1

Supplementary InformationA novel fluorescence turn-on probe for the selective detection of

thiophenols by caged benzooxazolidinoindocyanine

Guoxing Yin,a Ting Yu,a Tingting Niu,b Peng Yin,*a Haimin Chen,b Youyu Zhang,a Haitao Li*a and

Shouzhuo Yaoa

a Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of

Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha

410081, China.

b Key Laboratory of Marine Biotechnology of Zhejiang Province, Ningbo University, Ningbo,

Zhejiang 315211, China

E-mail address: yinpeng@hunnu.edu.cn; haitaoli@ hunnu.edu.cn

Table of Content

Experimental Section.................................................................................................................................2

Supplementary Spectra ..............................................................................................................................4

1H NMR, 13C NMR and HRMS chart........................................................................................................8

Reference .................................................................................................................................................15

Electronic Supplementary Material (ESI) for RSC Advances.This journal is © The Royal Society of Chemistry 2017

2

Experimental Section

Calculation of the detection limit (LOD)

LOD = 3σ/S

𝜎 = ∑(�̅� ‒ 𝑥𝑖)2

𝑛 ‒ 1

σ: the standard deviation of the blank solution.

𝑥 is the mean of the blank measures; 𝑥𝑖 is the values of blank measures; n is the number of tested

blank measure (n = 10)

S: the slope of the linear calibration plot between the fluorescence emission intensity and the

concentration of PhSH.

Synthesis of (E)-3-(2-hydroxyethyl)-2-(4-hydroxystyryl)-1,1-dimethyl-1H-benzo[e]indol-3-ium

(E)-10a-(4-(2,4-dinitrophenoxy)styryl)-11,11-dimeth-yl-8,9,10a,11-tetrahydrobenzo[e]oxazolo[3,2-

a]indole (probe PBO) (0.1 g, 0.19 mmol) and thiophenol (0.152 g, 0.955 mmol) were dissolved in

acetonitrile (5 mL) and deionized water (1 mL). The mixture was stirred at room temperature for 0.5 h

until no starting material was indicated by TLC. Acetonitrile was evaporated under reduced pressure,

then 15 mL of dichloromethane was added. The organic layer was separated out and washed with

saturated brine three times. Then the organic layer was dried over anhydrous Na2SO4 and concentrated

to afford the crude product, which was further purified by flash column chromatography (PE:EA = 3:1,

v/v) to afford the pink solid (20 mg, 29.2 %). 1H NMR (500 MHz, DMSO-d6) δ 9.54 (s, 1H), 7.98 (d, J

= 8.5 Hz, 1H), 7.85 (d, J = 8.2 Hz, 1H), 7.77 (d, J = 8.6 Hz, 1H), 7.49 – 7.42 (m, 1H), 7.38 (d, J = 8.5

Hz, 2H), 7.31 – 7.21 (m, 2H), 6.81 – 6.68 (m, 3H), 6.18 (d, J = 16.0 Hz, 1H), 3.97 – 3.84 (m, 1H), 3.77

– 3.67 (m, 1H), 3.53 – 3.44 (m, 1H), 3.43 – 3.35 (m, 1H), 1.68 (s, 3H), 1.26 (s, 3H). 13C NMR (126

MHz, DMSO-d6) δ 157.85, 148.41, 132.07, 130.61, 130.19, 129.67, 129.43, 129.17, 128.58, 127.75,

3

126.76, 122.88, 122.46, 122.18, 115.90, 114.78, 110.31, 63.26, 49.99, 49.18, 26.62, 21.74. It was noted

that the isolated product from the reaction between probe PBO and thiophenol was shown as a Ring On

product by NMR characterization, which was due to the dry condition.

4

Supplementary Spectra

Figure S1. The effect of volume ratio of CH3CN/PBS (10 mM, pH = 7.4) on the fluorescence

intensities changes of free probe PBO (10 μM, black column) and probe PBO (10 μM) with 10 equiv.

of PhSH (0.1 mM, red column) for 20 min.

Figure S2. (a) The time-dependence fluorescence intensity spectra of probe PBO (10 μM) towards 10

equiv. of PhSH (0.1 mM) in CH3CN-PBS (10 mM, pH = 7.4, v/v, 5:5). λex = 530 nm, λem = 580 nm. (b)

The corresponding time-dependent fluorescence intensity changes at 580 nm.

5

Figure S3. (a) Absorption spectra of the probe PBO (10 μM) to increasing concentration of PhSH in

CH3CN-PBS (10 mM, pH = 7.4, v/v, 5:5). (b)The linear changes of the absorbances of probe PBO at

558 nm as a function of PhSH concentration. [PhSH]/[PBO] = 0, 0.2, 0.4, 0.6, 0.8, 1, 1.5, 2, 2.5, 3, 3.5,

4, 4.5, 5, 5.5, 6, 7, 8, 9, 10.0.

Figure S4. (a) pH-dependent fluorescence intensity spectra of free probe PBO (10 μM) and probe PBO

(10 μM) with 10 equiv. of PhSH (0.1 mM) in CH3CN-PBS (10 mM, v/v, 5:5) with λex = 530 nm, λem =

580 nm. Slit (nm): 10.0 /10.0. (b) Profile of pH dependence of the fluorescence intensity of probe PBO

at 580 nm in the absence () and presence () of PhSH. The pH is 2, 3, 4, 5, 6, 7, 7.4, 8, 9, 10.0.

