate a variety of non-enzymatic amperometric sensors.

Full text of DOI:10.1016/j.electacta.2012.03.105

Electrochimica Acta 70 (2012) 266–271
Contents lists available at SciVerse ScienceDirect
Electrochimica Acta
journal homepage: www.elsevier.com/locate/electacta
A non-enzymatic hydrogen peroxide sensor based on poly(vinyl
alcohol)–multiwalled carbon nanotubes–platinum nanoparticles hybrids
modified glassy carbon electrode
a
a
a
a
b
b
a,∗
Yuxin Fang , Di Zhang , Xia Qin , Zhiying Miao , Shigehiro Takahashi , Jun-ichi Anzai , Qiang Chen
a
The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Weijin Road No. 94, Tianjin 300071, PR China
Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
b
a r t i c l e i n f o
a b s t r a c t
Article history:
The present work describes an effective strategy to fabricate a highly sensitive and fast response sen-
sor for non-enzymatic hydrogen peroxide (H2O2) determination. Platinum nanoparticles (PtNPs) were
electrodeposited onto the multiwalled carbon nanotubes (MWCNTs) which were non-covalently func-
tionalized by freezing–thawing poly(vinyl alcohol) (PVA). The PVA-solubilized MWCNTs could form
uniform film on a glassy carbon (GC) electrode, which was considered as a promising support for elec-
trodeposition of metal particles. The PVA–MWCNTs–PtNPs hybrids showed an excellent electrocatalytic
activity and offered a significant decrease in the overvoltage for H2O2 reduction, as a result of synergic
action of PtNPs and MWCNTs. The PVA–MWCNTs–PtNPs hybrids modified sensor exhibited a wide linear
range of 0.002–3.8 mM, a remarkable sensitivity of 122.63 ␮A mM cm at a low potential of 0 mV, a
lower detection limit of 0.7 ␮M at the signal-to-noise ratio of 3, and a fast response time (within 5 s).
Additionally, it showed an excellent reproducibility, long-term stability and anti-interference perfor-
mance. The current work could provide a feasible approach and potential platform to fabricate a variety
of non-enzymatic amperometric sensors.
Received 12 January 2012
Received in revised form 13 March 2012
Accepted 15 March 2012
Available online 27 March 2012
Keywords:
Hydrogen peroxide sensor
Platinum nanoparticles
Multiwalled carbon nanotubes
Poly(vinyl alcohol)
−1
−2
Electrodeposition
©
2012 Elsevier Ltd. All rights reserved.
1
. Introduction
properties, rapid electrode kinetics [23–25] and so on, however, the
insolubility of CNTs often limits their application. It is clearly that
acid treated CNTs are hydrophilic and water soluble, but the physi-
cal and chemical properties of CNTs are sometimes greatly changed
[26,27]. Thus, the dispersion of CNTs with suitable biopolymers
seems an attractive way to improve hydrophilicity and solubility
of CNTs.
Poly(vinyl alcohol) (PVA) is a water-soluble, biocompatible,
biodegradable and readily available low-cost synthetic polymer
with good chemical and thermal stability [28]. For these reasons,
PVA has been widely used in medical, cosmetic, and biotechno-
logical fields [29,30]. Physically cross-linked PVA can be obtained
through mild freezing–thawing process and it can act as a suit-
able matrix to immobilize biomaterials [31]. Moreover, PVA can
be considered as a dispersant for non-covalent solubilization of
CNTs in order to avoid the toxicity and elution problem of chemical
scattered reagents [32].
The determination of hydrogen peroxide (H O ) has played
2
2
an important role in biomedical, environmental, and industrial
analyses [1–3]. Many detection techniques have been developed,
including titrimetry [4], spectrometry [5], chemiluminescence [6],
fluorescence [7], and electrochemistry [8–12]. Among these meth-
ods, electrochemical protocol has been widely applied for accurate
determination of H O2 for its high sensitivity, low detection limit
and low cost [13]. During the past few decades, many enzyme-
based biosensors towards H O2 determination have been made.
