Phenazine-based colorimetric and fluorescent sensor for the selective detection of cyanides based on supramolecular self-assembly in aqueous solution

Article abstract of DOI:10.1016/j.saa.2016.12.022

Taking advantages of both the well-known phenazine structure and the mechanism of the supramolecular self-assembly and deprotonation process, the fluorescent and colorimetric sensor (ZL) was designed and synthesized, behaving as a circulation utilization (above 10 times) receptor for selective detection of cyanide anion (CN^?) in aqueous media. Upon the addition of CN^?, the sensor displayed obvious color changes from yellow to jacinth by naked eyes and the fluorescence immediately quenched (

Full text of DOI:10.1016/j.saa.2016.12.022

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 175 (2017) 117–124
Contents lists available at ScienceDirect
Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy
journal homepage: www.elsevier.com/locate/saa
Phenazine-based colorimetric and fluorescent sensor for the selective
detection of cyanides based on supramolecular self-assembly in
aqueous solution
Hai-Li Zhang, Tai-Bao Wei, Wen-Ting Li, Wen-Juan Qu, Yan-Li Leng, Jian-Hui Zhang, Qi Lin,
⁎
You-Ming Zhang , Hong Yao
Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education of China, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical
Engineering, Northwest Normal University, Lanzhou, Gansu 730070, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 27 July 2016
Received in revised form 25 November 2016
Accepted 14 December 2016
Available online 15 December 2016
Taking advantages of both the well-known phenazine structure and the mechanism of the supramolecular self-
assembly and deprotonation process, the fluorescent and colorimetric sensor (ZL) was designed and synthesized,
behaving as a circulation utilization (above 10 times) receptor for selective detection of cyanide anion (CN−) in
aqueous media. Upon the addition of CN−, the sensor displayed obvious color changes from yellow to jacinth by
naked eyes and the fluorescence immediately quenched (b10 s). With respect to other common anions, the sen-
sor possessed high selectivity and sensitivity (0.05 μM) for cyanide anions. In addition, the test strips of ZL were
fabricated, which could serve as practical colorimetric and fluorescent sensor for “in-the-field” measurements.
© 2016 Elsevier B.V. All rights reserved.
Keywords:
Deprotonating
Cyanide sensor
Self-assembly
Dual-channel
1. Introduction
[10]. Therefore, there is special interest in the development of easy and af-
fordable methods for highly selective and sensitive detection of cyanide
The self-assembly of molecules has drawn much attention for its abil-
ity to generate excellent optical properties, which is potentially useful for
ion and molecular identification [1]. Typical driving forces for the self-as-
sembly are hydrogen bonding, π-π stacking, polar-nonpolar and charge
transfer [2]. Phenazine and its derivatives could easily form the self-as-
sembly of π-conjugated system owing to their big rigid structure [3].
The π-cores of phenazine derivatives will tune certain properties when
they were modified by the amino, dialkylamino, hydroxy, nitro and
other functional groups [4]. Therefore, they often were used to recognize
ions and neutral molecular for these properties [5]. Meanwhile, they also
are important and versatile building blocks which have been extensively
designed to develop the sensors and biosensors over the years [6].
As a highly toxic anion, cyanide (CN−) has drawn strong interest due
to its harmful to environment and human body but the indispensability of
chemical industry [7]. Even trace amounts of cyanide might result in ex-
tremely damage to many biological functions, such as leading to vomiting,
convulsion, loss of consciousness, and eventual death [8]. The maximum
acceptable level of cyanide in drinking water is only 1.9 μM by the
World Health Organization (WHO) [9]. However, the release of cyanide
is unavoidable for that it was widely used in many chemical processes
anion [11]. Many manners have been proposed to detect cyanide, for ex-
ample, chromatography [12], electrochemical [13], and titrimetric [14].
Among all these manners, fluorescence spectrometry and naked-eye de-
tection methods are particularly attractive due to their easier operation,
low cost, high sensitivity and selectivity [15].
