Facile synthesis of a water-soluble fluorescence sensor for Al3 + in aqueous solution and on paper substrate

Article abstract of DOI:10.1016/j.saa.2016.10.004

In this study, a facile water-soluble fluorescence sensor 2-((2-hydroxybenzylidene)-amino)-2-(hydroxymethyl)propane-1,3-diol (ST) was synthesized via one-step reaction, and its fluorescence sensing performance for Al^{3 +} both in aqueous solution

Full text of DOI:10.1016/j.saa.2016.10.004

Facile synthesis of a water-soluble fluorescence sensor for Al3 + in aqueous
solution and on paper substrate
Tianqi Liu, Xuejuan Wan, Yunsheng Dong, Weibin Li, Lisi Wu, Hang
Pei, Youwei Yao
PII:
DOI:
Reference:
S1386-1425(16)30585-6
doi:10.1016/j.saa.2016.10.004
SAA 14703
To appear in:
Received date:
Revised date:
Accepted date:
24 July 2016
28 September 2016
7 October 2016
Please cite this article as: Tianqi Liu, Xuejuan Wan, Yunsheng Dong, Weibin Li, Lisi Wu,
Hang Pei, Youwei Yao, Facile synthesis of a water-soluble fluorescence sensor for Al3
in aqueous solution and on paper substrate, (2016), doi:10.1016/j.saa.2016.10.004
+
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ACCEPTED MANUSCRIPT
3
+
Facile synthesis of a water-soluble fluorescence sensor for Al in
aqueous solution and on paper substrate
ac
b *
a
ac
Tianqi Liu, Xuejuan Wan, Yunsheng Dong, Weibin Li,
b
b
a *
Lisi Wu, Hang Pei, Youwei Yao,
a
Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China.
Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials
b
Science and Engineering, Shenzhen University, Shenzhen 518060, PR China.
c
Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
Corresponding authors.
E-mail: yaoyw@sz.tsinghua.edu.cn (Youwei Yao)
wanxj@szu.edu.cn (Xuejuan Wan)
1

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Abstract
In this study, a facile water-soluble fluorescence sensor 2-((2-hydroxybenzylidene)-
amino)-2-(hydroxymethyl)propane-1,3-diol (ST) was synthesized via one-step reaction, and its
3
+
fluorescence sensing performance for Al both in aqueous solution and on paper substrate was
evaluated. The results showed that ST exhibited an specific fluorescence “turn-on” response to
3
+
Al over other cations in aqueous solution as well as on the test paper. The limit of detection was
-7
found to be 3.2 × 10 M, which revealed that the obtained Schiff-base based fluorescence
chemosensor ST possessed a great potential for the rapid, quantitative and qualitative detection of
3
+
Al .
3
+
Key words: one-step reaction; water-soluble; fluorescence sensor; Al ; paper substrate
2

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1. Introduction
Fluorescent chemosensor is widely used as a significant and effective approach to spy on
metal ions owing to its simplicity, high sensitivity, selectivity and rapid response time.[1-10]
Aluminium which widely exists in the environment and human activities is believed to retard plant
growth and is implicated as a causative factor of Alzheimer's disease and Parkinson's
3
+
disease.[11-19] As aluminium normally takes the form of Al ion in the body and environment,
3
+
the exploration of sensitive and selective Al probe is crucial to the environmental monitoring and
3
+
human health maintaining.[20-26] But a majority of the reported Al -selective chemosensors
have limitations including harsh reaction conditions, tedious synthetic/purification procedures, and
relatively low product yield,[27, 28] which are inconvenient for their practical applicability in
aqueous solutions. In addition, most of the fluorescence chemosensors are studied in pure organic
(such as DMSO and THF) or organic-water mixed solutions due to their insufficient water
3
+
solubility.[29] Other problems existing in the detection of Al are the lack of spectroscopic
characteristics, poor coordination ability and strong hydration ability.[30-32] Besides, the
3+
3+
3+
3+
3+
detection of Al is usually interfered by other trivalent ions like In , Ga , Fe and Cr owing to
3
+
the similar electron configuration in the recognition process.[33-35] Thus, Al sensor with
improved properties is still in high demand.