However, many disadvantages were found, such as the high cost
and instability of enzymes, critical demand on the environmen-
tal condition, and low reproducibility [14]. Considering these facts,
there has been more and more interest in enzyme-free H O2
sensors [15,16], including electrodes modified with noble metals
2
2
2
[
[
17,18], carbon nanotubes [19], metal alloys [20], metal oxides
21,22] and so on.
Recently, nanocomposites have been widely used in preparing
biosensors to improve the performance characteristics. The deco-
ration of CNTs with metal nanoparticles has provided a promising
Carbon nanotubes (CNTs) have attracted tremendous atten-
tion due to their unique advantages including enhanced electronic
way for H O2 detection due to their synergistic effect [33]. To
2
the best of our knowledge, platinum nanoparticles (PtNPs) are
excellent catalysts for H2O2 reduction [34]. Besides, PtNPs are
shown to validly lessen the oxidation/reduction overvoltage in
∗ Corresponding author. Tel.: +86 22 23507273; fax: +86 22 23506122.
E-mail address: qiangchen@nankai.edu.cn (Q. Chen).
0
013-4686/$ – see front matter © 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.electacta.2012.03.105

Y. Fang et al. / Electrochimica Acta 70 (2012) 266–271
267
H O determination [35], which is important to avoid interference
from other co-existing substances. Thus, integration of CNTs with
2.4. Preparation of the PVA–MWCNTs–PtNPs nanocomposites
modified GC electrode
2
2
PtNPs can achieve enhanced performance for H O2 determination.
2
The aim of this paper is to develop a non-enzymatic H O2
The bare GC electrode was polished with 0.3 and 0.05 ␮m
aluminum oxide slurries respectively and ultrasonically cleaned
with ethanol and double distilled water for 10 min to remove
the physically adsorbed substance. The PVA–MWCNTs compos-
ite film modified electrode was prepared by casting 8 ␮L of the
PVA–MWCNTs solution on the surface of GC electrode and dry-
ing under room temperature for 2 h. After that, the PVA–MWCNTs
modified GC electrode was immersed in 30 mL deposition solu-
2
biosensor based on a PVA–MWCNTs–PtNPs nanocomposites mod-
ified glassy carbon (GC) electrode. Initially, the MWCNTs were
successfully dispersed by modifying with cross-linked PVA. The
PVA-functionalized MWCNTs were dispersed homogeneously and
stably in an aqueous solution and were able to form a uniform
film on GC electrode when dried. Subsequently, PtNPs were elec-
trodeposited on the MWCNTs modified GC electrode. The resulting
electrode showed a high catalysis activity in H O reduction due to
tion (0.1 M PBS containing 10 mM K PtCl ) and applied a constant
2
2
2 6
the synergistic effect of MWCNTs and PtNPs.
potential at −200 mV for 300 s to obtain the PVA–MWCNTs–PtNPs
modified GC electrode.
2
. Experimental
3. Results and discussion
2.1. Reagents and materials
3.1. Morphology
Multiwalled carbon nanotubes (MWCNTs) (30–50 nm diam-
After the freezing–thawing treatment of the PVA solution,
eter) were obtained from Institute of Organic Chemistry,
Chinese Academy of Sciences (ChengDu, China). Hydrogen per-
oxide (H O , 30%, v/v aqueous solution) was obtained from
a porous structure arises owing to gelation process [37]. This
hydrophilic PVA can reduce the strong attractive interaction among
the MWCNTs and prevent the aggregation of MWCNTs, resulting in
a high dispersibility and long-term stability of PVA–MWCNTs in
water. The microstructure of the PVA–MWCNTs was investigated
by TEM in Fig. 1 (a, b) under different magnifications. As can be
seen, the MWCNTs were dispersed well by PVA, and from the higher
magnification of TEM image (b), we can clearly see that a core–shell
structure of PVA–MWCNTs. The hard core of MWCNTs in the cen-
ter was enwrapped by the soft shell of grafted polymer PVA with a
thickness of about 5 nm. Fig. 1 (c) shows that the PtNPs have dec-
orated the MWCNTs successfully by electrodeposition. The lattice
structure of PtNPs can be observed clearly under the high magnifi-
cation. The EDX analysis in Fig. 1(d) further reveals that the sample
contains the elements of Pt and C. The peaks of Cu and O in the
spectrum should be from the substrate. These results confirm that
the PtNPs have been coated on the MWCNTs.