6

Figure S5. The top row is the photograph of probe PBO (10 μM) in the presence of 10 equiv. of various

analytes. The down row is the photograph of probe PBO (10 μM) in the presence of 10.0 equiv. of

PhSH upon the addition of 10 equiv. of the various analytes in CH3CN-PBS (10 mM, pH = 7.4, v/v,

5:5). From left to right and top to bottom the various analytes was HCO3-,Br-, NO3

2-, NO2-, OAc-, CO3

2-,

SO42-, SO3

2-, HSO4-, HSO3

-, S2O32-, F-, Cl-, S2O8

2-, CN-, Cys, GSH, PhSH, p-nitrophenol, NaHS, 2-

aminothiophenol, 4-chlorothiophenol, p-toluenethiol, aniline, OCl- and PO43-, respectively.

Figure S6. (a) UV–vis absorption spectra of the isolated product from the reaction between probe PBO

and thiophenol in variable mixtures of acetonitrile and PBS buffer (pH = 7.4, 10 mM) with increasing

percentage of PBS by volume from 0 to 31% at room temperature. (b) Fluorescence spectra of the

isolated product from the reaction between probe PBO and thiophenol in variable mixtures of

acetonitrile and PBS buffer (pH = 7.4, 10 mM) with increasing percentage of PBS by volume from 0 to

31% at room temperature. λex = 530 nm, λem = 580 nm, slit(nm):10/10.

7

control 0.625µmol/L 1.25µmol/L 2.5µmol/L 5µmol/L 10µmol/L0

20

40

60

80

100

120

Cel

l Via

bilit

y(%

)

Figure S7. MTT assay for the survival rate of BEL-7402 cells treated with various concentrations of probe

PBO for 24 h.

8

1H NMR, 13C NMR and HRMS chart

Figure S8. 1H NMR spectrum of compound 1 in DMSO-d6.

Figure S9. 13C NMR spectrum of compound 1 in DMSO-d6.

9

Fi

gure S10. 1H NMR spectrum of compound 2 in DMSO-d6.

Figure S11. 13C NMR spectrum of compound 2 in DMSO-d6.

10

Figu

re S12. 1H NMR spectrum of probe PBO in CDCl3.

Figure S13. 13C NMR spectrum of probe PBO in CDCl3.

11

06-Dec-201615:22:07

m/z100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000

%

0

100161206_YGX3 19 (0.325) Cm (4:29) TOF MS ES+

3.17e5524.1821

362.3274318.3013274.2749115.1214 156.0372 254.1365

521.1837401.1662

512.5068412.1827

525.1869

526.1916

527.1947690.1867568.2129 840.2582785.6191767.5869 939.4002896.4998 965.2820

N O

ONO2

NO2

Figure S14. HRMS spectrum of probe PBO.

Figure S15. 1H NMR spectrum of the isolated product from the reaction between probe PBO with

thiophenol in DMSO-d6.

12

Figure S16. 13C NMR spectrum of the isolated product from the reaction between probe PBO with

thiophenol in DMSO-d6. 06-Dec-201615:35:33

m/z100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000

%

0

100161206_YGX17 4 (0.068) Cm (4:30) TOF MS ES+

2.83e5358.1805

343.1718163.4431 299.8545228.4161

359.1925

360.1982

797.3045361.2033525.1419402.2174 461.9024 542.2717 738.3725643.5688 690.9367 843.2897 916.1907 995.1161

N O

OH

Figure S17. HRMS spectrum of the isolated product from the reaction between probe PBO with

thiophenol.

13

Figure S18. 1H NMR spectra of the isolated product in (a) DMSO/D2O = 2:1 (v/v), (b) DMSO-d6.

14

Probe λex / λem (nm) FI enhancement LOD Ref

O2NHN S

O

ONO2

O2N

NO

N

465/555 ~50 2.0×10-6 M 1

NBF2

N

NH

SO

O

O2N

NO2

444/521 ~63 3.44×10-8 M 2

SO

ONO2

O2N

HN

OEt2N O

370/515 ~280 3.0×10-8 M 3

OEt2N O

O

NH

N

O

O

ONO2

NO2

425/554 ~340 1.2×10-7 M 4

N

O

O

N N SO

OO2N

NO2383/523 ~60 1.3×10-8 M 5

O

N

HN

SO

OMeO

MeO

OMe

NO2

NO2

335/403 ~100 2.0×10-7 M 6

S

N

OO O

O2N NO2

461/494 ~165 1.8×10-9 M 7

O

NC CN

NH

SO

OO2N

NO2

490/670 ~25 1.5×10-7 M 8

O

NC CN

ONO2

NO2

560/706 ~25 7×10-8 M 9

O ON

HN

SO

O

NO2

NO2 380/535 ~700 4.5×10-9 M 10

N

N

CN

CNO

NO2

NO2

477/606 ~44 8.2×10-9 M 11

N O

ONO2

NO2 530/580 >120 7×10-9 M This work

Table S1. Summary of fluorescent probes for thiophenols.

15

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