Considering all these aspects and also as a part of our research interest
in molecular recognition [16]. We synthesized a phenazine derivative ZL
(Scheme 1), which could high sensitivity and selectivity CN− based on the
fluorescent and colorimetric dual-channel in aqueous solution. After addi-
tion of the CN−, with the deprotonation process occurring, the intermo-
lecular hydrogen bonds were broken and then the supramolecular self-
assembly was disintegrated. It appeared a remarkable ON-OFF type fluo-
rescent signaling behavior and an obvious color changes. Meanwhile,
other common anions had no influence on the response of CN−. This sen-
sor also served as a recyclable component in sensing materials and the
test strips were fabricated, which could be treated as a convenient and ef-
ficient CN− test for on-site and at real-time measurement.
2. Experimental Section
2.1. Materials and Physical Methods
⁎
Corresponding author.
E-mail addresses: weitaibao@126.com (T.-B. Wei), zhangnwnu@126.com
All reagents and solvents were commercially available at analytical
(Y.-M. Zhang).
grade and were used without further purification. 1H NMR and 13C
http://dx.doi.org/10.1016/j.saa.2016.12.022
1386-1425/© 2016 Elsevier B.V. All rights reserved.

118
H.-L. Zhang et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 175 (2017) 117–124
Scheme 1. Synthetic procedures for receptor ZL.
2.3. General Procedure for Fluorescence Spectra Experiments
All fluorescence spectroscopy was carried out just after the addition
of tetrabutylammonium salt of anions (F−, Cl−, Br−, I−, AcO−, H2PO−4
,
HSO−4 and ClO−4 ) and sodium salt of anions (CN−, N3−, HS−, S2−, NO−2
and SCN−) in DMSO/H2O (7:3, v/v) solution, while keeping the ligand
concentration constant (2.0
5301spectrometer.
× a Shimadzu RF-
10−5 M) on
2.4. General Procedure for 1H NMR Experiments
For 1H NMR titrations, the sensor of stock solutions was prepared in
DMSO-d6, the cyanide anion was prepared in D2O. Aliquots of the two
solutions were mixed directly in NMR tubes.
2.5. Synthesis of ZL
2,3-Diaminophenazine (0.42 g, 2.0 mmol), benzaldehyde (0.233 g,
2.2 mmol) and five drops acetic acid (AcOH) were combined in 85 °C ab-
solute DMF (20 ml) (Scheme 1). The solution was stirred and reflux for
8 h, after cooling to room temperature, the brown precipitate was
filtrated, washed with hot absolute ethanol three times, and then re-
crystallized with DMF to get brown powdery product ZL. The TGA (ther-
mogravimetric analysis, N2) revealed that ZL had a remarkable thermal
stability, with nearly weight loss observed within 300 °C (Fig. S10).
ZL: yield: 80%; m.p. N300 °C; 1H NMR (DMSO-d6, 600 MHz) δ 13.45
(s 1H), 8.52 (s 1H), 8.38–8.37 (d 2H), 8.26–8.23 (d 3H), 7.89–7.88 (d
2H), 7.67–7.66 (d 3H). 13C NMR (DMSO-d6, 150 MHz) δ 159.90,
149.25, 142.25, 142.08, 140.88, 140.86, 140.62, 140.23, 132.22, 130.16,
129.87, 129.86, 129.60, 129.43, 129.23, 128.18, 115.23, 109.87, 106.29;
Fig. 1. XRD diagram of ZL.
NMR spectra were recorded at a Mercury-400BB spectrometer at
400 MHz. Chemical shifts are reported in ppm downfield from
tetramethylsilane (TMS, δ scale with solvent resonances as internal
standards) Melting points were measured on an X-4 digital melting-
point apparatus (uncorrected). Infrared spectra were performed on a
Digilab FTS-3000 FT-IR spectrophotometer.
