S-1 SUPPORTING INFORMATION for Molybdenum Disulfide Quantum ...
SUPPORTING INFORMATION for
Molybdenum Disulfide Quantum Dots as a Photoluminescence Sensing Platform for 2,4,6-Trinitrophenol Detection Yong Wanga and Yongnian Ni*ab a Department of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China b State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, China
* Corresponding author. Tel.: +86 791 83969500; fax: +86 791 83969500. E-mail address: [email protected]
S-1
The PL quantum yield (QY) of MoS2 QDs was determined by comparing the integrated emission intensity and absorbance with the reference quinine sulfate of known QY (0.546).1 The quinine sulfate was dissolved in 0.1 M H2SO4. Concentrations of quinine sulfate and MoS2 QDs were kept low so that the absorbances at the excitation wavelength were less than 0.1.2 The refractive index of the sample solution can be considered to be approximately equal to that of reference solution, and the value of the refractive index was 1.33. The QY for the MoS2 QDs sample can be calculated as2 QY = QYref
η η
2
2
ref
I Aref I ref A
(1)
where QYref is the quantum yield of the reference compound, η and ηref are the refractive index of the sample and reference solution, I and Iref are the integrated intensities (areas) of sample and standard spectra, and A and Aref represent the absorbance of sample and standard.
Table S1. Quantum yield of MoS2 QDs ___________________________________________________________________________________________ Sample
Integrated emission
Absorbance
Refractive index
Quantum Yield
intensity (I)
at 308 nm
of solvent (η)
(QY)
___________________________________________________________________________________________ Quinine sulfate
38907.6
0.013413
1.33
0.546 (known)a
MoS2 QDs
1846.8
0.013557
1.33
0.026
___________________________________________________________________________________________ a
See Ref. 1.
S-2
Table S2. Chemical structures of 2,4,6-trinitrophenol and four structurally related compounds ___________________________________________________________________________________________ Compound
Abbreviation
Molecular formula
Molecular weight
Structure
___________________________________________________________________________________________ 2,4,6-Trinitrophenol
TNP
C6H3N3O7
229.11
OH O2N
NO2
NO2
2,4,6-Trinitrotoluene
TNT
C7H5N3O6
CH3
227.13 O2N
NO2
NO2
p-Chlorophenol
PCP
C6H5ClO
128.56
OH
Cl
Phenol
PHE
C6H6O
94.11
OH
2,6-Di-tert-butyl-4-methylphenol
BHT
C15H24O
220.35
OH C(CH3)3
(CH3)3C
CH3
___________________________________________________________________________________________
S-3
TNT
PCP
PHE
BHT
Figure S1. PL spectra of MoS2 QDs solution under excitation at 308 nm with various concentrations of TNT (0, 2.0, 3.6, 6.9, 10.2, 13.5, 16.8, 20.1, 23.4, 26.7, 30.0, 33.2, 36.5, 43.1, 49.6, 56.1, 62.7, 69.2, 82.2, 95.2, 108.1, 121.0, 133.9, 146.7, 165.9, 197.7, 229.4, 260.8, 292.0, 323.0, 353.8, 384.4, 414.9, 445.1, 475.2, 505.0, 534.7, 564.2, 593.5, 622.6, 651.5, 680.3, 708.9 and 737.3 μM), PCP (0, 2.0, 3.6, 6.9, 10.2, 13.5, 16.8, 20.1, 23.4, 26.7, 30.0, 33.2, 36.5, 43.1, 49.6, 56.1, 62.7, 69.2, 82.2, 95.2, 108.1, 121.0, 133.9, 146.7, 165.9, 197.7, 229.4, 260.8, 292.0, 323.0, 475.2, 622.6, 765.5, 904.2, 1169.4, 1655.9, 2091.7, 2484.1, 2839.5, 3162.8, 3458.1 and 3729.0 μM), PHE (0, 2.0, 3.6, 6.9, 10.2, 13.5, 16.8, 20.1, 23.4, 26.7, 30.0, 33.2, 36.5, 43.1, 49.6, 56.1, 62.7, 69.2, 82.2, 95.2, 108.1, 121.0, 133.9, 146.7, 165.9, 197.7, 229.4, 260.8, 292.0, 323.0, 475.2, 622.6, 765.6, 904.2, 1169.4, 1656.0, 2091.6, 2484.1, 3162.8, 3458.1, 3729.0, and 3978.3 μM) or BHT (0, 2.0, 3.6, 6.9, 10.2, 13.5, 16.8, 20.1, 23.4, 26.7, 30.0, 33.2, 36.5, 43.1, 49.6, 56.1, 62.7, 69.2, 82.2, 95.2, 108.1, 121.0, 133.9, 146.7, 165.9 μM).
