Electronic Supplementary Information A promising … · 2013. 12. 5. · 2 Fig. S1 FTIR spectra of (a) P(MMA-co-AMPS) and (b) Ag/P(MMA-co-AMPS). * Represents changes in the peak positions

1

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

mailto:[email protected]

mailto:[email protected]

2

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


3

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


4

(a) (b)

Fig. S3 SEM images of powder (a) P(MMA-co-AMPS) and (b) Ag-P(MMA-co-AMPS)

materials.


5

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

%


6

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.


7

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


8

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


9

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


10

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 /


11

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 Information A promising … · 2013. 12. 5. · 2 Fig. S1 FTIR spectra of (a) P(MMA-co-AMPS) and (b) Ag/P(MMA-co-AMPS). * Represents changes in the peak positions

Documents