2.2. General Procedure for UV–Vis Experiments
All UV–vis spectroscopy was carried out just after the addition of
IR (KBr cm−1) v: 3115 (N\\H), 1693 (C = N); ESI-MS m/z (M + H+
)
tetrabutylammonium salt of anions (F−, Cl−, Br−, I−, AcO−, H2PO−4
,
Calcd for C19H12N4 296.1135; Found 297.114.
HSO−4 and ClO−4 ) and sodium salt of anions (CN−, N3−, HS−, S2−, NO−2
and SCN−) in DMSO/H2O (7:3, v/v) solution, while keeping the ligand
concentration constant (2.0 × 10−5 M) on a Shimadzu UV-2550
spectrometer.
To better investigate the reaction mechanism of ZL and CN−, we
achieved the assembling structure of ZL from the X-ray diffraction
(XRD) and the crystal structure (Figs. 1 and 2). We obtained a d-spacing
of 3.51 Å by 2θ = 25.33° from the XRD, it suggesting that it existed π-π
Fig. 2. Different perspectives of ZL's crystal structure.

H.-L. Zhang et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 175 (2017) 117–124
119
Fig. 3. Cyclic voltammetry curves of ZL (a) and ZL − CN− (b) in DMSO solution containing 0.1 M NaNO3 electrolyte. Scanning rate: 50 mV/s.
and the crystal structure provided strongly evidence for the proposal
of mechanism.
Table 1
Electrochemical properties of ZL and ZL − CN−
.
The CV (cyclic voltammetry) curves of ZL and ZL − CN− were
researched in DMSO (with 0.1 M NaNO3) using Ag/AgCl as reference
electrode (Fig. 3 and Table 1). The two dissolved compounds showed
different redox behaviors at the same testing conditions. The onset oxi-
dation potentials for ZL and ZL − CN− were −0.82 V and −0.52 V,
onset
onset
Compounds
E
(V)a
E
(V)a LUMO (eV)b HOMO (eV)c
λ
max/nmd
oxd
red
ZL
−0.82
−0.52
−0.18
−0.72
−4.22
−3.68
−3.58
−3.88
402
428
ZL + CN−
a
Obtained from CV curves in NaNO3.
b
c
onset
ELUMO = − e(4.40 - E
EHOMO = − e(4.40 - E
) eV.
) eV.
red
onset
which consistent with the HOMO energy levels of −3.58 eV and
oxd
onset
d
Determined in DMSO/H2O (7:3, v/v) solution.
3.88 eV respectively by the equation EHOMO = −[4.4 + E
] eV. The
oxd
onset reduction potentials of ZL and ZL − CN− were −0.18 and
stacking between molecular of ZL. Meanwhile, the crystal structure
gave us valuable information on the assembly according to image con-
trast across the sample. The π-cores align antiparallel with phenazine
group placed nearly parallel to the π-surface while the other side
group pointed away from the π-surface. Imine nitrogen in the imidazole
core are hydrogen-bonded to tertiary amine in the imidazole at another
molecular. The amazing corresponding of the X-ray diffraction (XRD)
−0.72 eV, which consistent with the LUMO energy levels of −4.22
onset
and −3.68 eV according to the equation ELUMO = −[4.4 + E
] eV
red
[17]. At the same time, based on the equation Egap = ELUMO − EHOMO
eV, we worked out the bandgap energy (Egap) of ZL and ZL − CN−
were −0.65 and −0.2 eV respectively, which correspond to the red
shifts at the UV−vis spectra. This study also indicated that ZL − CN−
could show better stability in electronic devices than ZL.
Fig. 4. (a) Absorbance spectra of ZL upon the addition of different anions (F−, Cl−, Br−, I−, AcO−, H2PO−4 , HSO−4 , ClO4−, CN− and SCN−) in DMSO/H2O (7:3, v/v) solutions. (b) Color changes
of ZL with various anions.

