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:
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 p-p*, polaron band to p* band, and p band to localized polaron band transitions of PANI, respectively [2]. However, the peak attributed to ZnS QDs is not prominent in the fabricated composite.
Fig. S1 UV-vis absorption spectra of ZnS QDs and ZnSQD@PANI nanocomposite
Photoluminescence analysis
Photoluminescence spectra of the composite films at room temperature (300K) 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].
Fig. S2 Fluorescence emission spectra of ZnS QDs and ZnSQD@PANI nanocomposite.
X-ray photoelectron spectroscopy survey scan of ZnSQD@PANI nanocomposite
Fig. S3 X-ray photoelectron spectroscopy of ZnSQD@PANI composite.
Surface morphology of PANI
Fig. S4 Scanning electron micrographs of PANI.
Cyclic voltammetry diagrams of developed biosensors
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) / △Rct (kΩ) / 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
Real samples
Table S2 Determination of clenbuterol hydrochloride concentrations spiked in pig urine using the fabricated biosensor.
Samples / Supplemented amount (nmol) / Detected amount (nmol) / Recovery (%) / RSD (n=3)(%)
1 / 0.01 / 0.0097 / 97 / 0.27
2 / 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
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.
1