Electronic Supplementary Material
Copper nanoclusters-based fluorescent probe for hypochlorite
Qin Tang, Tingting Yang, Yuming Huang*
The Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of
Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing
400715, China
*Corresponding
author,
Tel:
+86-23-68254843;
Fax:
+86-23-68254843;
E-mail:
yuminghuang2000@yahoo.com
The method to determine the molar concentration of Cu-NCs
The concentration of the Cu-NCs was calculated based on the hypothesis that the added
CuAc2 was completely reduced. This hypothesis was reasonable because Cu2+ was not observed
in the resulting Cu-NCs, which was revealed by the XPS analysis (Fig. 1d). In our case, 6.0 mg
Cu(CH3COO)2·H2O was used to prepare the Cu-NCs, corresponding to 0.03 mmol copper.
Because the resulting Cu-NCs solution was adjusted to 30 mL with water, hence the molar
concentration of Cu-NCs is 1.0 mM. This result is consistent with that by flame atomic
absorption spectrometry (FAAS). We used FAAS to detect concentration of Cu-NCs. The
concentration of the resulting Cu-NCs suspension by FAAS is about 63.5 mg·L-1, corresponding
to 1.0 mM.
1
Table S1. Quantum yield comparison of the Cu-NCs obtained in this work with other Cu-NCs in
the previous works.
Copper nanoclusters
Quantum yield (%)
References
polyethyleneimine-templated Cu-NCs
2.1
1
glutathione stabilized Cu-NCs
0.45
2
ethylene glycol stabilized Cu-NCs
0.65
3
pentaerythritol tetrakis 3-mercaptopropionate
2.2
4
2-mercapto-5-n-propylpyrimidine protected Cu-NCs
3.5
5
glutathione protected Cu-NCs
3.5
6
bovine serum albumin stabilized Cu-NCs
4.1
7
tetrabutylammonium nitrate stabilized Cu-NCs
13
8
12.64
This work
functionalized poly(methacrylic acid) stabilized Cu-NCs
poly(vinyl pyrrolidone) stabilized Cu-NCs
Fig. S1. TEM image of the PVP-capped Cu-NCs, Scale bar=10 nm;
2
Transmittance (%)
PVP
CuNCs
4000
3500
3000
2500
2000
1500
1000
500
-1
Wavenumber (cm )
Fig. S2. FT-IR spectra of PVP and PVP-capped Cu-NCs
C 1s
Cu NCs+ClO
284.86(C-C)
-
N 1s
399.99
286.03(C-O)
287.28(C=O)
Cu NCs+ClO
284.86(C-C)
Intensity
Intensity
288.6(O-C=O)
-
399.91
Cu NCs
286.02(C-O)
287.46(C=O)
288.6(O-C=O)
283
284
285
286
287
288
289
Binding energy (eV)
(A)
290
291
Cu NCs
292
396
398
400
402
Binding energy (eV)
404
(B)
3
533.28
O 1s
532.51
531.58
Intensity
Cu NCs+ClO
-
533.21
532.48
531.58
530
Cu NCs
531
532
533
534
535
Binding energy (eV)
(C)
Fig. S3. The high-resolution C 1s (A), N 1s (B) and O 1s (C) XPS spectra of the Cu-NCs before
and after reaction with hypochlorite
250000
Total counts
200000
150000
100000
50000
0
-100
-50
0
50
100
Zeta potential (mV)
Fig. S4. Zeta potential of the Cu-NCs
4
Fluorescence Intensity (a.u.)
1.0
0.8
0.6
0.4
0.2
0.0
0
10
20
30
40
50
60
Time (day)
Fig. S5. Evolution of the fluorescence response of the Cu-NCs as a function of storage time
Fluorescence Intensity (a.u.)
1.0
0.8
0.6
0.4
0.2
0.0
0
10
20
30
40
50
60
Time (min)
Fig. S6. Photostability of the Cu-NCs. Irradiation source: 150 W Xe lamp
5
Fluorescence Intensity (a.u.)
1.2
0.9
0.6
0.3
0.0
0
0.001 0.005 0.01
0.05
0.1
0.2
0.5
NaCl concentration (M)
Fig. S7. Stability of the Cu-NCs in different concentrations of NaCl ranging from 0.001 to 0.5 M
0.4
(F 0-F)/F 0
0.3
0.2
0.1
0.0
2
3
4
5
pH
6
7
8
Fig. S8. Effect of pH on FL quenching efficiency. Conditions: hypochlorite, 30 μM; Cu-NCs,
3μM; reaction time, 10 min
6
0.4
(F 0-F)/F 0
0.3
0.2
0.1
0.0
0
2
4
6
8
Time (min)
10
12
14
Fig. S9. Effect of reaction time. Conditions: pH, 6.0; hypochlorite, 30 μM; Cu-NCs, 3 μM
0.35
(F 0-F)/F 0
0.30
0.25
0.20
0.15
0.10
0
2
4
6
8
Cu-NCs concentration (μM)
10
Fig. S10. Effect of Cu-NCs concentration on FL quenching efficiency. Conditions: pH, 6.0;
hypochlorite, 30 μM; reaction time, 10 min
7
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8