Schiff-bases are attractive owing to its versatile and powerful electronic and photophysical
properties as chemosensors.[36-38] Schiff-base is a kind of well-known ligand for metal ions and
its derivatives containing fluorescent chromophore are also appealing tools for optical sensing of
metal ions.[39, 40] During the last decades, particular attention has been paid to the study of
Schiff-base based fluorescence chemosensors due to their generally one-step synthesis with high
yield.[41] Meanwhile, some Schiff-base-metal complexes were reported to have antitumor,[42]
antioxidative[43] and flame retardant activities[44]. Currently, the main shortcoming of
Schiff-base based chemosensors are their low water solubility.[45, 46] In this communication, we
3
+
report a water-soluble sensitive fluorescence sensor for Al ions with excellent selectivity, which
can also be economically synthesized by one-step procedure using simply available
salicylaldehyde and tris(hydroxymethyl)methyl aminomethane (Tris) as precursors. The high
water solubility of the obtained fluorescent chemosensor is originated from the strategically
3

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introduction of hydrophilic molecular Tris. At the same time, N and O hard Lewis base donor sites
3
+
in Tris moiety render the probe with excellent binding affinity to hard Lewis acid such as Al ,
which allow sensitive and selective fluorescence sensing toward the target ion.[27, 47, 48]
2. Experimental
2.1 Materials and instruments
Salicylaldehyde and tris(hydroxymethyl)methyl aminomethane were obtained from
aladdin-reagent. All the solvents were purchased from Shanghai Chemical Reagent Co. and used
as received. UV-Vis spectra were recorded with SCINCO S-4100. A HORIBA Jobin Yvon SPEX
spectro fluorimeter was used for fluorescence measurements. The excitation wavelength was 310
1
13
nm and the spectra was recorded in the range 350-600 nm. Both H NMR (400 MHz) and
C
NMR spectra (100 MHz) of the compound were recorded on a Burker AVANCE-III in d-DMSO or
D O with tetramethylsilane as the internal standard. The high-resolution mass spectra (HR-MS)
2
were performed on ABI QSTAR Elite. The Fourier transform infrared spectroscopy (FTIR)
spectra were measured by an EQUINOX 55 (Bruker) spectrometer with the KBr pellet technique
−
1
ranging from 500 to 4000 cm .
2.2 Synthesis
The fluorescence chemosensor 2- ((2-hydroxybenzylidene) -amino)-2- (hydroxymethyl)
propane-1,3-diol (ST) was synthesized via one-step condensation reaction between
salicylaldehyde and Tris at room temperature[44] with a yield of 85%, as is illustrated in
Scheme 1. A ethanol solution (10.0 mL) of tris(hydroxymethyl)methyl aminomethane (1.2 g,
10.0 mmol) was added dropwise to the solution (10.0 mL) of salicylaldehyde (1.2 g, 10.0 mmol)
in ethanol under stirring. Then the mixture was stirred for 6 h at room temperature to afford a
yellow solution. ST was recovered by concentrating the yellow solution, then filtering and
washing the yellow solid product with ethanol for three times. Molecular structure of ST was
1
confirmed by H NMR (400 MHz, DMSO) δ 14.52 (s, 1H), 8.56 (s, 1H), 7.40 (d, J = 7.6 Hz,
1H), 7.27 (t, J = 7.8 Hz 1H), 6.79 (m, 2H), 4.73 (t, J = 5.4 Hz, 3H), 3.61 (d, J = 5.4 Hz, 6H).,
1
3
C NMR (100 MHz, DMSO) δ 164.88, 163.70, 132.74, 132.59, 119.04, 117.82, 117.63, 67.51,
+
+
6
1.95.and HR-MS analysis (calcd for C H NO [ST+H ] : 226.1079; found: 226.1073) (Fig.
11 16 4
S1–S3).