120
H.-L. Zhang et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 175 (2017) 117–124
Fig. 5. (a) Fluorescent spectra of ZL upon the addition of different anions (F−, Cl−, Br−, I−, AcO−, H2PO−4 , HSO−4 , ClO4−, CN− and SCN−) in DMSO/H2O (7:3, v/v) solutions. (b) Color changes
of ZL with various anions.
We carried out a series of recognition experiments to study its spe-
cial recognition ability. The colorimetric and fluorescent sensing abili-
ties were primarily investigated by adding various anions to the
DMSO/H2O solution (7:3, v/v). As shown in Fig. 4b, the sensor immedi-
ately responded with obvious color changes (from yellow to jacinth)
when CN− was added to the ZL solution. In the corresponding UV–vis
spectra, the absorbance peak at 402 nm was red shift to 428 nm (Fig.
4a). As shown in Fig. 5a, a yellow fluorescence at 542 nm appeared
when the solution of sensor ZL was excited at 403 nm. Upon the addi-
tion of CN−, the fluorescence emission remarkably decreased (Fig. 5b).
solution, neither significant color or fluorescence change was observed.
All these facts might indicate that ZL occurred a deprotonation process
after addition of the CN−, which broken the intermolecular hydrogen
bonds and then bringing to disintegrating of the supramolecular self-as-
sembly. The facts also confirmed that ZL can be capable of selectivity
and sensitivity detection CN− in DMSO/H2O (7:3, v/v) solution (Fig. 6).
Achieving high selectivity for the analyte of interest over a complex
background of potentially competing species was a challenging task in
sensor development. Fig. 5, Fig. 7 and Fig. S4 illustrated the fluorescence
and UV–vis response of compound ZL to CN− in the presence of other
However, when other anions solution (including F−, Cl−, Br−, I−
,
anions (F−, Cl−, Br−, I−, AcO−, H2PO−4 , HSO4−, ClO4−, N−3 , HS−, S2−
,
AcO−, H2PO−4 , HSO−4 , ClO4− and SCN−) were added to the sensor ZL
NO−2 , and SCN−) in DMSO/H2O (7:3, v/v) solution. Form the bar
Fig. 6. Fluorescent spectra of ZL and ZL–CN− in the presence of 50 equivalents of various
anions in DMSO/H2O (7:3, v/v) solution (λex = 403 nm).
Fig. 7. UV–vis spectra of ZL and ZL–CN− in the presence of 50 equivalents of various anions
in DMSO/H2O (7:3, v/v) solution (λ = 428 nm).

H.-L. Zhang et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 175 (2017) 117–124
121
(b1.9 × 10−6 M). This result also showed ZL has higher sensitive for cy-
anide anion compared with other reported CN− sensors (Table S1).
To further investigate the reaction mechanism, 1H NMR titration,
was used to illustrate the characteristic structural changes occurring
upon interaction with CN−. As shown in Fig. S3, the 1H NMR chemical
shifts of ZL shown a strong peaks at 13.45 ppm, which could be assigned
to the N\\H proton. After addition of 0.1 equivalent of CN−, the N\\H
peak at 13.45 ppm disappeared. At the same time, the other proton sig-
nals from 7.60 to 8.60 ppm have a significant upfield shift. Thus, we can
indicate that cyanide could take the H proton away via deprotonating
from the \\NH moiety of ZL causing the intermolecular hydrogen
bond disruption and the supramolecular self-assembly disintegration,
which lead to the fluorescent quenched and the absorbance peak red
shift.
In order to quantify the reaction ratio between ZL and CN−, the fluo-
rescent Job's plot (Fig. S2) was conducted by varying the concentration
of both the receptor and the CN− ion. The break point appears at the
mole fraction of 0.5 which indicates the reaction ratio of ZL and CN−
is 1:1. It was further confirmed by the appearance of a peak at m/z
297.11 and m/z 295.14 which can be assignable to [ZL + H+] and
[ZL − H+] in the ESI-MS (Fig. S1 and Fig. 10).