2
2
Tianjin Eastern Chemical Reagent Co (China). Potassium Hex-
achloroplatinate (K PtCl ) was purchased from Tianjin Yingda
2
6
Rare Chemical Reagent Co (China). Poly(vinyl alcohol) (PVA)
−1
with a Mw = 30,000–70,000 g mol
(90% hydrolyzed) was pur-
chased from Sigma–Aldrich (USA). Uric acid, ascorbic acid and
acetaminophen were obtained from Tianjin Damao Chemical
Reagent Co. (China). All solutions used in this study were of analyt-
ical grade, and doubly distilled water was used throughout. Freshly
prepared 0.1 M phosphate buffer solution (PBS, pH 7.0), consisting
of Na HPO and KH PO , was used as the supporting electrolyte. All
2
4
2
4
experiments were performed at room temperature, approximately
◦
2
5 C.
2
.2. Apparatus
The electrochemical measurements were carried out in a
3.2. Electrochemical property of the PVA–MWCNTs–PtNPs
conventional one-compartment cell using a 283 Potentiostat-
Galvanostat electrochemical workstation (EG & G PARC with M270
software). A conventional three-electrode system, containing the
PVA–MWCNTs–PtNPs nanohybrids modified GC electrode (3 mm
diameter) as a working electrode, a platinum wire (1 mm diam-
eter) as a counter electrode, and an Ag/AgCl electrode (saturated
with KCl) as a referene electrode, was employed for all electro-
chemical experiments. In steady-state amperometric experiment,
the electrode potential was set at 0 mV under gently magnetic stir-
ring.
hybrids modified GC electrode
Cyclic voltammetry (CV) of ferricyanide system is a common
and convenient method to characterize the real electroactive sur-
face area of the modified electrode [20,38]. CVs of PVA–MWCNTs
(a), PtNPs (b) and PVA–MWCNTs–PtNPs (c) conducted in 0.1 M
3−
KCl containing 10 mM [Fe(CN)6]
PVA–MWCNTs–PtNPs modified GC electrode, well-defined CV with
characteristic oxidation and reduction peaks due to the Fe /Fe
were observed at 302 and 136 mV. The electroactive surface area of
electrode can be estimated for a reversible and diffusion control-
lable process according to the Randles–Sevcik equation [39]:
are shown in Fig. 2. For the
3+
2+
Transmission electron microscopy (TEM) images were obtained
by using Tecnai G2 F20 instrument (Philips Holland) equipped with
an energy-dispersive X-ray spectroscopy (EDX) analyzer.
Ip = 2.69 × 10 AD1/2n3/2v1/2
5
C
(1)
2.3. Dispersion of MWCNTs with PVA
where Ip relates to the redox peak current, A is the area of the elec-
trode (cm ), n represents the number of electron participating in
2
A 0.5 wt% PVA solution was prepared according to the previously
the reaction which is equal to 1, D is the diffusion coefficient of the
−
6
2
−1
reported method [36]. The PVA was dissolved in the aqueous solu-
molecule in solution which is (6.70 ± 0.02) × 10 cm s , C is the
◦
tion with the help of heating at 90 C for 1 h. Then, the solution was
concentration of the probe molecule in the solution which is 10 mM
◦
−1
cooled to room temperature and subsequently was left at −20 C
and v is the scan rate (V s ). According to the above equation, we
◦
for 12 h. After the freezing process, it was put into 4 C refrigerator
can get the approximate value of A. The calculated value of the
electroactive surface area for PVA–MWCNTs–PtNPs modified elec-
trode was about 1.46 and 2.01 times higher than those of the PtNPs
and PVA–MWCNTs modified electrodes, respectively. These results
show that the PVA–MWCNTs–PtNPs film is a more suitable media-
for 12 h. One freezing–thawing cycle can strengthen PVA solution
due to a densification of the macromolecular structure. 1 mg of
MWCNTs was dispersed in 1 mL of 0.5 wt% PVA solution with the
−
1
aid of ultrasonic agitation for 2 h. Thus, the uniform 1 mg mL
PVA–MWCNTs solution was obtained.