4

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2.3 Testing and detecting methods
-3
+
+
2+
Various metal ions stock solution (10 M) of the nitrate and chloride salts of Na , K , Mg ,
2
+
2+
2+
2+
2+
2+
2+
3+
3+
3+
3+
3+
Ni , Ba , Zn , Cd , Hg , Cu , Pb , In , Ga , Al , Fe and Cr ion were prepared in water.
Test solution was prepared with calculated amount of ST solution and a certain volume of each
metals stock solution in 5.00 mL tube, and then diluted to 3.00 mL. After mixing fluorescent
sensor and metal ions or 30 min, the absorption and fluorescence spectra of ST were recorded at
room temperature. Meanwhile, in order to evaluate the potential application of chemosensor ST
3
+
for Al in real samples, tap water has also been utilized to prepare the stock solution, and the
testing procedure was similar with those of deionized water. FT-IR sample was prepared by
mixing AlCl .6H O and sensor ST then dried in vacuum. HRMS sample was prepared by mixing
3
2
3+
solution of sensor ST and Al in methanol.
3. Results and discussion
The fluorescence response behavior of ST (50.0 μM) was examined in the absence and
presence of various metal ions (250.0 μM) in Tris buffer (10.0 mM, pH = 7.0) (Fig. 1). ST alone
+
shows no significant fluorescence emission and is silent toward most of the metal ion such as Na ,
+
2+
2+
2+
2+
2+
2+
2+
2+
3+
3+
3+
3+
K , Mg , Ni , Ba , Zn , Cd , Hg , Cu , Pb , In , Ga , Fe and Cr after excitation at 310
3+
nm. Upon the addition of Al , ST exhibits a prominent fluorescence emission enhancement
accompanied by a red shift of 54 nm from 405 nm to 459 nm. Simultaneously, the color of the
solution changes from colorless to blue under UV lamp, which could be easily visualized by naked
eye. This unique selectivity of ST is attributed to the smaller ionic radius and higher charge
3+
density of Al , which allows a suitable coordination geometry between the chelating agent ST and
3
+
Al .[49] Imines are generally known to be poorly fluorescent, in part due to isomerization of the
C＝N double bond in the excited state and in part due to photo-induced electron transfer (PET)
process. The lone pair of electrons on the nitrogen atom quenched the fluorescence of free ST
because electrons could be freely transferred from the donor to the excited state of the fluorophore.
However, the above-mentioned PET process can be totally restrained in the case when the electron
donating ability of the nitrogen atom is reduced by complexation with metal ions. As a result, a
dramatically increased fluorescence emission at 459 nm of ST is observed with the addition of
3
+
Al .The observed fluorescence enhancement may be also attributed to the formation of a chelate
complex between metal ions and ST, causing the chelation-enhanced fluorescence (CHEF)
5

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effect.[50, 51]
3
+
The chemosensing properties of ST (50.0 μM) toward Al are evaluated by fluorescence
titration and UV-Vis titration experiments in Tris buffer (10.0 mM, pH = 7.0). As shown in Fig. 2,
3+
the fluorescence intensity at 459 nm enhances gradually with the increasing concentration of Al
3
+
and then gradually levels off as the concentration of Al is greater than 50.0 μM, indicating that
3
+
the recognition molar ratio of probe ST to Al might be 1: 1. The inset in Fig. 2 shows a linear
3+
2
range for Al detection between 0 and 50.0 μM (R =0.9970) and detailed data is provided in
3
+
-7
Table S1. The limit of detection (LOD) for Al is determined as 3.2 × 10 M, according to the
equation LOD= 3Sb /S, where Sb is the standard deviation of the blank solution, S is the slope of
1
1
the calibration curve.[7, 52, 53] The result indicates that the LOD of ST is comparable to the
3
+
-1
recommended maximum contaminant level (MCL) for Al in drinking water (0.2 mg L , 7.4×
-6
3+
1
0 M). We then investigate the changes in the UV-Vis absorbance of ST upon treatment with Al
(
Fig. S4 and Fig. S5). The absorbance peak centered at 255 nm and 327 nm decreases after the
3+
addition of Al , while absorbance peak centered at 309 nm gradually enhances with an isosbestic
3
+
point at 317 nm, indicating the formation of a new complex between ST and Al . The inset in Fig.
