Electronic Supplementary Material
Electrochemical sensing of nitrite using a glassy carbon electrode modified with reduced
functionalized graphene oxide decorated with flower-like zinc oxide
Marlinda Ab Rahmana, Alagarsamy Pandikumar a*, Norazriena Yusoff a, Nay Ming Huang a*, Hong
Ngee Lim b,c*
a
Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University
of Malaya, 50603 Kuala Lumpur, Malaysia
b
Department of Chemistry, Faculty of Science, University Putra Malaysia, 43400 UPM Serdang,
Selangor, Malaysia
c
Functional Device Laboratory, Institute of Advanced Technology, University Putra Malaysia, 43400
UPM Serdang, Selangor, Malaysia
% Transmittance (a.u)
*Corresponding author(s) e-mail: huangnayming@um.edu.my and pandikumarinbox@gmail.com
FGO
925
710
1212
2937
2806
1098
rGO
1595
4000
3500
3000
2500
2000
1405
1500
Wavenumber (cm-1)
1000
500
Fig. S1 FT-IR spectra of FGO and rGO.
1
Fig. S2 TEM images of FGO (a), and (b) lower and (c) higher magnifications of f-ZnO@rFGO
nanocomposite.
1000
Current (A)
800
600
y = 0.3809x + 1.6125E-5
R2 = 0.9987
400
200
0
0.0
0.5
1.0
1.5
[NO2-](m)
2.0
2.5
3.0
Fig. S3 The linear correlation plot obtained for f-ZnO@rFGO modified electrode in presence of nitrite
at concentration range of 0.1–3 mM in 0.1 M pH 7.2 phosphate buffer at scan rate of 50 mV.s-1.
2
300
y = 0.0355x + 9.7364E-5
R2 = 0.9885
Current ()
250
200
150
100
y = 0.2145x + 1.1731E-5
R2 = 0.9636
50
0
0
1
2
3
[NO2-]/mM
4
5
Fig. S4 The linear correlation plot obtained for f-ZnO@rFGO modified electrode in presence of nitrite
at concentration range of 10 µM to 5 mM in 0.1 M pH 7.2 phosphate buffer at scan rate of 50 mV.s-1.
1 mM NO2-
12
Current (A)
10
8
6
4
2
0
0
500
1000
1500
2000
2500
Time (s)
Fig. S5 The amperometric i–t curve obtained for the 1 mM of nitrite with f-ZnO@rFGO modified
electrode in 0.1 M phosphate buffer (pH 7.2) at applied potential of 0.9 V.
3
Table S1: Analytical parameters reported for some modified electrodes towards nitrite detection
Modified electrode
Linear range
Detection limit
Reference
PEDOT/Graphene modified electrode
0.5-240 µM
0.15 µM
[1]
50 µM-2.5 mM
10 mM
[2]
NP-Fe2O3-CoO composite
0.2-16.2 mM
0.1 µM
[3]
GR/PPy/CS nanocomposite modified GCE
0.5-722 µM
0.1 µM
[4]
1-127 µM
0.07 µM
[5]
CR-GO modified GCE
8.9-167 µM
1.0 µM
[6]
PEDOT/GR modified GCE
0.3-600 µM
0.1 µM
[7]
CoNi/ErGO
0.1-330 µM
0.05 µM
[8]
CoOx/MWCNTs/GCE
0.5-250 µM
0.3 µM
[9]
Nano-Au/P3MT modified GCE
10-1000 µM
2.3 µM
[10]
GCE/f-ZnO@rFGO
10 µM-8 mM
33 µM
This Work
Graphene nanoplatelet-protein composite film
HAC modified GCE
Footnote: PEDOT = poly(3,4-ethylenedioxythiophene); SPCEs = screen-printed carbon electrodes;
MWCNTs = multi-wall carbon nanotubes; NP-Fe2O3-CoO = nanoporous Fe2O3–CoO composite ; GCE
= glassy carbon electrode; GR/PPy/CS = graphene/polypyrrole/chitosan; HAC = heteratom-enriched
activated carbon; CR-GO = chemically reduced graphene oxide; PEDOT/GR = poly(3,4ethylenedioxythiophene)/graphene nanocomposite; IL–SWCNT = ionic liquid single-walled carbon
nanotube; Hb/Au/GACS = hemoglobin graphene with biocompatible chitosan; nano-Au/P3MT = gold
nanoparticles on poly(3-methylthiophene).
4
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