Electronic Supplementary Information A promising … · 2013. 12. 5. · 2 Fig. S1 FTIR spectra of...
Transcript of Electronic Supplementary Information A promising … · 2013. 12. 5. · 2 Fig. S1 FTIR spectra of...
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Electronic Supplementary Information
A promising electrochemical sensing platform based on a silver nanoparticles
decorated copolymer for sensitive nitrite determination
Pankaj Kumar Rastogi, Vellaichamy Ganesan* and S. Krishnamoorthi
Department of Chemistry, Faculty of Science, Banaras Hindu University
Varanasi-221 005, UP, India
Telephone: + 91-542-2307321; Fax: + 91-542-2368127
E-mail: VG: [email protected] and [email protected]
*Corresponding author
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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Fig. S1 FTIR spectra of (a) P(MMA-co-AMPS) and (b) Ag/P(MMA-co-AMPS).
* Represents changes in the peak positions
3500 3000 1500 1000
80
90
100
**
*
1390
1197
1734
1472
627
750
1042
b
a
1147
1193
124414
5013
8415
51
1644
1730
2850
2952
2996
3437% T
rans
mitt
ance
Wavenumber / cm-1
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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Fig. S2 UV-visible spectra for (a) P(MMA-co-AMPS) and (b) Ag-P(MMA-co-AMPS)
coated on glass plate.
400 500 600 700
0.5
0.6
0.7
b
a
Ab
so
rban
ce (
a.u
.)
Wavelength / nm
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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(a) (b)
Fig. S3 SEM images of powder (a) P(MMA-co-AMPS) and (b) Ag-P(MMA-co-AMPS)
materials.
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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Fig. S4 TGA curves of (a) P(MMA-co-AMPS) and (b) Ag-P(MMA-co-AMPS) materials.
200 400 600
0
50
100
b
a
Temperature / 0C
Weig
ht
%
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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Fig. S5 Bode-phase angle and Bode amplitude plots for (A) GC/P(MMA-co-AMPS) and (B) GC/Ag-P(MMA-co-AMPS)
electrodes in 10.0 mM Fe(CN)63-
/Fe(CN)64-
(1:1 molar ratio) containing 0.1 M KCl solution.
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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Fig. S6 CVs of different concentrations of NO2− at the GC/Ag-P(MMA-co-AMPS) in 0.1
M PBS (pH 7.0) at scan rate 20 mVs-1
. Insert shows enlarged view of oxidation
peaks.
-0.4 0.0 0.4 0.8 1.2
-20
0
20
0.16 0.20 0.24
10
20
30
Cur
rent
/
Potential / V
Cu
rren
t /
Potential / V
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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Fig. S7 CVs recorded at GC/Ag-P(MMA-co-AMPS) electrode in the presence of 1.0 mM
NO2− at various scan rates (20, 50, 75, 100, 150, 200, 250, 300 and 400 mVs
-1).
Inset (i) shows plot of anodic peak currents vs. the square root of scan rate (v1/2
)
and inset (ii) shows plot of Ipa/ν1/2
vs. ν. Supporting electrolyte: 0.1 M PBS (pH
7.0).
-0.5 0.0 0.5 1.0
-100
0
100
0.3 0.6
40
80
(i)
Cu
rren
t /
/ (Vs-1)
1/2
0.2 0.4
150
200
(ii)
(Ip
a /
)
/
V -
1/2s
1/2
/ Vs-1
Cu
rren
t /
Potential / V
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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Fig. S8 Plots of (A) log(catalytic current) vs. log[NO2−] and (B) Epa vs. log ν for GC/Ag-
P(MMA-co-AMPS) electrode
2.4 2.8
1.0
1.5
log[NaNO2] / log[M]
log
(Ip
a)
/ lo
g(
)
A
-1.5 -1.0 -0.5
0.8
0.9
B
log() / log(Vs-1)
Ep
a / V
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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Fig. S9 (A). Chronoamperograms of different concentrations of NO2− in 0.1 M PBS (pH 7.0) at GC/Ag-P(MMA-co-AMPS).
(B). Plot of Icat/Il vs. t1/2
and (C). Plot of I vs. t−1/2
(inset shows slope of resulting straight lines vs. concentration of
NO2− plot).
0.20 0.24 0.28
2
4
6
8B d
c
b
a
I cat /
IL r
ati
ot
1/2 / s
1/2
0 4 80
200
400 A
Cu
rren
t /
t / s
0.4 0.60
50
100
0 1 2 30
50
100
C / mM
Slo
pe /
s1/2 C
t-1/2
/ s-1/2
Cu
rren
t /
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013
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Table S1 Impedance parameters at GC/P(MMA-co-AMPS) and GC/Ag-P(MMA-co-
AMPS) electrodes
Parameter GC/P(MMA-co-AMPS) GC/Ag-P(MMA-co-AMPS)
Rs (Ω) 130 127
CPE 1.14×10-6
1.92×10-6
Rct (Ω) 824 454
|Z| at lower frequency (Ω) 954 581
Phase angle (degree) 43 33
ket (cms-1
) 2.30×10-4
4.19×10-4
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry AThis journal is © The Royal Society of Chemistry 2013