3
+
S4 shows the dependence of UV-Vis absorbance at 255, 309 and 327 nm on Al concentration.
3+
Plotting absorbance versus Al concentration all affords a good linear relationship from 0 to 50.0
2
μM (R = 0.9868, 0.9966 and 0.9922 respectively).
Possible interference of potential competing species is tested in order to further check the
3
+
practical applicability of ST as an Al -selective fluorescence chemosensor in complicated
3
+
background. For this purpose, ST is treated with 1.0 equiv of Al in the presence of 5.0 equiv of
3
+
other metal ions. Competitive ions are first added into the solution, and Al is added 20 minutes
3
+
later. The results in Fig. 3 shows that there is no interference for the detection of Al in the
3
+
3+
3+
3+
presence of other ions even in the presence of typical competitive ions In , Ga , Fe and Cr .
2
+
2+
Cu and Pb quenches about 18% and 15% of the original fluorescence intensity respectively,
3
+
however, ST still has sufficient “turn-on” ratios for the detection of Al in the presence of them.
3
+
These results indicate that probe ST possesses excellent detection selectivity for Al over other
competing metal ions.
3
+
The pH effect on the assay is conducted as shown in Fig. S6, without the addition of the Al
ion, no fluorescence change at 459 nm is observed with pH values ranging from 1 to 14. The
6

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3+
addition of Al , however, leads to an obvious fluorescence enhancement over a pH range from 5.0
to 7.0. As the environmental alkalinity increased, the fluorescence intensity decreased greatly
3
+
because the formation of Al(OH) reduces the concentration of Al in the solution. Speaking of
3
the real sample, a sample with tap water background is also detected to evaluate the potential
3+
3+
application of ST in detecting Al . Al was deliberately introduced to simulate contaminated tap
water. As shown in Fig. S7 and Fig. S8, the fluorescence intensity shows an upward trend linearly
2
3+
(
R = 0.9977) upon the addition of Al (0–50 μM). The result indicates the suitability of this
3+
sensor for the determination of Al in real sample.
3
+
The interaction stoichiometry between ST and Al is determined via Job plot analysis. Job's
method is employed using a fluorescence intensity at 459 nm as a function of molar fraction of
3
+
3+
Al , and the total concentration of ST and Al ion is located at 100.0 μM. As shown in Fig. S9, a
3+
1
:1 stoichiometric complexation between ST and Al is confirmed. This result is further
confirmed by HR-MS (Fig. S10), in which the peak at m/z 250.0661 (calcd = 250.0660)
3+
+ +
corresponding to [ST + Al -2H ] and the peak at m/z 282.0924 (calcd = 282.0922)
3+
+ +
3+
corresponding to [ST+Al +CH OH-2H ] are clearly observed when 5.0 equiv of Al is added to
3
1
probe ST in methanol. H NMR titration and FT-IR are utilized to understand the nature of
3
+
interaction of sensor ST towards Al . For a more realistic simulation of the binding mode
3+
between ST and Al in water, we select D O as deuterated solvent to conduct the experiments. As
2
1
shown in Fig. 4, the H NMR spectrum of ST contains signals for CH and aryl fragments but we
2
1
cannot find the H signal of hydroxyl group due to the active hydrogen exchange between ST and
3
+
D O. Upon the addition of 1.0 equiv of Al to ST in D O, the hydrogen atoms on the aromatic
2
2
ring all undergo an overall downfield shift as follows: H shifts from 6.62 ppm to 7.04 ppm, H
d
f
shifts from 6.69 ppm to 6.93 ppm, H shifts from 7.31 ppm to 7.67 ppm, and H shifts from 7.37
c
e
ppm to 7.54 ppm. The hydrogen atom of C＝NH shifts from 8.46 ppm to 9.83 ppm, indicating that
the nitrogen atom in Schiff-base moiety probably participate in the fluorescence sensing process.