tor to transfer the electrons between [Fe(CN)6]3 and the working
−

2
68
Y. Fang et al. / Electrochimica Acta 70 (2012) 266–271
Fig. 1. TEM images of (a, b) dispersion of MWCNTs with PVA under different magnification; (c) PVA–MWCNTs–PtNPs hybrids, and (d) EDX spectrum of the
PVA–MWCNTs–PtNPs.
electrode. In addition, the combination of the advantages of MWC-
NTs (large edge plane/basal plane ratio, enhanced conductivity, and
rapid electrode kinetics) with well dispersive PtNPs (good catalytic
activity and large surface area) possesses bigger electro-active sur-
face areas, which facilitates the adsorption of detection molecules.
Fig. 3 shows the CVs of the PVA–MWCNTs (a), PtNPs (b) and
PVA–MWCNTs–PtNPs (c) modified electrodes in 0.5 M H SO at
2
4
−
1
the scan rate of 50 mV s . For the PVA–MWCNTs (a) modified
electrode, only one set of redox peaks with potential of about
4
50 mV can be observed. For the PtNPs (b) modified electrode,
there are two pairs of hydrogen adsorption/desorption peaks in
the potential range of 100 to −200 mV, together with the dou-
ble layer potential region from 100 to 400 mV, and a signature
peak for oxide formation at higher than 600 mV, as well as strip-
ping peak centered at approximately 500 mV, exhibiting the typical
features of polycrystalline platinum [40]. On the other hand, the
PVA–MWCNTs–PtNPs hybrids (c) modified electrode exhibited
a sharp increase in the peak current with unchanged relevant
potentials, indicating much higher electrocatalytic activity of the
PVA–MWCNTs–PtNPs hybrids modified electrode. Comparing with
the PtNPs electrode, the enhanced activity in the formal potentials
of PVA–MWCNTs–PtNPs electrode could be due to the introduction
Fig. 2. Cyclic volatmmograms of (a) PVA–MWCNTs, (b) PtNPs, (c)
PVA–MWCNTs–PtNPs modified GC electrodes recorded in 0.1 M KCl aqueous
3−
−1
containing 10 mM [Fe(CN)6] . Scan rate: 50 mV s .

Y. Fang et al. / Electrochimica Acta 70 (2012) 266–271
269
Fig. 3. Cyclic voltammograms of PVA–MWCNTs (a), PtNPs (b) and
−
1
PVA–MWCNTs–PtNPs hybrids (c) in 0.5 M H2SO4 with the scan rate of 50 mV s
.
Fig. 5. Cyclic voltammograms of PVA–MWCNTs (a), PtNPs (b), and
PVA–MWCNTs–PtNPs (c) modified GC electrodes in PBS containing 5 mM
H2O2.
of MWCNTs, which resulted in amplifying the peak current of the
PtNPs. The phenomenon could be ascribed to the synergistic effect
of the fast electron-transfer ability of MWCNTs and excellent catal-
ysis of PtNPs.
deposition time of 5 min and the K PtCl6 concentration of 10 mM
were selected as the optimized conditions in this work.
2
3
.3. Influence of the amount of the deposited PtNPs on
3
.4. Electrochemical performance of PVA–MWCNTs–PtNPs
electrocatalytic characteristics of the PVA–MWCNTs–PtNPs
electrode towards H O
towards hydrogen peroxide
2
2
The electrochemical performance of the PVA–MWCNTs–PtNPs
electrode was investigated by detecting H O . Fig. 5 shows the
The PtNPs deposited on the surface of MWCNTs can enhance
the electrocatalytic activity and provide a large active surface area
for H O determination, so the amount of the PtNPs loading on the
MWCNTs can directly affect the electroactivity of the as-prepared
sensor. To optimize the amount of the PtNPs, the electrodeposition
2
2
CVs of the electrodes between −300 and 800 mV versus Ag/AgCl
2
2
−1
at the scan rate of 50 mV s . For comparison, CVs for the
PVA–MWCNT (a) and PtNPs (b) modified electrodes were also
shown. For the PVA–MWCNTs modified electrode (a), nearly no
redox activity is observed for H O . In contrast, the PtNPs (b) and
time and concentration of precursors (K PtCl ) were investigated.
