Preparation of β-cyclodextrin functionalized reduced graphene oxide: Application for electrochemical determination of paracetamol

Article abstract of DOI:10.1039/c5ra12520k

β-Cyclodextrin functionalized reduced graphene oxide (β-CD/RGO) was successfully prepared using a simple wet chemical method. The β-CD/RGO nanohybrid was characterized by UV-vis spectroscopy, FTIR, Raman spectroscopy, TEM and SEM. The results confirmed that β-CD had effectively covered the RGO surface. The β-CD/RGO nanohybrid modified glassy carbon electrode was employed for the sensitive electrochemical determination of paracetamol. Cyclic voltammetry measurements indicated that β-CD/RGO could significantly enhance the electrochemical response of paracetamol due to the outstanding electronic properties of RGO sheets and the high supramolecular recognition and enrichment capability of β-CD. The experimental factors were investigated and optimized. Under optimized conditions, the amperometric oxidation currents of paracetamol were linearly proportional to the concentration in the range of 0.01 to 0.8 mM with a detection limit of 2.3 μM (S/N = 3). Furthermore, the proposed sensor exhibited an excellent anti-interference property and acceptable reproducibility.

Full text of DOI:10.1039/c5ra12520k

View Article Online
View Journal
RSC Advances
This article can be cited before page numbers have been issued, to do this please use: L. FU, G. Lai and
A. Yu, RSC Adv., 2015, DOI: 10.1039/C5RA12520K.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. This Accepted Manuscript will be replaced by the edited,
formatted and paginated article as soon as this is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the Ethical guidelines still
apply. In no event shall the Royal Society of Chemistry be held
responsible for any errors or omissions in this Accepted Manuscript
or any consequences arising from the use of any information it
contains.
www.rsc.org/advances

Page 1 of 7
RSC Advances
View Article Online
DOI: 10.1039/C5RA12520K
Preparation of β-cyclodextrin functionalized reduced
graphene oxide: Application for electrochemical
determination of paracetamol
Li Fu, Guosong Lai and Aimin Yu*
A sensitive electrochemical sensor of paracetamol was developed based on
graphene oxide modified electrode.
β-CD/reduced

View Article Online
DOI: 10.1039/C5RA12520K
RSC Advances
Page 2 of 7
PCCP
RSCPublishing
ARTICLE
Preparation of β-cyclodextrin functionalized reduced
graphene oxide: Application for electrochemical
determination of paracetamol
Cite this: DOI: 10.1039/x0xx00000x
Li Fua, Guosong Laib and Aimin Yu a,b,
*
Received 00th January 2012,
Accepted 00th January 2012
β-cyclodextrin functionalized reduced graphene oxide (β-CD/RGO) was successfully prepared
using a simple wet chemical method. The β-CD/RGO nanohybrid was characterized by UV-vis
spectroscopy, FTIR, Raman spectroscopy and SEM. The results confirmed that β-CD had been
effectively covered on the RGO surface. The β-CD/RGO nanohybrid modified glassy carbon
electrode was employed for the sensitive electrochemical determination of paracetamol. Cyclic
voltammetry measurements indicated that β-CD/RGO could significantly enhance the
electrochemical response of paracetamol due to the outstanding electronic properties of RGO
sheets and the high supramolecular recognition and enrichment capability of β-CD. The
experimental factors were investigated and optimized. Under optimized conditions, the
amperometric oxidation currents of paracetamol were linearly proportional to the concentration
in the range of 0.01 to 0.8 0mM with a detection limit of 2.3 μM (S/N = 3). Furthermore, the
proposed sensor exhibited an excellent anti-interference property and acceptable
reproducibility.