Considering the strong acidity (δ = 14.52 ppm in d-DMSO) of the phenolic hydroxyl group in ST,
the hydrogen atom of phenolic hydroxyl is easy to leave, which is also agreed with the reported
work.[54-57] Partial hydrogen of CH upfield shifts from 3.77 ppm to 3.58 ppm, indicating that
2
3
+
part of the oxygen atoms (–CH OH) actually involves in the recognition of Al . In the FT-IR
2
3+
spectra of ST and ST-Al complex (Fig. S11), the characteristic absorption peak of C＝N double
7

ACCEPTED MANUSCRIPT
-1
-1
3+
bond at 1636 cm shifts to 1628 cm in the presence of Al , suggesting that C＝N group of ST
3
+
take part in the chelating reaction with Al . According to these results above, the probable
3+
binding modes of ST with Al is proposed as shown in Fig. S12.
In order to achieve more convenient detection, we fabricates a simple test strip that could
3+
detect Al by soaking a filter paper into a water solution of ST (50.0 μM) and dried in air. In the
3
+
detection process, the test paper is immersed in an aqueous solution containing Al with
-1
-1
concentrations varying from 0.002 mg L to 1.0 mg L for several seconds, and then dried in air.
As shown in Fig. 5, distinguishable color changes of the test paper is observed in the presence of
3
+
Al under the 365 nm UV lamp. Consequently, this easy-to-prepare test paper can be utilized to
3
+
roughly assess whether the system is contaminated by Al .
4. Conclusions
In summary, we reported an economical one-step synthesis and characterization of a new
3
+
water-soluble fluorescence chemosensor for the detection of Al in aqueous solution as well as on
3
+
the test paper. The chemosensor displayed a high selectivity for Al with an obvious fluorescence
3
+
3+
3+
3+
turn-on signal and without the disturbance of other cations especially In , Ga , Fe and Cr .
More importantly, the limit of detection is sufficiently low to detect micromolar concentration of
3
+
3+
Al . The interaction model between ST and Al was also measured.
Acknowledgements
The financial support from National Natural Scientific Foundation of China (NNSFC) Project
(21204042), and Fundamental Research Project of Shenzhen (JCYJ20140509172609160,
JCYJ20140902110354246, JCYJ20160520160830116) are gratefully acknowledged.
References
[
1] J. You, J. Kim, T. Park, B. Kim, E. Kim, Highly Fluorescent Conjugated Polyelectrolyte
Nanostructures: Synthesis, Self‐Assembly, and Al3+ Ion Sensing, Adv. Funct. Mater., 22 (2012)
417-1424.
2] H.N. Kim, W.X. Ren, J.S. Kim, J. Yoon, Fluorescent and colorimetric sensors for detection of lead,
cadmium, and mercury ions, Chem. Soc. Rev., 41 (2012) 3210-3244.
3] C. Han, T. Huang, Q. Liu, H. Xu, Y. Zhuang, J. Li, J. Hu, A. Wang, K. Xu, Design and synthesis of
1
[
[
a highly sensitive “Turn-On” fluorescent organic nanoprobe for iron (iii) detection and imaging, J.
Mater. Chem. C, 2 (2014) 9077-9082.
[
4] G. Aragay, J. Pons, A. Merkoçi, Recent trends in macro-, micro-, and nanomaterial-based tools and
strategies for heavy-metal detection, Chem. Rev., 111 (2011) 3433-3458.
8

ACCEPTED MANUSCRIPT
[
5] L. You, D. Zha, E.V. Anslyn, Recent advances in supramolecular analytical chemistry using optical
sensing, Chem. Rev., 115 (2015) 7840-7892.
6] K.P. Carter, A.M. Young, A.E. Palmer, Fluorescent sensors for measuring metal ions in living
systems, Chem. Rev., 114 (2014) 4564-4601.
7] X. Yang, X. Chen, X. Lu, C. Yan, Y. Xu, X. Hang, J. Qu, R. Liu, A highly selective and sensitive
[
[
fluorescent chemosensor for detection of CN-, SO32- and Fe3+ based on aggregation-induced emission,
J. Mater. Chem. C, 4 (2016) 383-390.
[
8] X. Wan, S. Yao, H. Liu, Y. Yao, Selective fluorescence sensing of Hg 2+ and Zn 2+ ions through
dual independent channels based on the site-specific functionalization of mesoporous silica
nanoparticles, J. Mater. Chem. A, 1 (2013) 10505-10512.