2
6
2
2
As shown in Fig. 4a, the current response increased with increas-
ing electrodeposition time from 1 to 5 min to reach the maximum
and decreased thereafter. And Fig. 4b also presents similar phe-
nomenon. The current response enhanced as the concentration
of K PtCl increased up to 10 mM. For higher concentration than
PVA–MWCNTs–PtNPs (c) modified electrodes changed dramati-
cally with obvious increases of the reduction (cathodic) current
centered around 0 mV. This observation is a clear evidence of
electrocatalysis of PtNPs. The potential-independent current is
2
6
explained [34] by assuming that the H O2 reduction is initiated
2
1
0 mM, a reduction of current response is observed. These may
by the dissociative adsorption of H O2
2
be associated with the block of the electron transfer and decrease
of the real surface area of the electrode resulting from the depo-
sition of excessive PtNPs on the MWCNTs surface. Therefore, the
k
1
2
Pt + H O −→ 2Pt − OH
(2)
2
2
Fig. 4. Effect of electrodeposition time (a) and concentration of precursors (K2PtCl6) (b) on steady-state response current of PVA–MWCNTs–PtNPs electrode upon addition
of 1 mM H2O2 into the stirring 0.1 M PBS (pH 7.0). Applied potential: 0 mV.

2
70
Y. Fang et al. / Electrochimica Acta 70 (2012) 266–271
Table 1
Comparison of performance of various H2O2 sensors.
Detection limit (␮mol L−1)
Sensitivity (␮A mM cm
−1
−2
)
Reference
Electrode
Applied potential (mV)
Se/Pt
GO/MnO2
AgNPs/CNTs
Fe3O4/Ag
GO/AuNPs/CS
AgNPs/DNA
AuNWs assembling spheres
PVA–MWCNTs–PtNPs
0
−300
−450
−500
−200
−400
−200
0
3.1
0.8
1.6
1.2
–
1.7
1.2
0.7
39.89
38.2
–
–
99.5
–
[18]
[43]
[45]
[48]
[42]
[10]
[17]
This work
–
122.63
followed by electrochemical reduction of the resultant Pt–OH
The inset of Fig. 6 shows the calibration curve of the H O2
2
sensor, the linear response was proportional to the H O2 con-
2
k
2
centration in the range from 0.002 to 3.8 mM with a correlation
4
Pt − OH−→ 4Pt + O + 2H O
(3)
2
2
−
1
−2
,
coefficient of 0.991. The sensitivity was 122.63 ␮A mM cm
which was much higher than the previously reported values,
above reactions represent catalytic decomposition of H O2 on
2
−
1
−2
−1
−2
[43] and
PtNPs.
being 39.89 ␮A mM cm
[18], 38.2 ␮A mM cm
−2
20.08 ␮A mM cm [44]. In addition, the detection limit was
−
1
And for the PVA–MWCNTs–PtNPs (c) modified electrode, the
highest current signal with lower reduction overvoltage are
observed, which means that the PVA–MWCNTs–PtNPs modified
0.7 ␮M at the signal-to-noise ratio of 3, which was lower than
those reported for silver nanoparticles/CNTs modified GC electrode
(1.6 ␮M) [45], enzyme-coupled PtNPs/polyaniline modified elec-
trode (2.8 ␮M) [46], macroporous Au-/nPts electrode (50 ␮M) [47],
Fe O –Ag hybrids submicrosphere modified electrode (1.2 ␮M)
electrode exhibits the best electrocatalytic activity towards H O2
2
among those. It may be because that the MWCNTs used here
as a supporting matrix could disperse PtNPs well, preventing
them from aggregation and thus making them exhibit large active
3
4
[48], and Se/Pt nanocomposites modified electrode (3.1 ␮M) [18].
sites and easier to contact with H O2 for the electrocatalytic
We have summarized various H O2 sensors in Table 1 with
2
2
process.
respect to the applied potential, the detection limit and the sen-
sitivity. It can be seen that the proposed PVA–MWCNTs–PtNPs
electrode shows a good performance than other non-enzymatic
Since PVA–MWCNTs–PtNPs (c) exhibits the highest response
current at the electric potential of 0 mV, we choose 0 mV as the
work potential for detection of H O . In contrast to other H O
H O sensors. This further reveals the excellent performance of
2 2
2
2
2
2
amperometric sensors of pervious literature reports [17,41,42], the
applied potential for the PVA–MWCNTs–PtNPs modified electrode
is much smaller. At such a low potential, the background current
decreases and the response of common interference materials can
be minimized.