DOI: 10.1039/x0xx00000x
www.rsc.org/
sheet of sp2 hybridized carbon, have attracted tremendous
1. Introduction
attention since physicist Geim and co-workers isolated in
22
2004.21,
The graphene materials possess extraordinary
Paracetamol (acetaminophen, N-acetyl-p-aminophenol) is an
effective antipyretic and analgesic drug used for the widespread
mechanical strength, large specific surface area and high
conductivity. It has showed great performance in developing
various electrochemical sensors.23-27 However, one severe
problem that may limit its applications is most graphene used in
electrode modification is reduced graphene oxide (RGO) which
is reduced from graphene oxide (GO). RGO is prone to
irreversible spontaneous agglomeration in water, which highly
restricts its application in water based systems and also further
modification with other compounds. To overcome this problem,
poly(diallyl dimethyl ammonium chloride) (PDDA) has been
used as a dispersive reagent for stopping RGO sheets
agglomeration. Study showed that the PDDA functionalized
RGO exhibits excellent conductivity, biocompatibility and
solubility.28, 29
relief of pain and fever, which have been recognized as an
2
alternative to aspirin.1,
Although paracetamol shows no
propensity to be addictive for long time use and no side effects
in the proper therapeutic dose,3 the overdose of paracetamol can
produce toxic metabolite accumulation leading to liver and
kidney damage.4, 5 Thus, it is very valuable to develop a simple,
inexpensive, rapid, sensitive and precise determination method
for the general public health purposes. To date, several
analytical
methods
such
as
spectrophotometry,6
spectrofluorometry,7 high performance liquid chromatography,8
titrimetry,9 chemiluminescence,10 gas chromatography,11
capillary electrophoresis12 and electrochemical methods1, 13-18
have been studied for the determination of paracetamol. Among
them, electrochemical technique is more attractive compared
with other methods due to the relatively simple sample
preparation, fast response and low detection limits.
Meanwhile, β-Cyclodextrin (β-CD) is
a
cyclic
In order to improve the performance of traditional
electrodes, many kinds of materials such as carbon materials,13-
oligosaccharide consisting of seven glucose units and being
toroidal in shape with a hydrophobic inner cavity and a
hydrophilic exterior. Due to its unique ability to form stable
host–guest inclusion complexes, it has been immobilized on
electrodes to interact with many organic, inorganic and
17
noble metal nanoparticles,1, 19, 20 conductive polymers17 and
metal oxides18 have been extensively employed as
electrocatalysts for the construction of paracetamol sensors.
Among various carbon materials, graphene, a two-dimensional
This journal is © The Royal Society of Chemistry 2013
J. Name., 2013, 00, 1-3 | 1

View Article Online
DOI: 10.1039/C5RA12520K
Page 3 of 7
ARTICLE
RSC Advances
Journal Name
biological guest molecules.30-32 Till now, β-CD has been A glassy carbon electrode (GCE) was polished by 0.3 and 0.05
applied in sensors for detecting various molecules such as μm alumina slurry followed by thoroughly rinsing with ethanol
methyl
parathion,33
doxorubicin,
methotrexate,34
4- and water. For the electrode surface modification, 5 μL of as-
prepared β-CD/RGO dispersion (0.5 mg/mL) was dropped onto
nitrophenol,35 dopamine36 and imidacloprid.37
We believe the integration of β-CD with PDDA the GCE surface and dried at room temperature.
functionalized graphene might possess both unique properties
All electrochemical measurements were performed on a
together and service as a promising composite material for CHI430a electrochemical workstation (USA) at room
sensing purpose. Herein, we report a wet chemical strategy to temperature. A conventional three electrode system containing
synthesize the β-CD/RGO nanohybrid with excellent dispersity. a modified GCE as working electrode, a platinum wire as
The obtained β-CD/RGO nanohybrid is characterized by FTIR, auxiliary electrode and a Ag/AgCl (3M KCl) electrode as
UV-vis spectroscopy and Raman spectroscopy. The composite reference electrode was used throughout the electrochemical
is then modified onto an electrode for the development a experiments.
sensitive electrochemical sensor for the measurement of
paracetamol. The electrochemical enhancement of paracetamol 3. Results and discussion
at β-CD/RGO modified electrode due to the synergic effect of
graphene and β-CD is studied in detail.