[
9] P. Singh, H. Singh, G. Bhargava, S. Kumar, Triple-signaling mechanisms-based three-in-one
multi-channel chemosensor for discriminating Cu 2+, acetate and ion pair mimicking AND, NOR, INH
and IMP logic functions, J. Mater. Chem. C, 3 (2015) 5524-5532.
[
10] J. Jun Lee, G. Jin Park, Y. Sung Kim, S. Young Lee, H. Ji Lee, I. Noh, C. Kim, A water-soluble
carboxylic-functionalized chemosensor for detecting Al3+ in aqueous media and living cells:
Experimental and theoretical studies, Biosens. Bioelectron., 69 (2015) 226-229.
[
11] S. Kim, J.Y. Noh, K.Y. Kim, J.H. Kim, H.K. Kang, S.-W. Nam, S.H. Kim, S. Park, C. Kim, J. Kim,
Salicylimine-based fluorescent chemosensor for aluminum ions and application to bioimaging, Inorg.
Chem., 51 (2012) 3597-3602.
[
12] D.K. Singha, P. Mahata, Highly Selective and Sensitive Luminescence Turn-On-Based Sensing of
Al3+ Ions in Aqueous Medium Using a MOF with Free Functional Sites, Inorg. Chem., 54 (2015)
373-6379.
13] V.P. Singh, K. Tiwari, M. Mishra, N. Srivastava, S. Saha, 5-[{(2-Hydroxynaphthalen-1-yl)
6
[
methylene} amino] pyrmidine-2, 4 (1H, 3H)-dione as Al 3+ selective colorimetric and fluorescent
chemosensor, Sensor Actuat B-Chem, 182 (2013) 546-554.
[
14] X. Li, M. Yu, F. Yang, X. Liu, L. Wei, Z. Li, A dual-model and on–off fluorescent Al 3+/Cu
+-chemosensor and the detection of F−/Al 3+ with „in situ‟prepared Al 3+/Cu 2+ complexes, New J.
Chem., 37 (2013) 2257-2260.
15] P. Torawane, K. Tayade, S. Bothra, S.K. Sahoo, N. Singh, A. Borse, A. Kuwar, A highly selective
2
[
and sensitive fluorescent „turn-on‟ chemosensor for Al3+ based on CN isomerisation mechanism with
nanomolar detection, Sensor Actuat B-Chem, 222 (2016) 562-566.
[
16] L.K. Kumawat, N. Mergu, M. Asif, V.K. Gupta, Novel synthesized antipyrine derivative based
Naked eye” colorimetric chemosensors for Al3+ and Cr3+, Sensor Actuat B-Chem, 231 (2016)
47-859.
17] S. Goswami, S. Paul, A. Manna, A differentially selective chemosensor for a ratiometric response
to Zn2+ and Al3+ in aqueous media with applications for molecular switches, RSC Adv., 3 (2013)
5079.
18] S. Goswami, A.K. Das, K. Aich, A. Manna, H.-K. Fun, C.K. Quah, Single sensor for multiple
“
8
[
2
[
analytes: fluorogenic detection of Al3+ in aqueous media and AcO− in organic media, Supramol.
Chem., 26 (2014) 94-104.
[
19] G.J. Park, H.Y. Jo, K.Y. Ryu, C. Kim, A new coumarin-based chromogenic chemosensor for the
detection of dual analytes Al3+ and F, RSC Adv., 4 (2014) 63882-63890.
20] H. Liu, X. Hao, C. Duan, H. Yang, Y. Lv, H. Xu, H. Wang, F. Huang, D. Xiao, Z. Tian, Al
[
3
+-induced far-red fluorescence enhancement of conjugated polymer nanoparticles and its application
9

ACCEPTED MANUSCRIPT
in live cell imaging, Nanoscale, 5 (2013) 9340-9347.
