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The Operating Conditions for the Sensitivity of Detection of Hydrogen Peroxide for the Electrode
Modified with Copper Hexacyanoferrate
Chia-Cheng Hsiao(蕭佳政), Chung-Min Lien(連崇閔) , Hau Lin(林浩)
Department of Chemical and Materials Engineering, Southern Taiwan University
ABSTRACT
A study was conducted to use the Coprecipitation method to prepare the Copper(Ⅱ) Hexacyanoferrate(Cu(Ⅱ)HCF) [Cu(Ⅱ)HCF : graphite carbon powders = 3 : 7(weight ratio)]. The Cu(Ⅱ)HCF was used to modify
the carbon paste electrode because the Cu(Ⅱ)HCF possessed the excellent catalytic characteristic and it could be used with the graphite carbon powders and carbon paste to make the carbon paste electrode to elevate the
responding current of the hydrogen peroxide at different operating conditions. The TB (Time Base ) graphs for different operating potentials, stirring rates, and pH values were plotted to determine the optimum
operating conditions. At the optimum operating conditions - 0.2 V operating potential, 500rpm stirring rate and in 0.05M PBS buffer solution(pH=7.4), the detection limit was 0.02 mM H2O2, the linear range was
0.02~2.6 mM H2O2, R2=0.9945 and the sensitivity was 121.606 μA/cm2ּmM H2O2.
INTRODUCTIO
N
Working
Electrode
※Three Electrodes System：
Pt
Ag/AgCl
Hydrogen peroxide is widely used in the industry and food preservation, and therefore developing
a hydrogen peroxide sensor which can detect the hydrogen peroxide rapidly and conveniently is an
important research subject. In recent years, diabetes has become one of the top ten causes of death for
the people in our country. Therefore developing a rapid and convenient glucose biosensor also has
become an important research subject. Because the copper(Ⅱ) hexacyanoferrate possesses the excellent
catalytic characteristic it can be used with the carbon paste and graphite carbon powders which
possess the excellent conductivity to make the carbon paste electrode and to elevate the responding
current of the hydrogen peroxide. The carbon paste electrode is used to detect the responding current
of hydrogen peroxide in PBS buffer solution and the concentration of hydrogen peroxide can be
determined from the responding current of hydrogen peroxide. The glucose and oxygen can be
catalyzed by the glucose oxidase to produce gluconic acid and hydrogen peroxide, and the
concentration of the glucose can then be determined.
Counter
Electrode
Reference
Electrode
N2
pH 7.4之0.05 M PBS
Buffer Solution
Temperature at
30℃
RESULTS AND DISCUSSION
(A)
(B)
(C)
Fig 2. CV graphs for (A) carbon paste electrode
modified with Cu(Ⅱ)HCF ( stirring by
homogenizer ) (B) carbon paste electrode modified
with Cu(Ⅱ)HCF (stirring by magnetic stirrer) (C)
unmodified carbon paste electrode
Fig. 3 The TB graphs of carbon paste electrode
for detection of H2O2 at different operating
potentials (Cu(Ⅱ)HCF : graphite carbon
powders = 3 : 7); the operating potentials are
[ (A) 0V (B) –0.05V (C) –0.1V (D) –0.2V (E) –
0.3 V ]
Fig 1. The theory of detection of glucose for the biosensor
EXPERIMENTAL
Preparation of Copper(Ⅱ) Hexacyanoferrate(Cu(Ⅱ)HCF) ：
3(CuSO4．5H2O)+ 2〔K3[Fe(CN)6]〕
Cu3[Fe(CN)6]2 + 3K2SO4 + 15H2O
Coprecipitation method：
：
Stoichiometry 3
2
(mole ratio)
Separation of side product
Fig. 4 The TB graphs of carbon paste electrode
for detection of H2O2 at different stirring rates
(Cu(Ⅱ)HCF : graphite carbon powders = 3 : 7);
the stirring rates are [ (A) 200 rpm (B) 300 rpm
(C) 400 rpm (D) 500 rpm (E) 600 rpm ]
Drying at 60℃ (48 hours)
CuSO4 ． 5H2O(aq)
(MERCK）
K3Fe(CN)6(aq)（MERCK）
Cu3[Fe(CN)6]2 (aq)
Preparation of the working electrode :
Fig. 5 The TB graphs of carbon paste electrode
for detection of H2O2 at different pH values of
PBS buffer solution (Cu(Ⅱ)HCF : graphite
carbon powders = 3 : 7); the pH values are [ (A)
pH = 4.0 (B) pH = 5.0 (C) pH = 6.0 (D) pH =
7.4 (E) pH = 8.0 ]
copper(Ⅱ)
hexacyanoferrate
1.
Surface area of
electrode=0.0805cm2
7 cm
0.05
cm
0.5 cm
2. Then the Copper(Ⅱ) Hexacyanoferrate powders, graphite carbon powders and carbon paste were
mixed with the appropriate ratio (Copper(Ⅱ) Hexacyanoferrate : graphite carbon powders : carbon paste
= 0.3 : 0.7 : 1). After the mixing was complete, the mixture was evenly coated on the nake-ended electric
wire and dried in the oven and then we obtained the carbon paste electrode.
Fig. 6 The TB graphs of carbon paste electrode
for detection of H2O2 (pH=7.4)
Fig. 7 The TB graphs of carbon paste electrode
for detection of H2O2 , 10μL of 100mM H2O2 is
injected per 100 seconds (pH=7.4)
CONCLUSIONS
The mixing of
Cu(Ⅱ)HCF
and carbon
The results showed that the responding current for the carbon paste electrode
modified with the Copper(Ⅱ) Hexacyanoferrate was elevated significantly. The TB
(Time Base ) graphs for different operating potentials, stirring rates, and pH values
were plotted to determine the optimum operating conditions. At the optimum
operating conditions –0.2V operating potential, 500rpm stirring rate and in 0.05M
PBS buffer solution(pH=7.4), the detection limit was 0.02 mM H2O2, the linear range
was 0.02~2.6 mM H2O2, R2=0.9945 and the sensitivity was 121.606 μA/cm2ּmM H2O2.
This research can be further applied to the glucose biosensor in the future.
powders was
evenly
Mixing with
equal amount of
carbon paste
銅
芯
電
線
REFERENCES
1. W. Oungpipat, P. W. Alexander and P. Southwell-Keely, “ A Reagentless Amperometric Biosensor
for Hydrogen Peroxide Determination Based on Asparagus, Tissue and Ferrocene Mediation, ”
Analytica Chimica Acta, 309, 35 (1995).
2. Y. -M. Uang and T.-C. Chou, “Criteria for Designing a Polypyrrole Glucose Biosensor by
Galvanostatic Electropolymerization, ” Electroanalysis, 14, 1564 (2002).
3. M. A. Kim and W. -Y. Lee, “Amperometric Phenol Biosensor Based on Sol-Gel Silicate/Nafion
Composite Film,” Analytica Chimica Acta, 479, 143 (2003).