3.1 Characterization of β-CD/RGO nanohybrid
Fig. 1 illustrates the procedure for the synthesis of β-CD/RGO
nanohybrid and the sensing mechanism for guest molecules
(paracetamol). Briefly, the homogeneous GO dispersion was
mixed with β-CD and PDDA. GO was then reduced by
hydrazine under an alkaline condition. The introduction of
PDDA was to improve the dispersity of β-CD/RGO nanohybrid
after the reduction of GO. The resulting dispersion remains
stable for more than one month.
2. Experimental
2.1 Chemicals
Poly(diallyl dimethyl ammonium chloride) (PDDA, 20 wt.%,
Mw = 100 000-200 000 g/mol), hydrazine hydrate, paracetamol,
uric acid (99%), L-ascorbic acid (99%), 3-hydroxytyramine
hydrochloride (DA), and glucose were purchased from Sigma-
Aldrich. Graphene oxide (GO) powder was purchased from
JCNANO, INC. β-cyclodextrin (β-CD) was purchased from
SANGHAIHUSHI. All other chemicals used were analytical
grade reagents without further purification. Phosphate buffer
solution (PBS) was prepared by mixing 0.2 M KH2PO4 and
K2HPO4 solution to appropriate pH. Milli-Q water (18.2 MΩ
cm) was used throughout the experiments.
The obtained nanohybrid was confirmed by the UV-vis
spectroscopy. Fig. 2A displays the UV-vis spectra of GO and β-
CD/RGO dispersions. It can be clearly seen that GO exhibits a
characteristic absorption peak at 227 nm, corresponding to the
π→π* transition of the C
═
C bonds.38 After the chemical
reduction, this peak gradually red-shifted to 264 nm, suggesting
the restoration of sp2-carbon network.
2.2 Preparation of β-CD/RGO nanohybrid
In a typical synthesis of β-CD/RGO nanohybrid, 10 mg GO
was firstly dispersed in 10 mL water facilitated by sonication.
Then, 1 mL PDDA and 0.5 g β-CD were successively added to
the GO dispersion. After being vigorously stirred for 2 h, 500
μL ammonia and 300 μL hydrazine were added into the
solution. The mixture was then heated to 90°C and maintained
at the temperature for 4 h. Finally, a black precipitation was
collected by centrifugation followed by three times water
washing. RGO sample was also synthesized by similar method
without adding PDDA and β-CD.
2.3 Characterization
The surface functional groups present on the samples were
analyzed by Fourier transform infrared spectroscopy (FTIR,
Nicolet iS5, Thermo Scientific, USA). The optical
characterizations were obtained by UV-vis spectrophotometer
in the wavelength range from 190 to 800 nm. The surface
morphology of the samples was analyzed by a field emission
scanning electron microscope (FESEM, ZEISS SUPRA 40VP).
Raman spectroscopy was performed at room temperature using
a Raman microscope (Renishaw, inVia) with 514 nm laser light.
Fig. 1 Schematic diagram of the formation of β-CD/RGO
which was used for sensing paracetamol molecules via host-
guest interaction.
Raman spectroscopy was used to characterize the structural
changes from GO to β-CD/RGO. As shown in Fig. 2B, the
spectrum of GO has two bands at 1592 and 1350 cm–1,
corresponding to the graphite (G) and diamondoid (D) bands,
2.4 Electrochemical detection of paracetamol
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012

View Article Online
DOI: 10.1039/C5RA12520K
RSC Advances
Page 4 of 7
Journal Name
ARTICLE
respectively. The G band is a characteristic feature of graphitic Fig. 3 FTIR spectra of GO, β-CD, PDDA and β-CD/RGO.