S-4
Figure S2. Plot of the quenching ratio (F0/F) for TNP, TNT, PCP, PHE and BHT at 402 nm versus their respective concentration.
TNT
PCP
PHE
Figure S3. Plot of Stern–Volmer constants for TNT, PCP or PHE quenching of MoS2 QDs as a function of emission wavelengths, and UV–Vis absorption spectra of the three structurally similar compounds in the 350–500 nm wavelength range. Other experiment conditions are as in Figure S1.
S-5
B
A
Figure S4. The hydrodynamic diameter of MoS2 QDs (A) and MoS2 QDs in the presence of TNP (B) measured by DLS method.
A
B
Figure S5. (A) PL spectra of MoS2 QDs under different conditions: (a) MoS2 QDs alone, (b) MoS2 QDs + 10 μM TNP, (c) MoS2 QDs + 10 μM TNP + 10 μM TNT, (d) MoS2 QDs + 10 μM TNP + 20 μM TNT. Other experiment conditions are as in Figure 4. (B) Selectivity of the MoS2 QDs–based PL sensor for TNP over TNT. The quenching ratio (F0/F) values are derived from PL spectral data in Figure S5A.
REFERENCES (1) Eaton, D. F. Pure Appl. Chem. 1988, 60, 1107–1114. (2) Brouwer, A. M. Pure Appl. Chem. 2011, 83, 2213–2228.
S-6
Molybdenum Disulfide Quantum Dots as a Photoluminescence Sensing Platform for 2,4,6-Trinitrophenol Detection Yong Wanga and Yongnian Ni*ab a Department of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, China b State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, China
* Corresponding author. Tel.: +86 791 83969500; fax: +86 791 83969500. E-mail address: [email protected]
S-1
The PL quantum yield (QY) of MoS2 QDs was determined by comparing the integrated emission intensity and absorbance with the reference quinine sulfate of known QY (0.546).1 The quinine sulfate was dissolved in 0.1 M H2SO4. Concentrations of quinine sulfate and MoS2 QDs were kept low so that the absorbances at the excitation wavelength were less than 0.1.2 The refractive index of the sample solution can be considered to be approximately equal to that of reference solution, and the value of the refractive index was 1.33. The QY for the MoS2 QDs sample can be calculated as2 QY = QYref
η η
2
2
ref
I Aref I ref A
(1)
where QYref is the quantum yield of the reference compound, η and ηref are the refractive index of the sample and reference solution, I and Iref are the integrated intensities (areas) of sample and standard spectra, and A and Aref represent the absorbance of sample and standard.
Table S1. Quantum yield of MoS2 QDs ___________________________________________________________________________________________ Sample
Integrated emission
Absorbance
Refractive index
Quantum Yield
intensity (I)
at 308 nm
of solvent (η)
(QY)
___________________________________________________________________________________________ Quinine sulfate
38907.6
0.013413
1.33
0.546 (known)a
MoS2 QDs
1846.8
0.013557
1.33
0.026
___________________________________________________________________________________________ a
See Ref. 1.