Fig. 8. Fluorescence spectra of ZL in the presence of different concentrations of CN− in
DMSO/H2O (7:3, v/v) solution. Insert: a plot of fluorescence intensity depending on the
concentration of CN− in the range from 0 to 19.12 equivalents (λex = 403 nm).
Above all of these tests, we rationally inferred the reaction mecha-
nism is that the self-assembly which containing the intermolecular hy-
drogen bonds and π-π stacking of phenazine cores was destroyed after
added CN− by the deprotonating process (Fig. 11).
The reversibility of the sensor function was tested by addition of
HClO4 to the cyanide-sensor complex. Impressively, upon addition of
HClO4, CN− was removed from the ZL–CN− complex and the fluores-
cence intensity recovered to the original strength. With addition of
CN− to the ZL–CN−– HClO4 complex, the fluorescence intensity sharply
decreased (Fig. 12). The fluorescence emission of the tested solution
performed alternate quenching and reviving processes with addition
of CN− and HClO4 in turn.
The pH value of system is often considered as a significant influence
factor on interactions. As shown in Fig. 13, ZL–CN− was nearly non fluo-
rescence from pH 8–13, and the fluorescence intensity was drop mark-
edly at pH = 7. Therefore, the sensor can available for a wide pH range
of 7.0–13.0 to detect CN−.
To investigate the practical application of ZL, we made a comparison
test strips. Test strips were prepared by immersing filter paper into a
DMSO solution of ZL (2 × 10−5 M) and then drying them in air. As
shown in Fig. 14, when CN− was added on the test kits, the obvious fluo-
rescence quenched was observed. Therefore, the test strips could conve-
niently detect.
diagram, we could easily consider that the effects on emission and ab-
sorption intensity of ZL and CN− solutions upon addition of various an-
ions were almost negligible. Therefore, it was clear that other ions'
interference were negligible small during the detection of CN−. These
results further suggested that ZL could be used as a sensor for CN−
over a wide range of anions.
Fluorescence and UV–vis titration were performed to gain insight
into the recognition properties of receptor ZL as CN− sensor. In fluores-
cence spectrum (Fig. 8), upon addition CN− to receptor ZL, the emission
at 542 nm gradually decreased. Concomitantly, in UV–vis spectra (Fig.
9), with the gradual addition of CN−, the absorption at 402 nm de-
creased; while the absorption at 428 nm increased until it reached a
limiting value. Moreover the presence of one isosbestic point at
408 nm indicated that sensor ZL reacted with cyanide anions.
The colorimetric and fluorometric detection limits of sensor ZL for
CN− were also tested. As shown in Fig. S5 and Fig. S6, the change of fluo-
rescence intensity and absorbance intensity ratio were linear with in-
creasing CN− concentration. The detection of ZL for CN− calculated on
the basis of 3σ/m [18] were 7.0 × 10−8 M for fluorescence and
5.0 × 10−8 M for absorption spectra change respectively, which are
both far lower than the index of WHO for CN− in drinking water
3. Conclusion
In summary, we have designed and synthesized the fluorescent and
colometric sensor ZL for reversible recognition cyanide ions with the su-
pramolecular self-assembly and the deprotonation mechanism in aque-
ous solution. Taking advantage of the outstanding competitive ability
and high sensitivity than other sensors, this work provided a novel ap-
proach for the selective recognition of CN−. Thus, this work might stim-
ulate the scientist interest for exploring new sensors based on the
supramolecular self-assembly mechanism. Taking advantage of the re-
cyclable of ZL, wide pH range application and the successful application
in paper testing, we believe that the test strips could act as a convenient
and efficient CN− test kits.
Acknowledgment
This work was supported by the National Natural Science Founda-
tion of China (nos. 21161018; 21262032; 21574104), the Program for
Chang Jiang Scholars and Innovative Research Team in University of
Ministry of Education of China (no. IRT1177).