carbon layers corresponding to the tangential vibration of the
carbon atoms, whereas the D band is a typical sign of the
The morphology of the GO, RGO and β-CD/RGO were
presence of defective graphitic carbon.39 The intensity ratio of observed under SEM characterization. As shown in Fig. 4, the
the D and G peaks (ID/IG) increases from 0.896 to 0.961 for the GO (Fig. 4A) displays a typical wrinkled structure. After
β-CD/RGO, indicating the restoration of sp2 domains on hydrazine reduction, the RGO (Fig. 4B) shows a clearly
reduction with hydrazine.40
restacking effect due to the removal of surface negatively
charged oxygen containing functional groups. However, the β-
CD/RGO (Fig 4C) shows a flatter surface with very low level
of agglomeration in comparison to RGO, indicating the surface
functionalization could actually prevent the restacking effect of
RGO and remain the specific surface area of the material. The
morphology of GO and β-CD/RGO was also characterized by
TEM. According to the images shown in Fig. S1, the surface of
GO is smooth like silk fabric (Fig. S1A). The surface contrast
apparently increases after the modification of β-CD (Fig. S1B).
The increase of surface roughness is an indication that β-CD
have been coated on the surface of RGO which is consistent
with the literature.48
Fig. 2 A: UV-vis spectra and B: Raman spectra of GO and β-
CD/RGO dispersions.
FTIR analysis is used to analyse the surface
functionalization process of graphene sheets. The FTIR spectra
of GO, β-CD, PDDA and β-CD/RGO are depicted in Fig. 3.
The spectrum of GO displays peaks at 1710, 1592, 1398 and
1024 cm−1, which belong to the C═O stretching of COOH
groups, C=C vibrations, C━OH stretching vibrations and C━
O vibrations from alkoxy groups, respectively.41-43 After
hydrazine reduction, the intensity of these characteristic peaks
significantly decreased or even vanished, indicating the GO
sheets have been reduced successfully. Compared with the β-
CD spectrum, the spectrum of β-CD/RGO exhibits typical β-
CD absorption peaks of CHn stretching vibrations at 2925 cm−1
,
O
━ ━
H bending vibrations at 1140 cm−1 and the coupled C
O/C
━
C stretching at 1026 cm−1, which confirm the successful
functionalization of β-CD to the RGO sheets. 44-46 In addition,
compared with the spectrum of PDDA, β-CD/RGO spectrum
shows the absorption peaks at 2925, 1480 and 882 cm−1
correspond to CHn, CH2 and C
━
N vibrations of the nitroso
47
groups of PDDA, respectively.44,
These absorption peaks
confirmed the presence of PDDA. In summary, the spectrum of
β-CD/RGO shows both features of β-CD and PDDA, indicating
the RGO sheets were successfully functionalized with β-CD
and PPDA.
Fig. 4 SEM images of (A) GO, (B) RGO and (C) β-CD/RGO.
3.2 Electrochemical activities of paracetamol at various
electrodes
The electrochemical responses of paracetamol at various
electrodes were investigated using cyclic voltammetry. As
shown in Fig. 5A, paracetamol only shows an irreversible
oxidation peak at a bare GCE (curve a). In contract, RGO
modified GCE exhibits a pair of well-defined redox peak
corresponding to the oxidation (0.40 V) and reduction (0.35 V)
of paracetamol (curve b). This enhancement is probably due to
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 3

View Article Online
DOI: 10.1039/C5RA12520K
Page 5 of 7
ARTICLE
RSC Advances
Journal Name
the large surface area and outstanding conductivity which is Fig. 6A shows the effect of pH on the redox behavior of
provided by the RGO sheets. Moreover, when the as-prepared paracetamol using cyclic voltammetry at β-CD/RGO modified
β-CD/RGO nanohybrid was modified onto the GCE surface, GCE. It can be clearly observed that both oxidation and
the current responses of this pair of well-defined redox peaks reduction potentials shift to negative region with increasing pH,
from paracetamol increased greatly although the background suggesting that the electrochemical reaction of paracetamol
current of the β-CD/RGO modified GCE also increase in some involves transfer of protons.14, 20 Moreover, as shown in the
degree (curves c and d). The reasons that β-CD could further inset of Fig. 6A (black line), the oxidation potentials have a