PVA–MWCNTs–PtNPs as a promising material in H O2 detection.
2
Real samples analysis has also been investigated. As shown in
Table 2, the sensor was applied to the determination of H O in dis-
2
2
infected fetal bovine serum (FBS). It can be seen that the recoveries
are between 95% and 106.5%, indicating that the proposed method
can be applied in real samples determination.
Fig.
6
displays the amperometric responses of the
PVA–MWCNTs–PtNPs nanocomposites modified GC electrode
upon successive addition of H O2 into the stirring PBS (pH 7.0)
2
3
.5. Selectivity reproducibility and stability of the modified
under the applied potential of 0 mV. When the H O2 of certain
2
electrode
concentration was added into the PBS solution, the reduction
current increased rapidly to reach a steady-state value within 5 s
In real samples, the co-existing electroactive compounds such
(
achieving 95% of the steady-state current).
as AA, UA and AP can affect the sensor response. The level of AA,
UA and AP in human blood is approximately 0.125 mM, 0.33 mM
and 0.13 mM, respectively, the selectivity and anti-interference
of the present H O2 biosensor were studied by comparing the
2
amperometric responses of these electroactive species (0.15 mM
AA, 0.5 mM UA and 0.15 mM AP) and H O2 (1 mM) at the poten-
2
tial of 0 mV. Fig. 7 shows that the amperometric responses of
the PVA–MWCNTs–PtNPs electrode upon subsequent additions of
1
mM H O , 0.5 mM UA, 0.15 mM AP, 0.15 mM AA and 1 mM H O .
2
2
2
2
It’s clearly seen that the as-prepared electrode exhibits excellent
selectivity for H O , and the responses caused by AA, UA and AP
2
2
could be negligible. The good performance of anti-interference is
mainly due to the low working potential of 0 mV.
Table 2
Determination of H2O2 in disinfected FBS samples.
Samplea
Added
mmol L−1)
Found
(mmol L
R.S.D.
(%, n = 6)
Recovery
(%)
−1
(
)
1
2
3
0.5
1
2
0.51
0.95
2.13
3.3
4.5
4.2
102
95
106.5
Fig. 6. Amperometric responses of the PVA–MWCNTs–PtNPs modified GC electrode
upon successive addition of H2O2 into the stirring 0.1 M PBS (pH 7.0). Applied poten-
tial: 0 mV. Inset: linear calibration curve.
a
The samples were diluted 100 times, average of six measurements.

Y. Fang et al. / Electrochimica Acta 70 (2012) 266–271
271
References
[
[
1] X.B. Lu, J.H. Zhou, W. Lu, Q. Liu, J.H. Li, Biosens. Bioelectron. 23 (2008) 1236.
2] C.G. Tsiafoulis, P.N. Trikalitis, M.I. Prodromidis, Electrochem. Commun. 7 (2005)
1398.
[
[
[
[
[
[
[
3] X.L. Luo, J.J. Xu, W. Zhao, H.Y. Chen, Biosens. Bioelectron. 19 (2004) 1295.
4] E.C. Hurdis, J. Romeyn, Anal. Chem. 26 (1954) 320.
5] C. Matsubara, N. Kawamoto, K. Takamura, Analyst 117 (1992) 1781.
6] S. Hanaoka, J.M. Lin, M. Yamada, Anal. Chim. Acta 426 (2001) 57.
7] L.S. Zhang, G.T.F. Wong, Talanta 48 (1999) 1031.
8] M.G. Garguilo, N. Huynh, A. Proctor, A.C. Michael, Anal. Chem. 65 (1993) 523.