Fig. 9. UV–vis spectra of ZL in the presence of different concentrations of CN− in DMSO/
H2O (7:3, v/v) solution. Insert: a plot of absorbance depending on the concentration of
CN− in the range from 0 to 15.14 equivalents respectively at 402 nm and 428 nm.

122
H.-L. Zhang et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 175 (2017) 117–124
Fig. 10. The ESI–MS of ZL–CN−
.
(c) J. Xu, S.B. Sun, Q. Li, Y. Yue, Y.D. Li, S.J. Shao, Anal. Chim. Acta 849 (2014) 36–42;
(d) F.J. Huo, C.X. Yin, Y.T. Yang, J. Su, J.B. Chao, D.S. Liu, Anal. Chem. 84 (2012)
2219–2223;
(e) S. Erdemir, O. Kocyigit, Sensors Actuators B 221 (2015) 900–905;
(f) C.J. Gao, X.J. Jin, X.H. Yan, P. An, Y. Zhang, L.L. Liu, H. Tian, W.S. Liu, X.J. Yao, Y. Tang,
Sensors Actuators B 176 (2013) 775–781.
Appendix A. Supplementary data
Supplementary data to this article can be found online at http://dx.
doi.org/10.1016/j.saa.2016.12.022.
[6] (a) J.Y. Hu, R. Liu, X.L. Zhu, X. Cai, H.J. Zhu, Chin. Chem. Lett. 26 (2015) 339–342;
(b) C.Y. Wang, G. Li, Q.C. Zhang, Tetrahedron Lett. 54 (2013) 2633–2636;
(c) S.M.S. Chauhan, T. Bisht, B. Garg, Tetrahedron Lett. 49 (2008) 6646–6649;
(d) B.B. Shi, K.C. Jie, Y.J. Zhou, J. Zhou, D.Y. Xia, F.H. Huang, J. Am. Chem. Soc. 138
(2016) 80–83;
(e) J. Li, Q. Zhang, ACS Appl. Mater. Interfaces 7 (2015) 28049–28062;
(f) P.Y. Gu, Z.L. Wang, Q. Zhang, J. Mater. Chem. B 4 (2016) 7060–7074.
[7] (a) K.W. Kulig, Atlanta. (1991);
References
[1] (a) M.J.E. Resendiz, J.C. Noveron, H. Disteldorf, S. Fischer, P.J. Stang, Org. Lett. 6
(2004) 651–653;
(b) W.J. Yuan, L. Huang, Q.Q. Zhou, G.Q. Shi, ACS Appl. Mater. Interfaces 6 (2014)
17003–17008.
[2] X. Zarate, E. Schott, RSC Adv. 4 (2014) 15642–15649.
[3] (a) D.C. Lee, B. Cao, K. Jang, P.M. Forster, J. Mater. Chem. 20 (2010) 867–873;
(b) V.S.S. Mosali, G.A. Bowmaker, M. Gerard, P.A. Kilmartin, J.T. Sejdicb, Z.D.
Zujovicb, Polym. Int. 64 (2015) 1135–1141;
(b) S.S. Sun, A.J. Lees, Chem. Commun. 36 (2000) 1687–1688;
(c) J. Li, J. Gao, W.W. Xiong, P.Z. Li, H. Zhang, Y. Zhao, Q. Zhang, Chem. Asian. J. 9
(2014) 121–125.
(c) S. Biradar, Y. Shigemitsu, Y. Kubota, K. Funabiki, H. Satoc, M. Matsui, RSC Adv. 4
[8] (a) P. Anzenbacher Jr., D.S. Tyson, K. Jursíková, F.N. Castellano, J. Am. Chem. Soc. 124
(2014) 59387–59396;
(2002) 6232–6233;
(b) R. Koenig, Science 287 (2000) 1737–1738.