increase the current response of paracetamol are mainly due to linear relationship with pH change. The regression equation can
two aspects. Firstly, the adsorption of paracetamol on pure be expressed as Epa (V) = 0.684 ─0.051 pH (R = 0.989). The
RGO is a single-layer adsorption, while on the β-CD/RGO slope value of 0.051 V/pH is very close to the theoretical value
nanohybrid it is a combined process of surface envelope of 0.059 V/pH based on the Nernst equation,14, 17 indicating that
behavior between cyclodextrin and paracetamol together with a the same proportion of protons and electrons involved in the
single layer adsorption. Thus β-CD/RGO allows adsorbing redox process. Thus according to the calculated numbers of
more drug molecules on the electrode surface resulting in electrons (section 3.2), the redox mechanism of paracetamol
higher sensitivity. Secondary, the introducing β-CD onto the involves 2 protons and 2 electrons (Fig. 6B). In addition, the
surface of RGO can enhance the sensitivity of detection for inserted Fig 6A (blue line) shows the relationship between the
drug molecules through the formation of supramolecular oxidation peak currents and pH values. The peak currents
complexes between β-CD and paracetamol molecules.49 increase from 5 to 7 and then decrease from 7 to 10. Therefore,
Therefore, the synergistic effect of β -CD and RGO provides a pH 7 was chosen for the measurement of paracetamol, which is
superior interface for performing the sensitive electrochemical well fit to the real physiological conditions.
measurement of paracetamol.
The effect of scan rate on the redox current of paracetamol
using β-CD/RGO modified GCE was investigated in Fig. 5B. It
can be seen that both anodic and cathodic peak currents
increase along with increasing scan rate accompanied with
enlarged peak separation. Furthermore, both the anodic and
cathodic peak current showed linear relationship with the scan
rate from 20 to 200 mV/s (inset of Fig. 5B), suggesting that the
reaction of paracetamol at β-CD/RGO modified GCE is an
adsorption controlled process.19, 20 The regression equations are
Fig. 6 (A): Cyclic voltammograms of 0.1 mM paracetamol at β-
Epa = 0.32105+0.06482 log v (R = 0.996) and Epc = 0.43301–
0.05114 log v (R = 0.990), respectively. According to Laviron’s
model,50, 51 the number of electrons involved in the reaction and
the charge-transfer coefficient constant can be calculated as
1.963 and 0.441, respectively. The results indicate that two
electrons are involved in the electrochemical redox process of
paracetamol.
CD/RGO modified GCE in 0.2 M PBS at different pH values.
pH: 5.0, 6.0, 7.0, 8.0, 9.0, 10.0. Scan rate: 50 mV/s. Inset: the
relationship between pH and Epa (black line) and the effect of
pH on the oxidation peak currents (blue line). (B): Proposed
redox reaction mechanism of paracetamol.
The effect of the amount of β-CD/RGO modified on the
electrode surface on the current responses of paracetamol was
investigated. As shown in Fig. 7A, the oxidation peak current
increases remarkably when the amount of β-CD/RGO increases
from 2 μL to 4 μL and reach to the maximum at 5 μL. After that,
the peak current decreases, especially when the amount of β-
CD/RGO exceeded 6 μL. Consequently, 5 μL of β-CD/RGO
dispersion was utilized to modify the GCE.
The pre-adsorption time is an important factor during the
electrochemical determination of paracetamol. The relationship
between oxidation peak currents and the pre-adsorption time
was investigated from 0 to 12 min and depicted in Fig. 7B. The
response current increases clearly from 0 to 4 min and remains
similar responses after 4 min. Thus, 4 min pre-adsorption time
was used throughout the measurements.
Fig. 5 A) Cyclic voltammograms of (a) bare, (b) RGO and (d)
β-CD/RGO modified GCE in 0.2 M pH 7.0 PBS with 0.1 mM
paracetamol and (c) β-CD/RGO without paracetamol. Scan
rate: 50 mV/s. B) Cyclic voltammograms of β-CD/RGO
modified GCE in 0.1 mM paracetamol at scan rates from 20 to
200 mV/s. The inset is the corresponding plots of current
responses vs scan rate.