21] S. Goswami, A. Manna, S. Paul, K. Aich, A.K. Das, S. Chakraborty, Dual channel selective
[
fluorescence detection of Al(iii) and PPi in aqueous media with an 'off-on-off' switch which mimics
molecular logic gates (INHIBIT and EXOR gates), Dalton T., 42 (2013) 8078-8085.
[
22] S. Goswami, S. Paul, A. Manna, Selective "naked eye" detection of Al(iii) and PPi in aqueous
media on a rhodamine-isatin hybrid moiety, RSC Adv., 3 (2013) 10639-10643.
[
23] S. Goswami, A. Manna, S. Paul, A.K. Maity, P. Saha, C.K. Quah, H.-K. Fun, FRET based
„red-switch‟ for Al3+over ESIPT based „green-switch‟ for Zn2+: dual channel detection with live-cell
imaging on a dyad platform, RSC Adv., 4 (2014) 34572.
24] A. Helal, S.H. Kim, H.-S. Kim, A highly selective fluorescent turn-on probe for Al3+ via
Al3+-promoted hydrolysis of ester, Tetrahedron, 69 (2013) 6095-6099.
25] A. Helal, H.G. Kim, M.K. Ghosh, C.-H. Choi, S.-H. Kim, H.-S. Kim, New regioisomeric
naphthol–thiazole based „turn-on‟ fluorescent chemosensor for Al3+, Tetrahedron, 69 (2013)
600-9608.
26] S.A. Lee, G.R. You, Y.W. Choi, H.Y. Jo, A.R. Kim, I. Noh, S.-J. Kim, Y. Kim, C. Kim, A new
[
[
9
[
multifunctional Schiff base as a fluorescence sensor for Al3+ and a colorimetric sensor for CN- in
aqueous media: an application to bioimaging, Dalton T., 43 (2014) 6650-6659.
[
27] T. Liu, Y. Dong, X. Wan, W. Li, Y. Yao, An easy and accessible water-soluble sensor for the
distinctive fluorescence detection of Zn2+ and Al3+ ions, RSC Adv., 5 (2015) 76939-76942.
28] Y. Lu, S. Huang, Y. Liu, S. He, L. Zhao, X. Zeng, Highly selective and sensitive fluorescent
turn-on chemosensor for Al3+ based on a novel photoinduced electron transfer approach, Org. Lett., 13
[
(
[
2011) 5274-5277.
29] X. Wan, H. Liu, S. Yao, T. Liu, Y. Yao, A stimuli-responsive nanogel-based sensitive and selective
fluorescent sensor for Cr(3+) with thermo-induced tunable detection sensitivity, Macromol. Rapid
Commun., 35 (2014) 323-329.
[
30] Z.-C. Liao, Z.-Y. Yang, Y. Li, B.-D. Wang, Q.-X. Zhou, A simple structure fluorescent
chemosensor for high selectivity and sensitivity of aluminum ions, Dyes and Pigments, 97 (2013)
24-128.
31] C. Liu, Z. Yang, M. Yan, A highly selective and sensitive fluorescent turn-on chemosensor for
Al3+ based on a chromone Schiff base, J. Coord. Chem., 65 (2012) 3845-3850.
32] S. Gui, Y. Huang, F. Hu, Y. Jin, G. Zhang, L. Yan, D. Zhang, R. Zhao, Fluorescence Turn-On
1
[
[
Chemosensor for Highly Selective and Sensitive Detection and Bioimaging of Al3+ in Living Cells
Based on Ion-Induced Aggregation, Anal. Chem., 87 (2015) 1470-1474.
[
(
33] J. Wang, Y. Li, N.G. Patel, G. Zhang, D. Zhou, Y. Pang, A single molecular probe for multi-analyte
Cr 3+, Al 3+ and Fe 3+) detection in aqueous medium and its biological application, Chem. Commun.,
5
0 (2014) 12258-12261.