9] Y. Xiao, H.X. Ju, H.Y. Chen, Anal. Chim. Acta 391 (1999) 299.
[
[
[
10] K. Cui, Y.H. Song, Y. Yao, Z.Z. Huang, L. Wang, Electrochem. Commun. 10 (2008)
63.
11] T. Hoshi, H. Saiki, S. Kuwazawa, Y. Kobayashi, J. Anzai, Anal. Sci. 16 (2000)
009.
12] T. Hoshi, H. Saiki, S. Kuwazawa, C. Tsuchiya, J. Anzai, Anal. Chem. 73 (2001)
310.
6
1
5
[
[
13] Y.Y. Wang, X.J. Chen, J.J. Zhu, Electrochem. Commun. 11 (2009) 323.
14] B. Zhao, Z.R. Liu, Z.L. Liu, G.X. Liu, Z. Li, J.X. Wang, X.T. Dong, Electrochem.
Commun. 11 (2009) 1707.
[
15] F.G. Xu, Y.J. Sun, Y. Zhang, Y. Shi, Z.W. Wen, Z. Li, Electrochem. Commun. 13
(
2011) 1131.
[
[
[
[
[
[
[
16] B. Wang, X. Du, M. Wang, W. Gong, J. Anzai, Electroanalysis 20 (2008) 1028.
17] S.J. Guo, D. Wen, S.J. Dong, E.K. Wang, Talanta 77 (2009) 1510.
18] Y. Li, J.J. Zhang, J. Xuan, L.P. Jiang, J.J. Zhu, Electrochem. Commun. 12 (2010) 777.
19] F. Kurusu, S. Koide, I. Karube, M. Gotoh, Anal. Lett. 39 (2006) 903.
20] Y. Li, R. Yuan, Y.Q. Chai, Z.J. Song, Electrochim. Acta 56 (2011) 6715.
21] L. Zhang, Y.H. Ni, X.H. Wang, G.C. Zhao, Talanta 82 (2010) 196.
Fig. 7. Amperometric responses of the PVA–MWCNTs–PtNPs electrode upon sub-
sequent additions of 1 mM H2O2, 0.5 mM UA, 0.15 mM AP, 0.15 mM AA and 1 mM
H2O2 at 0 mV versus Ag/AgCl.
22] L. Zhang, H. Li, Y.H. Ni, J. Li, K.M. Liao, G.C. Zhao, Electrochem. Commun. 11
In addition, the reproducibility and long-term stability are also
important parameters to evaluate the ability of sensor. The device-
to-device reproducibility was evaluated from the response to 5 mM
(
2009) 812.
[23] G.D. Liu, Y.H. Lin, Electrochem. Commun. 8 (2006) 251.
[
24] Z. Song, J.D. Huang, B.Y. Wu, H.B. Shi, J. Anzai, Q. Chen, Sens. Actuators B 115
2006) 626.
(
H O at five electrodes independently, and the relative standard
2
2
[
25] J.D. Huang, Z. Song, J. Li, Y. Yang, H.B. Shi, B.Y. Wu, J. Anzai, T. Osa, Q. Chen,
Mater. Sci. Eng. C 27 (2007) 29.
deviation was calculated to 3.8%. Besides, the long-term stability
was tested by measuring the response to 5 mM H O solution every
[26] K. Dai, L.Y. Shi, D.S. Zhang, J.H. Fang, Chem. Eng. Sci. 61 (2006) 428.
2
2
[
27] A. Magrez, S. Kasas, V. Salicio, N. Pasquier, J.W. Seo, M. Celio, S. Catsicas, B.
Schwaller, L. Forro, Nano Lett. 6 (2006) 1121.
day for one month. The as-synthesized electrode remained 87% of
its initial current response for H O2 after one month. Thus, the
2
[28] S. Majumdar, B. Adhikari, Sens. Actuators B 114 (2006) 747.
[29] J.W. Di, S.P. Bi, M. Zhang, Biosens. Bioelectron. 19 (2004) 1479.
PVA–MWCNTs–PtNPs electrode exhibited an acceptable long-term
stability.