3.3 Optimization of the detection conditions
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012

View Article Online
DOI: 10.1039/C5RA12520K
RSC Advances
Page 6 of 7
Journal Name
ARTICLE
Fig. 8 (A) Typical current-time response of β-CD/RGO
modified GCE upon the successive addition of: 0.01 and 0.1
mM paracetamol. (B) Amperometric response of β-CD/RGO
modified GCE upon the addition of 0.1 mM of paracetamol,
uric acid, dopamine, ascorbic acid and glucose in PBS. Applied
voltage: +0.4 V
Conclusions
In this work, we have demonstrated a novel paracetamol
electrochemical sensor based on β-CD/RGO modified electrode.
β-CD functionalized RGO was synthesized via a simple wet
chemical method. The electrochemical behavior of paracetamol
was greatly enhanced by the senor due to the combination of
the advantages of both β-CD and RGO materials. Specifically,
the fabricated electrode showed a liner detection range from
0.01 to 0.1 mM with a low detection limit of 2.3 μM. Moreover,
the proposed paracetamol sensor exhibited an excellent anti-
interference behavior.
Fig. 7 The plot of current response vs (A) the amount of β-
CD/RGO and (B) pre-adsorption time at β-CD/RGO modified
GCE towards 0.1 mM paracetamol.
3.4 Amperometric determination of paracetamol
The amperometric response of β-CD/RGO modified GCE upon
the successive addition of paracetamol in pH 7.0 PBS was
shown in Fig. 8A. As can be seen, the β-CD/RGO modified
GCE responds quickly on the concentration change of Acknowledgements
Swinburne University Postgraduate Research Award (SUPRA)
paracetamol. The steady-state current was achieved within 7 s
after the addition of paracetamol. The inset of Fig 8A
represents the calibration curve between the current response
and the concentration of paracetamol from 0.01 to 0.1 mM. The
corresponding linear equation is I (μA) = 0.0278 Cparacetamol (μM)
+ 0.695 with a correlation coefficient of 0.998. The detection
limit was calculated to be 2.3 μM at the signal to noise ratio of
and the National Natural Science Foundation of China
(21475033) are acknowledged for partially supporting this
work.
Notes and references
a Faculty of Science, Engineering and Technology, Swinburne University
of Technology, Hawthorn VIC 3122, Australia
b Department of Chemistry, Hubei Normal University, Huangshi 435002,
PR China
3
(S/N=3). The analytical performances of β-CD/RGO
modified GCE were compared with other nitrite sensors in the
literature and the results are shown in Table S1.
* Corresponding author. E-mail: aiminyu@swin.edu.au.
The influence of potential interferences on the
electrochemical measurement of paracetamol was studied. Fig
8B shows the amperometric response of β-CD/RGO modified
GCE upon addition of paracetamol and various interfering
species including uric acid, dopamine, ascorbic acid and
glucose. As shown in Fig 8B, the addition of 0.01 mM
paracetamol results in a quick current response while the
addition of 0.8 mM uric acid, dopamine, ascorbic acid and
glucose does not affect the current response. The results reveal
that the β-CD/RGO modified GCE has excellent selectivity
even the sample contains 10-fold concentration of interference
species.
The reproducibility of the β-CD/RGO modified GCE was
investigated by 7 successive scans in the PBS containing 0.1
mM paracetamol. A relative standard deviation of 2.9% was
obtained, indicating the β-CD/RGO modified GCE owing a
good reproducibility.
1.
2.
R. Goyal, V. Gupta, M. Oyama and N. Bachheti, Electrochemistry
Communications, 2005, 7, 803-807.
P. Chandra, N. X. Son, H.-B. Noh, R. N. Goyal and Y.-B. Shim,
Biosensors and Bioelectronics, 2013, 39, 139-144.
