Supporting Information
Anodic Electrogenerated Chemiluminescence of
Ru(bpy)32+ with Quantum Dots as Coreactant and Its
Application to Quantitative Detection of DNA
Yong-Ping Donga,b, Ting-Ting Gaoa,b, Ying Zhoua,b, Li-Ping Jiang a,*, Jun-Jie Zhua,*
S-1
0.6
120
0.4
80
0.2
40
0.0
0
300
400
500
FL intensity/a.u.
Absorption
Figure S1. High resolution transmission electron microscopy image of CdSe QDs.
600
Wavelength/nm
Figure S2. UV-vis absorption and fluorescence spectra of CdSe QDs.
S-2
4000
ECL intensity/a.u.
Z"/ohm
1200
800
400
e
b
0
c
f
B
3000
2000
1000
d
0
a
0
500
1000
1500
2000
2500
0
5
10
15
20
25
Volume of modified QDs/μL
Z'/ohm
Figure S3. (A) EIS of GCE modified with different amounts of CdSe QDs from 0.01
Hz to 105 Hz for [Fe(CN)6]3-/4- (10 mM, 1:1) in 0.1 mol L-1 pH 7.4 PBS containing
0.10 mol L-1 KCl. (a) bare GCE, (b) 5μL QDs, (c) 10μL QDs, (d) 15μL QDs, (e) 20μL
QDs, (f) 25μL QDs. (B) Effects of the amount of the modified CdSe QDs on ECL
signals.
6000
3000
5000
ECL intensity/a.u.
ECL intensity/a.u.
4000
4000
3000
2000
1000
2000
0
-5.0
-4.5
-4.0
-3.5
-1
log CRu/mol L
1000
bare GCE in QDs/Ru(bpy)3
QDs/GCE in Ru(bpy)3
QDs/GE in Ru(bpy)3
2+
2+
2+
0
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Potential/V vs SCE
Figure S4. ECL curves of bare GCE in QDs/Ru(bpy)32+ mixing solution, QDs/GCE
and QD/gold electrode (GE) in Ru(bpy)32+ solution. The inset is the relationship
between ECL intensities at the QDs/GCE and Ru(bpy)32+ concentration.
S-3
Absorption
0.6
B
0.4
DNA
2+
Ru(bpy)3
0.2
Ru(bpy)3 +DNA
2+
0.0
FL intensity/a.u.
250
500
500
750
A
2+
Ru(bpy)3
250
2+
Ru(bpy)3 +DNA
0
500
600
700
800
Wavelength/nm
Figure S5. FL spectra (A) and UV-vis absorption spectra (B) of Ru(bpy)32+ and
Ru(bpy)32++DNA
10
8
Ru(bpy)3
2+
6
Zeta potential/mV
4
2+
Ru(bpy)3 /probe
2
0
-2
-4
-6
QDs
probe
-8
-10
Figure S6. Zeta potential of Ru(bpy)32+, probe DNA, Ru(bpy)32+ intercalated probe
DNA and QDs.
S-4
Table S1. Comparison of different ECL biosensors for the detection of DNA.
ECL system
Linear range
LOD
Ref.
0.1 pM-1.0 nM
0.091 pM
1
5 fM -1.0 pM
1.7 fM
2
50 aM-5 fM
50 aM
3
CdTe@SiO2/ S2O8
0.1 nM-2 μM
0.03 nM
4
Ru(bpy)32+ doped Si NPs/TPA
0.1 pM-2 nM
0.05 pM
5
Ru(bpy)32+/CdSe QDs
0.5 fM-5.0 pM
0.19 fM
This work
2+
Ru(bpy)3 /TPA
Luminol/Pt NPs-CdS NCs/H2O2
2-
CdS:Mn NCs/S2O8
2-
1. X. F. Tang, D. Zhao, J. C. He, F. W. Li, J. X. Peng, M. N. Zhang, Anal. Chem. 2013,
85, 1711-1718.
2. H. R. Zhang, J. J. Xu, H. Y. Chen, Anal. Chem. 2013, 85, 5321-5325.
3. Y. Shan, J. J. Xu, H. Y. Chen, Chem. Commun. 2009, 905-907.
4. W. Wei, J. Zhou, H. N. Li, L. H. Yin, Y. P. Pu, S. Q. Liu, Analyst, 2013, 138,
3253-3258.
5. Q. X. Sun, G. Z. Zou, X. L. Zhang, Electroanalysis, 2011, 11. 2693-2698.
Table S2 Determination of target DNA added in human serum samples with the
present ECL biosensor.
Serum samples
Added target
DNA/pM
Found target
DNA/pM
Recovery/%
RSD/%, n= 3
1
0.95
95
3.3
5
5.08
100.2
3.1
1
1.02
102
4.5
5
4.98
99.6
2.8
Sample 1
Sample 2
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