Sensors
and
Actuators
B
177 (2013) 412–
418
Contents
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at
SciVerse
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Sensors
and
Actuators
B:
Chemical
journa
l
h
o
me
pa
ge:
www.elsevier.com/locate/snb
A
graphene
oxide–mesoporous
MnO
2
nanocomposite
modified
glassy
carbon
electrode
as
a
novel
and
efficient
voltammetric
sensor
for
simultaneous
determination
of
hydroquinone
and
catechol
Tian
Gan
∗
,
Junyong
Sun,
Kejing
Huang,
Li
Song,
Youmei
Li
College
of
Chemistry
and
Chemical
Engineering,
Xinyang
Normal
University,
Xinyang,
464000,
PR
China
a
r
t
i
c
l
e
i
n
f
o
Article
history:
Received
20
September
2012
Received
in
revised
form
4
November
2012
Accepted
12
November
2012
Available online 22 November 2012
Keywords:
Graphene
oxide
Mesoporous
MnO
2
Hydroquinone
Catechol
Electrochemical
sensor
Simultaneous
determination
a
b
s
t
r
a
c
t
A
new
facile
preparation
method
of
graphene
oxide–mesoporous
MnO
2
(GO–MnO
2
)
nanocomplex
was
developed
here.
The
GO–MnO
2
was
used
as
a
new
electrode
material
for
the
fabrication
of
voltammetric
sensor
for
sensitive
simultaneous
determination
of
hydroquinone
(HQ)
and
catechol
(CC),
which
exhib-
ited
significantly
decreased
peak-to-peak
separations
of
ca.
34
and
36
mV
for
HQ
and
CC,
respectively
between
oxidation
and
reduction
waves
in
cyclic
voltammetry.
In
differential
pulse
voltammetric
mea-
surements,
the
GO–MnO
2
based
sensor
could
separate
the
oxidation
peak
potentials
of
HQ
and
CC
by
about
115
mV
though
the
bare
electrode
gave
a
single
broad
response,
which
was
related
to
the
higher
surface
area
and
catalytic
ability
of
GO–MnO
2
.
The
oxidation
peak
current
of
HQ
was
linear
over
the
range
from
0.01
to
0.7
M
in
the
presence
of
0.1
M
CC,
and
the
oxidation
peak
current
of
CC
was
linear
over
the
range
from
0.03
to
1.0
M
in
the
presence
of
0.13
M
HQ.
The
detection
limits
(S/N
=
3)
for
HQ
and
CC
were
7.0
and
10.0
nM,
respectively.
The
proposed
sensor
was
successfully
applied
to
the
simultaneous
determination
of
HQ
and
CC
in
artificial
wastewater
samples.
© 2012 Elsevier B.V. All rights reserved.
1.
Introduction
Graphene
oxide
(GO),
a
single
layer
of
graphite
oxide,
was
first
produced
by
treating
graphite
with
strong
aqueous
oxidiz-
ing
agents
[1].
GO
has
shown
intensive
promising
applications
in
electronic
devices
[2],
composites
[3]
and
electroanalysis
[4,5]
partially
because
of
its
good
solution-processibility
and
ease
of
post-functionalization.
Recently,
inorganic
nanoparticles,
such
as
metal
[6,7],
metal
oxide
[8,9],
metal
hydroxide
[10]
and
metal
sul-
fide
[11]
have
been
utilized
to
disperse
on
graphene
nanosheets
to
broaden
the
horizons
for
the
use
of
graphene.
The
syner-
getic
effects
between
graphene
and
the
inorganic
particles
make
the
graphene-supported
hybrids
exhibit
excellent
properties
and
improved
functionalities.
Recently,
highly
ordered
mesoporous
semiconductor
metal
oxides
with
the
intriguing
features
of
easy
recover,
large
surface
area,
high
pore
volume,
ordered
porous
channels,
uniform
and
tun-
able
pore
structure,
and
great
diversity
in
surface
functionalization
[12]
have
attracted
great
interest,
and
can
be
used
as
catalysts
[13],
catalysts
supports
[14],
adsorbents
[15]
and
nanoreactor
[16].
Among
them,
manganese
dioxide
(MnO
2
)
has
been
intensively
investigated
because
it
has
the
advantages
of
low-cost,
abundance
∗
Corresponding
author.
Tel.:
+86
376
6390702;
fax:
+86
376
6390597.
E-mail
address:
gantianxynu@163.com (T.
Gan).
and
non-toxicity
compared
to
cobalt,
nickel
and
vanadium
[17,18].
Composite
electrodes
based
on
the
MnO
2
-modified
carbon
powder
proved
to
be
useful
for
detection
of
H
2
O
2
,
ascorbic
acid
and
nitrite
ions
[19].
However,
a
catalyst
support
is
usually
needed
to
realize
an
optimized
utilization
of
active
sites.
The
simultaneous
determination
of
hydroquinone
(1,4-
dihydroxy-benzene,
HQ)
and
catechol
(1,2-dihydroxybenzene,
CC)
is
an
interesting
subject
in
electroanalysis
because
they
have
similar
structures
and
properties,
and
they
usually
coexist
in
environmental
samples
as
pollutants
with
high
toxicity
[20].
At
present,
the
methods
in
the
literature
for
the
HQ
and
CC
simul-
taneous
determination
[21]
are
made
after
previous
chemical
or
physical
separation,
and
the
time,
wastes
and
reagent
consuming
are
generally
high
in
these
analyses.
Therefore,
the
electrochemical
methods
[22–29]
with
the
merits
of
reduced
costs,
automatic
and
fast
analysis,
high
sensitivity
and
selectivity,
and
no
need
for
previous
separations
have
triggered
enormous
research
activities.
In
this
paper,
we
present
an
easy
and
general
method
to
prepare
GO–MnO
2
hybrid
by
simple
grinding
method
using
GO
and
meso-
porous
MnO
2
as
starting
materials.
The
GO–MnO
2
hybrid
was
demonstrated
to
have
great
potential
as
effective
material
for
the
fabrication
of
electrochemical
sensor
for
sensitive
simultaneous
determination
of
HQ
and
CC
with
anodic
peak
potential
of
115
mV,
due
to
their
high
adsorption
capacity
and
enhanced
catalytic
activ-
ity.
The
detection
limits
(S/N
=
3)
for
HQ
and
CC
at
this
sensor
were
7.0
and
10.0
nM,
respectively,
which
were
lower
than
that
on
the
0925-4005/$
–
see
front
matter ©
2012 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.snb.2012.11.033