Electronic Supplementary Material
Electrochemical clenbuterol immunosensor based on a gold electrode
modified with zinc sulfide quantum dots and polyaniline
Zhihong Zhang 1,2*, Fenghe Duan1, Linghao He 1, Donglai Peng 1, Fufeng Yan 1, Minghua
Wang 2, Wei Zong 3, Chunxiao Jia 1
1
State Laboratory of Surface and Interface Science of Henan Province，Zhengzhou University
of Light Industry, No. 166, Science Avenue, Zhengzhou 450001, P. R. China;
2
Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological
Restoration, Zhengzhou University of Light Industry, No. 166, Science Avenue, Zhengzhou
450001, P. R. China;
3
Henan Collaborative Innovation Center of Food Production and Safety, Zhengzhou
University of Light Industry, No. 166, Science Avenue, Zhengzhou 450001, P. R. China
*Corresponding author, Tel.: +0086-37186609676, Fax: +0086-37186609676,
∗
E-mail
address: mainzhh@163.com
Optical absorbance spectroscopy analysis
The UV–visible spectra of ZnS QDs and ZnSQD@PANI nanocomposite are shown in Fig. S1.
The absorption peak at 302 nm corresponds to ZnS QDs [1]. In ZnSQD@PANI, the
adsorption peaks at 361, 444, and 876 nm correspond to *, polaron band to * band, and
band to localized polaron band transitions of PANI, respectively [2]. However, the peak
attributed to ZnS QDs is not prominent in the fabricated composite.
1
429
Intensity /a.u.
10.0k
ZnS QDs
8.0k
6.0k
417
4.0k
ZnSQD@PANI
2.0k
0.0
350
400
450
500
550
600
650
Wavelength / nm
Fig. S1 UV-vis absorption spectra of ZnS QDs and ZnSQD@PANI nanocomposite
Photoluminescence analysis
Photoluminescence spectra of the composite films at room temperature (300 K) and excitation
wavelength of 320 nm are shown in Fig. S2. The emission peak at 429 nm is associated with
stoichiometric vacancies or defect-related emission of ZnS QDs [2]. The peak exhibits blue
shift to 417 nm, which is probably due to changes in particle size or phase of the ZnS
nanocrystals [3].
ZnSQD@PANI
Intensity
1.5
361
1.0
444
876
0.5
302
ZnS QDs
0.0
200
300
400
500
600
700
800
900
Wavelength/nm
Fig. S2 Fluorescence emission spectra of ZnS QDs and ZnSQD@PANI nanocomposite.
2
X-ray photoelectron spectroscopy survey scan of ZnSQD@PANI nanocomposite
Intensity /a.u.
Zn 2p
O 1s
C 1s
N 1s
1200
1000
800
600
400
S 2p
200
0
Binding Energy / eV
Fig. S3 X-ray photoelectron spectroscopy of ZnSQD@PANI composite.
Surface morphology of PANI
(a)
(b)
Fig. S4 Scanning electron micrographs of PANI.
3
Cyclic voltammetry diagrams of developed biosensors
(a)
150
gold electrode
ZnSQD@PANI
IgG
CHanti
CH
Current / A
100
50
(b)
gold electrode
PANI
IgG
CLBanti
100
Current / A
150
0
-50
-100
50
CLB
0
-50
-100
-150
-0.2
0.0
0.2
0.4
0.6
0.8
-150
-0.2
Potential / V
0.0
0.2
0.4
0.6
0.8
Potential / V
(c)
gold electrode
ZnS QDs
IgG
CLBanti
100
Current / A
50
CLB
0
-50
-100
-0.2
0.0
0.2
0.4
0.6
0.8
Potential / V
Fig. S5 Cyclic voltammetry curves of the developed biosensor based on (a) ZnSQD@PANI
nanocomposite, (b) PANI, and (c) ZnS QDs for detecting 1 ng·mL−1 CH.
Repeatability of the electrochemical biosensor
Table S1 Repeatability of the developed electrochemical biosensor.
Times
Rct(CH)
△
(0.5 ng·mL-1)
(kΩ)
Rct RSD (n=3)
(%)
1
4.19
2.09
0
2
4.08
1.95
0.1
3
4.00
2.04
0.23
4
4.95
1.90
0
5
4.05
1.982
0.146
4
Real samples
Table S2 Determination of clenbuterol hydrochloride concentrations spiked in pig urine using
the fabricated biosensor.
Supplemented
Detected
amount
amount
(nmol)
(nmol)
1
0.01
2
Recovery
RSD (n=3)
(%)
(%)
0.0097
97
0.27
0.1
0.0964
96.39
0.13
3
0.5
0.510
102
0.15
4
1
0.978
97.85
0.09
5
2
2.06
103
0.13
6
10
11.49
100.15
0.12
Samples
References
1 Labiadh H, Chaabane T B, Balan L, Becheik N, Corbel S, Medjahdi G and Schneider R
(2014) Preparation of Cu-doped ZnS QDs/TiO2 nanocomposites with high photocatalytic
activity. Applied Appl. Catalysis Catal. B: Environmental Environ. 144: 29-35.
2 Shit A, Chatterjee S and Nandi A K (2014) Dye-sensitized solar cell from polyaniline–ZnS
nanotubes and its characterization through impedance spectroscopy. Physical Phys.
Chemistry Chem. Chemical Chem. Physics Phys. 16: 20079-20088.
3 Dey S K and Sarkar D (2014) Effect of Zn source concentration on structural, optical and
electrical properties of zinc sulphide–-polyaniline (ZnS–-PANI) nanocomposite thin films.
Journal of. Materials Mater. ScienceScie.: Materials Mater.in Electronics Electron. 25:
5638-5645.
5