Electronic Supplementary Material

A glassy carbon electrode modified with a nanocomposite consisting of molybdenum disulfide intercalated into self-doped polyaniline for the detection of bisphenol A

Tao Yang1,[*], Huaiyin Chen1, Ruirui Yang1, Yuhang Jiang1, Weihua Li2,*, and Kui Jiao1

1 Key Laboratory of Sensor Analysis of Tumor Marker of Education Ministry, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China

2 Qingdao Technological University (Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone, Qingdao 266033, China

Raman spectrum characterization of MoS2 and MoS2-SPAN

Fig. S1 The Raman spectra of MoS2 and MoS2-SPAN

For MoS2 and MoS2-SPAN, the Raman spectra in Fig. S2 show strong signals from both the in-plane E12g and the out-of-plane A1g vibration of MoS2 at the peaks of 375 and 404 cm−1, respectively [1]. For MoS2-SPAN, the peaks observed at 434, 529, 794, 1168, 1224 cm−1 correspond to phenazine-like segments, out-of-plane C-H deformation of quinonoid rings, C-H bending in quinonoid rings, C-N stretching, C-H bending in benzenoid rings, respectively. And the peaks at 1409 and 1471 cm−1 belong to C=N and C=C stretching [2]. The S=O vibration of the sulfonate group is verified by the peak at 1072 cm−1, which indicates the formation of SPAN [3].

The electroactive surface areas of the modified electrodes

The electroactive surface areas of the electrodes were acquired by CVs using 1.0×10−3 M [Fe(CN)6]3−/4− as the indicator according to the Randles-Sevcǐk equation: ipa = 2.69×105AD1/2n3/2v1/2C. Where ipa is the anodic peak current, n refers to the electron transfer number, A represents the surface area of the electrode, D is the diffusion coefficient, C expresses the concentration of [Fe(CN)6]3−/4− and v is the scan rate. For 1.0×10−3 M [Fe(CN)6]3−/4− in 0.1 M KCl electrolyte, n = 1, D = 6.70×10−6 cm2 s−1, then from the slope of the ipa - ν1/2 relation, the electroactive surface area can be calculated (Table S1).

Table S1. The electroactive areas of different modified electrodes

Electrodes / ipa/μA / Electroactive surface areas/cm2
MoS2/GCE / −13.83 / 0.063 ± 0.0003
SPAN/GCE / −25.08 / 0.115 ± 0.0004
MoS2-SPAN(1:1)/GCE / −32.09 / 0.145 ± 0.0003
MoS2-SPAN(2:1)/GCE / −40.21 / 0.183 ± 0.0004
MoS2-SPAN(3:1)/GCE / −37.45 / 0.170 ± 0.0002
MoS2-SPAN(3h)/GCE / −26.24 / 0.119 ± 0.0001
MoS2-SPAN(4h)/GCE / −30.36 / 0.137 ± 0.0002
MoS2-SPAN(5h)/GCE / −40.21 / 0.183 ± 0.0004
MoS2-SPAN(6h)/GCE / −34.58 / 0.157 ± 0.0001


Optimization of pH value for BPA detection

Fig. S2 (A) DPVs of 1.0×10−4 M BPA recorded at MoS2-SPAN/GCE with different pH values of PBS (from a to e: 5.0, 6.0, 7.0, 8.0, 9.0); (B) Plots of the oxidation peak current of BPA versus different pH values.

Optimization of the accumulation time and potential

Comparison of different modified electrodes for BPA detection

Table S2. Comparison of our work with other modified electrodes for BPA detection

Electrodea / peak potential / pH value / Linear range/μM / Detection limit/nM / Reference
3Au-1Pd Alloy NPs/GN/GCE / 0.528 V (vs. Ag/AgCl) / 7.0 / 0.01–5.0 / 4 / [4]
C60/GCE / ≈0.42 V (vs. Ag/AgCl) / 8.0 / 0.074–0.23 / 3.7 / [5]
PBPIDS/GCE / 0.61 V (vs. SCE) / 8.0 / 0.01–10 / 8 / [6]
Mg-Al-SDS/GCE / 0.429 V (vs. SCE) / 9.0 / 0.008–2.8 / 2 / [7]
AuNPs/MoS2/GCE / 0.90 V (vs. SCE) / 7.0 / 0.05–100 / 5 / [8]
MoS2-SPAN/GCE / 0.446 V (vs. SCE) / 7.0 / 0.001–1.0 / 0.6 / This work

a The acronyms of the modified electrodes successively represent:

3Au-1Pd alloy nanoparticles/graphene composite modified GCE,

fullerene modified GCE,

poly{1-butyl-3-[3-(N-Pyrrolyl)propyl]imidazolium dodecyl sulfate ionic liquid} film modified GCE,

Mg-Al-sodium dodecyl sulfate modified GCE,

MoS2 and chitosan-gold nanoparticles composites modified GCE,

MoS2 and self-doped polyaniline nanocomposite modified GCE.

Analytical applications

With the purpose for evaluating the performance of MoS2-SPAN/GCE in practical analytical applications, the detection of BPA in three kinds of plastic samples (polycarbonate (PC) water bottle, PC infant nursing bottle, poly (vinyl chloride) (PVC) food package bag) was measured using the standard addition method. The sample solutions were prepared according to Deng’s paper [9]. The results were displayed in Table S3.

Table S3. Determination of BPA in real samples (n = 3)

Samplesa / Measuredb/μM / Added/μM / Foundb/μM / Recovery/%
PC water bottle / 0.264 ± 0.013 / 0.50 / 0.776 ± 0.033 / 102.4
PC infant nursing bottle / 0.307 ± 0.017 / 0.50 / 0.835 ± 0.046 / 105.6
PVC food package bag / 0.798 ± 0.038 / 0.50 / 1.273 ± 0.054 / 95.0

a Samples were get from the local supermarkets

b Average ± confidence interval, and the confidence level is 95 %

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[*]1 * ; Tel: +86-532-84022858; Fax: +86-532-84023927

2 * ; Tel: +86-532-82897531; Fax: +86-532-82897531