[9] Guidelines for Drinking-Water Quality, World Health Organization, Genova 12
(d) J.F. Zhao, Y. Liu, J.B. Soh, Y.X. Li, R. Ganguly, K.Q. Ye, F. Huo, L. Huang, A.I.Y. Tok,
J.S.C. Loo, Q. Zhang, Tetrahedron Lett. 53 (2012) 6044–6047;
(e) J. Zhao, G. Li, C. Wang, W. Chen, S.C.J. Loo, Q. Zhang, RSC Adv. 3 (2013)
9653–9657.
(2011) 342–344.
[10] Q. Zhang, J. Zhang, H.J. Zuo, C.Y. Wang, Y.J. Shen, Tetrahedron 72 (2016) 1244–1248.
[11] X.B. Cheng, H. Li, F. Zheng, Q. Lin, Y.M. Zhang, H. Yao, T.B. Wei, Dyes Pigments 127
(2016) 59–66.
[4] C.J. Tonzola, M.M. Alam, W. Kaminsky, S.A. Jenekhe, J. Am. Chem. Soc. 125 (2003)
13548–13558.
[5] (a) F.J. Huo, J. Su, Y.Q. Sun, C.X. Yin, J.B. Chao, Chem. Lett. 39 (2010) 738–740;
(b) Y.A. Son, Y.M. Park, S.Y. Park, C.J. Shin, S.H. Kim, Dyes Pigments 73 (2007) 76–80;
[12] A. Safavi, N. Maleki, H.R. Shahbaazi, Anal. Chim. Acta 503 (2004) 213–221.
[13] Y.G. Timofeyenko, J.J. Rosentreter, S. Mayo, Anal. Chem. 79 (2007) 251–255.

H.-L. Zhang et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 175 (2017) 117–124
123
Fig. 11. The possible sensing mechanism of ZL reaction with CN−
.
[14] P.J. Anzenbacher, D.S. Tyson, K. Jursikova, F.N. Castellano, J. Am. Chem. Soc. 124
(2002) 6232–6233.
(c) B.B. Shi, P. Zhang, T.B. Wei, H. Yao, Q. Lin, Y.M. Zhang, Chem. Commun. 49 (2013)
781–7814;
[15] (a) S.T. Wang, Y.W. Sie, C.F. Wan, A.T. Wu, J. Lumin. 173 (2016) 25–29;
(b) J.J. Li, W. Wei, X.L. Qi, G.C. Zuo, J.K. Fang, W. Dong, Sensors Actuators B 228
(2016) 330–334;
(c) H.J. Lee, H.J. Kim, Tetrahedron Lett. 53 (2012) 5455–5457.
[16] (a) Y.M. Zhang, Q. Lin, T.B. Wei, X.P. Qin, Y. Li, Chem. Commun. 45 (2009)
6074–6083;
(d) H.B. Yu, Q. Zhao, Z. Jiang, J.G. Qin, Z. Li, Sensors Actuators B 148 (2010) 110–116;
(e) Q. Zeng, P. Cai, Z. Li, J.G. Qin, B.Z. Tang, Chem. Commun. 9 (2008) 1094–1096.
[17] (a) G. Li, Y. Wu, J. Gao, J. Li, Y. Zhao, Q. Zhang, Chem. Asian. J. 8 (2013) 1574–1578;
(b) G. Li, Y. Wu, J. Gao, C. Wang, J. Li, H. Zhang, Y. Zhao, Y. Zhao, Q. Zhang, J. Am.
Chem. Soc. 134 (2012) 20298–20301.
[18] Analytical Methods Committee, Analyst 112 (1987) 199–204.
(b) Q. Lin, X. Liu, T.B. Wei, Y.M. Zhang, Chem. Asian. J. 8 (2013) 3015–3021;
Fig. 12. The emission spectra showing the reversible complex between ZL–CN− and
HClO4.
Fig. 13. ZL–CN− in DMSO/H2O (7:3, v/v) at different pH values.

124
H.-L. Zhang et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 175 (2017) 117–124
Fig. 14. Photographs of ZL and the mixture of ZL and different anions on the test papers in the DMSO/H2O (7:3, v/v) solution irradiation at 365 nm.