K. J. Heard, N. Engl. J. Med., 2008, 359, 285-292.
K. V. Blake, D. Bailey, G. M. Zientek and L. Hendeles, Clinical
Pharmacy, 1988, 7, 391-397.
H. Z. Toklu, A. Ö. Şehirli, A. Velioğlu-Öğünç, Ş. Çetinel and G.
Şener, European Journal of Pharmacology, 2006, 543, 133-140.
Sirajuddin, A. R. Khaskheli, A. Shah, M. I. Bhanger, A. Niaz and
S. Mahesar, Spectrochimica Acta. Part A, Molecular and
Biomolecular Spectroscopy, 2007, 68, 747-751.
J. Vilchez, R. Blanc, R. Avidad and A. Navalón, Journal of
Pharmaceutical and Biomedical Analysis, 1995, 13, 1119-1125.
A. W. Abu-Qare and M. B. Abou-Donia, Journal of
Pharmaceutical and Biomedical Analysis, 2001, 26, 939-947.
K. G. Kumar and R. Letha, Journal of Pharmaceutical and
Biomedical Analysis, 1997, 15, 1725-1728.
3.
4.
5.
6.
7.
8.
9.
10.
11.
D. Easwaramoorthy, Y.-C. Yu and H.-J. Huang, Analytica
Chimica Acta, 2001, 439, 95-100.
A. Trettin, A. A. Zoerner, A. Böhmer, F.-M. Gutzki, D. O.
Stichtenoth, J. Jordan and D. Tsikas, Journal of Chromatography
B, 2011, 879, 2274-2280.
12.
13.
14.
15.
A. Kunkel, S. Günter and H. Wätzig, Electrophoresis, 1997, 18,
1882-1889.
Y. Li, S. Feng, S. Li, Y. Zhang and Y. Zhong, Sensors and
Actuators B: Chemical, 2014, 190, 999-1005.
A. Kutluay and M. Aslanoglu, Sensors and Actuators B:
Chemical, 2013, 185, 398-404.
N. G. Tsierkezos, S. H. Othman and U. Ritter, Ionics, 2013, 19,
1897-1905.
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 5

View Article Online
DOI: 10.1039/C5RA12520K
Page 7 of 7
ARTICLE
RSC Advances
Journal Name
16.
M. Zheng, F. Gao, Q. Wang, X. Cai, S. Jiang, L. Huang and F. 49.
Gao, Materials Science Engineering. C, Materials for
Biological Applications, 2013, 33, 1514-1520.
W. Si, W. Lei, Z. Han, Y. Zhang, Q. Hao and M. Xia, Sensors and 50.
M. El-Kemary, S. Sobhy, S. El-Daly and A. Abdel-Shafi,
Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy, 2011, 79, 1904-1908.
E. Laviron, J. Electroanal. Chem., 1974, 52, 355-393.
E. Laviron, J. Electroanal. Chem., 1979, 101, 19-28.
&
17.
18.
19.
20.
21.
Actuators B: Chemical, 2014, 193, 823-829.
51.
C.-W. Kung, C.-Y. Lin, R. Vittal and K.-C. Ho, Sensors and
Actuators B: Chemical, 2013, 182, 429-438.
M. Devaraj, R. K. Deivasigamani and S. Jayadevan, Analytical
Methods, 2013, 5, 3503.
J. Li, J. Liu, G. Tan, J. Jiang, S. Peng, M. Deng, D. Qian, Y. Feng
and Y. Liu, Biosensors & Bioelectronics, 2014, 54, 468-475.
K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang,
S. V. Dubonos, I. V. Grigorieva and A. A. Firsov, Science, 2004,
306, 666-669.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
A. K. Geim and K. S. Novoselov, Nature Materials, 2007, 6, 183-
191.
J. Li, C.-y. Liu and Y. Liu, Journal of Materials Chemistry, 2012,
22, 8426.
G. Yang, C. Lee, J. Kim, F. Ren and S. J. Pearton, Phys. Chem.
Chem. Phys., 2013, 15, 1798-1801.