[
[
[
[
30] E. Chiellini, A. Corti, S. D’Antone, R. Solaro, Prog. Polym. Sci. 28 (2003) 963.
31] K.Y. Lee, D.J. Mooney, Chem. Rev. 101 (2001) 1869.
32] Y.C. Tsai, J.D. Huang, C.C. Chiu, Biosens. Bioelectron. 22 (2007) 3051.
33] M.H. Yang, Y.H. Yang, Y.L. Liu, G.L. Shen, R.Q. Yu, Biosens. Bioelectron. 21 (2006)
4
. Conclusions
1125.
[
34] Y. Mukouyama, S. Nakanishi, H. Konishi, K. Karasumi, Y. Nakato, Phys. Chem.
Chem. Phys. 3 (2001) 3284.
In this study, PtNPs were electrodeposited on the MWC-
NTs which were dispersed uniformly by PVA obtained via a
freezing–thawing process. We found that the cross-linked PVA
demonstrated an efficient ability to avoid the aggregation of MWC-
NTs. And the decoration of PtNPs onto the MWCNTs could result in
[35] D. Ravi Shankaran, N. Ueheara, T. Kato, Biosens. Bioelectron. 18 (2003) 721.
[
[
[
36] Y.C. Tsai, J.D. Huang, Electrochem. Commun. 8 (2006) 956.
37] V.I. Lozinsky, M.F. Plieva, Enzyme Microb. Technol. 23 (1998) 227.
38] H.C. Wang, X.S. Wang, X.Q. Zhang, X. Qin, Z.X. Zhao, Z.Y. Miao, N. Huang, Q.
Chen, Biosens. Bioelectron. 25 (2009) 142.
39] A.J. Bard, L.R. Faulkner, Electrochemical Methods: Fundamentals and Applica-
tions, 2nd ed., John Wiley and Sons, NY, 2001.
[
significantly enhanced response towards H O2 reduction. Besides
2
that, the resulting H O2 sensor exhibited high sensitivity, wide
2
[40] V. Stamenkovic, N.M. Markovic, P.N. Ross, J. Electroanal. Chem. 500 (2001)
44.
linear range, low detection limit, good reproducibility and long-
term stability. This work presented a feasible approach for future
research in biosensors and other surface functionalizing.
[
[
41] F.L. Qu, M.H. Yang, G.L. Shen, R.Q. Yu, Biosens. Bioelectron. 22 (2007) 1749.
42] C.S. Shan, H.F. Yang, D.X. Han, Q.X. Zhang, A. Ivaska, L. Niu, Biosens. Bioelectron.
2
5 (2010) 1070.
43] L.M. Li, Z.F. Du, S. Liu, Q.Y. Hao, Y.G. Wang, Q.H. Li, T.H. Wang, Talanta 82 (2010)
637.
[
[
1
Acknowledgments
44] W. Zhao, H.C. Wang, X. Qin, X.S. Wang, Z.X. Zhao, Z.Y. Miao, L.L. Chen, M.M.
Shan, Y.X. Fang, Q. Chen, Talanta 80 (2009) 1029.
The financial supports from National Natural Science Founda-
tion of China (Grant No. 81127001) and Science and Technology
Plan Project of Tianjin (Grant Nos. 11ZCGHHZ01300 and 11ZCK-
FSY07000) are acknowledged. And the present work is also
supported in part by Goho Life Science International Fund at 2011.
[45] Y. Shi, Z.L. Liu, B. Zhao, Y.J. Sun, F.G. Xu, Y. Zhang, Z.W. Wen, H.B. Yang, Z. Li, J.
Electroanal. Chem. 656 (2011) 29.
[
46] S.H. Chen, P. Fu, B. Yin, R. Yuan, Y.Q. Chai, Y. Xiang, Bioprocess. Biosyst. Eng. 34
2011) 711.
[47] Y.J. Lee, J.Y. Park, Y.H. Kim, J.W. Ko, Curr. Appl. Phys. 11 (2011) 211.
48] Z.L. Liu, B. Zhao, Y. Shi, C.L. Guo, H.B. Yang, Z. Li, Talanta 81 (2010) 1650.
(
[