S-2
Table S2. Chemical structures of 2,4,6-trinitrophenol and four structurally related compounds ___________________________________________________________________________________________ Compound
Abbreviation
Molecular formula
Molecular weight
Structure
___________________________________________________________________________________________ 2,4,6-Trinitrophenol
TNP
C6H3N3O7
229.11
OH O2N
NO2
NO2
2,4,6-Trinitrotoluene
TNT
C7H5N3O6
CH3
227.13 O2N
NO2
NO2
p-Chlorophenol
PCP
C6H5ClO
128.56
OH
Cl
Phenol
PHE
C6H6O
94.11
OH
2,6-Di-tert-butyl-4-methylphenol
BHT
C15H24O
220.35
OH C(CH3)3
(CH3)3C
CH3
___________________________________________________________________________________________
S-3
TNT
PCP
PHE
BHT
Figure S1. PL spectra of MoS2 QDs solution under excitation at 308 nm with various concentrations of TNT (0, 2.0, 3.6, 6.9, 10.2, 13.5, 16.8, 20.1, 23.4, 26.7, 30.0, 33.2, 36.5, 43.1, 49.6, 56.1, 62.7, 69.2, 82.2, 95.2, 108.1, 121.0, 133.9, 146.7, 165.9, 197.7, 229.4, 260.8, 292.0, 323.0, 353.8, 384.4, 414.9, 445.1, 475.2, 505.0, 534.7, 564.2, 593.5, 622.6, 651.5, 680.3, 708.9 and 737.3 μM), PCP (0, 2.0, 3.6, 6.9, 10.2, 13.5, 16.8, 20.1, 23.4, 26.7, 30.0, 33.2, 36.5, 43.1, 49.6, 56.1, 62.7, 69.2, 82.2, 95.2, 108.1, 121.0, 133.9, 146.7, 165.9, 197.7, 229.4, 260.8, 292.0, 323.0, 475.2, 622.6, 765.5, 904.2, 1169.4, 1655.9, 2091.7, 2484.1, 2839.5, 3162.8, 3458.1 and 3729.0 μM), PHE (0, 2.0, 3.6, 6.9, 10.2, 13.5, 16.8, 20.1, 23.4, 26.7, 30.0, 33.2, 36.5, 43.1, 49.6, 56.1, 62.7, 69.2, 82.2, 95.2, 108.1, 121.0, 133.9, 146.7, 165.9, 197.7, 229.4, 260.8, 292.0, 323.0, 475.2, 622.6, 765.6, 904.2, 1169.4, 1656.0, 2091.6, 2484.1, 3162.8, 3458.1, 3729.0, and 3978.3 μM) or BHT (0, 2.0, 3.6, 6.9, 10.2, 13.5, 16.8, 20.1, 23.4, 26.7, 30.0, 33.2, 36.5, 43.1, 49.6, 56.1, 62.7, 69.2, 82.2, 95.2, 108.1, 121.0, 133.9, 146.7, 165.9 μM).
S-4
Figure S2. Plot of the quenching ratio (F0/F) for TNP, TNT, PCP, PHE and BHT at 402 nm versus their respective concentration.
TNT
PCP
PHE
Figure S3. Plot of Stern–Volmer constants for TNT, PCP or PHE quenching of MoS2 QDs as a function of emission wavelengths, and UV–Vis absorption spectra of the three structurally similar compounds in the 350–500 nm wavelength range. Other experiment conditions are as in Figure S1.
S-5
B
A
Figure S4. The hydrodynamic diameter of MoS2 QDs (A) and MoS2 QDs in the presence of TNP (B) measured by DLS method.
A
B
Figure S5. (A) PL spectra of MoS2 QDs under different conditions: (a) MoS2 QDs alone, (b) MoS2 QDs + 10 μM TNP, (c) MoS2 QDs + 10 μM TNP + 10 μM TNT, (d) MoS2 QDs + 10 μM TNP + 20 μM TNT. Other experiment conditions are as in Figure 4. (B) Selectivity of the MoS2 QDs–based PL sensor for TNP over TNT. The quenching ratio (F0/F) values are derived from PL spectral data in Figure S5A.
REFERENCES (1) Eaton, D. F. Pure Appl. Chem. 1988, 60, 1107–1114. (2) Brouwer, A. M. Pure Appl. Chem. 2011, 83, 2213–2228.
S-6