H. Zhang, A. Xie, Y. Shen, L. Qiu and X. Tian, Phys. Chem.
Chem. Phys., 2012, 14, 12757-12763.
X. Li, G. Wang, X. Ding, Y. Chen, Y. Gou and Y. Lu, Phys.
Chem. Chem. Phys., 2013, 15, 12800-12804.
P. T. Yin, T.-H. Kim, J.-W. Choi and K.-B. Lee, Phys. Chem.
Chem. Phys., 2013, 15, 12785-12799.
K. Liu, J. Zhang, G. Yang, C. Wang and J.-J. Zhu,
Electrochemistry Communications, 2010, 12, 402-405.
J. Li, H. Feng, J. Li, Y. Feng, Y. Zhang, J. Jiang and D. Qian,
Electrochimica Acta, 2015, 167, 226-236.
Y. Guo, S. Guo, J. Ren, Y. Zhai, S. Dong and E. Wang, ACS
Nano, 2010, 4, 4001-4010.
Y. Liu, S.-Z. Kang and H.-Y. Zhang, Microchemical Journal,
2001, 70, 115-121.
J. Li, H. Feng, Y. Feng, J. Liu, Y. Liu, J. Jiang and D. Qian,
Microchim Acta, 2014, 181, 1369-1377.
S. Wu, X. Lan, L. Cui, L. Zhang, S. Tao, H. Wang, M. Han, Z.
Liu and C. Meng, Analytica Chimica Acta, 2011, 699, 170-176.
Y. Guo, Y. Chen, Q. Zhao, S. Shuang and C. Dong,
Electroanalysis, 2011, 23, 2400-2407.
W. Liu, C. Li, Y. Gu, L. Tang, Z. Zhang and M. Yang,
Electroanalysis, 2013, 2367-2376.
L. Tan, K.-G. Zhou, Y.-H. Zhang, H.-X. Wang, X.-D. Wang, Y.-
F. Guo and H.-L. Zhang, Electrochemistry Communications,
2010, 12, 557-560.
37.
38.
M. Chen, Y. Meng, W. Zhang, J. Zhou, J. Xie and G. Diao,
Electrochimica Acta, 2013, 108, 1-9.
H. N. Tien, V. H. Luan, L. T. Hoa, N. T. Khoa, S. H. Hahn, J. S.
Chung, E. W. Shin and S. H. Hur, Chemical Engineering Journal,
2013, 229, 126-133.
39.
40.
41.
42.
F. Tuinstra and J. L. Koenig, The Journal of Chemical Physics,
1970, 53, 1126-1130.
W. Feng, C. Liu, S. Lu, C. Zhang, X. Zhu, Y. Liang and J. Nan,
Microchim Acta, 2014. 181, 501-509.
J. Zhang, H. Yang, G. Shen, P. Cheng, J. Zhang and S. Guo,
Chemical Communications, 2010, 46, 1112-1114.
M. Ahmad, E. Ahmed, Z. L. Hong, J. F. Xu, N. R. Khalid, A.
Elhissi and W. Ahmed, Applied Surface Science, 2013, 274, 273-
281.
43.
44.
45.
46.
47.
48.
X. Li, Q. Wang, Y. Zhao, W. Wu, J. Chen and H. Meng, Journal
of Colloid and Interface Science, 2013, 411, 69-75.
X. Ye, Y. Du, D. Lu and C. Wang, Analytica chimica acta, 2013,
779, 22-34.
W. Zhang, M. Chen, X. Gong and G. Diao, Carbon, 2013, 61,
154-163.
H. Liu, C. Liu, X. Yang, S. Zeng, Y. Xiong and W. Xu, Analytica
Chimica Acta, 2008, 628, 87-94.
D. Manoj, D. Ranjith Kumar and J. Santhanalakshmi, Applied
Nanoscience, 2012, 2, 223-230.
L. Saghatforoush, M. Hasanzadeh and N. Shadjou, Journal of
Electroanalytical Chemistry, 2014, 714, 79-84.
6 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012