34] X. Wan, T. Liu, H. Liu, L. Gu, Y. Yao, Cascade OFF-ON-OFF fluorescent probe: dual detection of
trivalent ions and phosphate ions, RSC Adv., 4 (2014) 29479-29484.
35] K. Upadhyay, A. Kumar, Pyrimidine based highly sensitive fluorescent receptor for Al3+ showing
dual signalling mechanism, Org. Biomol. Chem., 8 (2010) 4892-4897.
36] W.-H. Ding, W. Cao, X.-J. Zheng, D.-C. Fang, W.-T. Wong, L.-P. Jin, A highly selective
fluorescent chemosensor for AlIII ion and fluorescent species formed in the solution, Inorg. Chem., 52
[
[
[
(
[
2013) 7320-7322.
37] I.H. Hwang, Y.W. Choi, K.B. Kim, G.J. Park, J.J. Lee, L. Nguyen, I. Noh, C. Kim, A highly
10

ACCEPTED MANUSCRIPT
selective and sensitive fluorescent turn-on Al3+ chemosensor in aqueous media and living cells:
experimental and theoretical studies, New J. Chem., 40 (2016) 171-178.
[
38] Y.S. Kim, J.J. Lee, Y.W. Choi, G.R. You, L. Nguyen, I. Noh, C. Kim, Simultaneous bioimaging
recognition of cation Al3+ and anion F− by a fluorogenic method, Dyes and Pigments, 129 (2016)
3-53.
39] H. Liu, B. Zhang, C. Tan, F. Liu, J. Cao, Y. Tan, Y. Jiang, Simultaneous bioimaging recognition of
4
[
Al 3+ and Cu 2+ in living-cell, and further detection of F− and S 2− by a simple fluorogenic
benzimidazole-based chemosensor, Talanta, 161 (2016) 309-319.
[
40] H. Liu, Y. Dong, B. Zhang, F. Liu, C. Tan, Y. Tan, Y. Jiang, An efficient quinoline-based
fluorescence sensor for zinc (II) and its application in live-cell imaging, Sensor Actuat B-Chem, 234
(
[
2016) 616-624.
41] J. Kumar, M.J. Sarma, P. Phukan, D.K. Das, A new simple Schiff base fluorescence “on” sensor
for Al 3+ and its living cell imaging, Dalton T., 44 (2015) 4576-4581.
42] V.C. da Silveira, J.S. Luz, C.C. Oliveira, I. Graziani, M.R. Ciriolo, A.M.d.C. Ferreira,
[
Double-strand DNA cleavage induced by oxindole-Schiff base copper(II) complexes with potential
antitumor activity, J. Inorg. Biochem., 102 (2008) 1090-1103.
[
43] Y. Li, Z.-y. Yang, DNA binding affinity and antioxidative activity of copper(II) and zinc(II)
complexes with a novel hesperetin Schiff base ligand, Inorg. Chim. Acta, 362 (2009) 4823-4831.
44] G. Chen, L. Gu, Y. Yao, A novel zinc-containing additive for the long-term thermal stabilization of
poly (vinyl chloride), Polym. Degrad. Stab., 107 (2014) 113-119.
45] M. Zhang, Y. Yang, L. Liu, W. Chang, J. Li, Pseudo-Cryptand-Containing Copolymers:
[
[
Cyclopolymerization and Biocompatible Water-Soluble Al3+ Fluorescent Sensor in Vitro,
Macromolecules, (2016).
[
46] L. Zhi, J. Liu, Y. Wang, W. Zhang, B. Wang, Z. Xu, Z. Yang, X. Huo, G. Li, Multifunctional Fe 3
O 4 nanoparticles for highly sensitive detection and removal of Al (iii) in aqueous solution, Nanoscale,
(2013) 1552-1556.
47] T. Li, R. Fang, B. Wang, Y. Shao, J. Liu, S. Zhang, Z. Yang, A simple coumarin as a turn-on
fluorescence sensor for Al (III) ions, Dalton T., 43 (2014) 2741-2743.
48] C. Kim, J.-Y. Hwang, K.-S. Ku, S. Angupillai, Y.-A. Son, A renovation of non-aqueous Al3+
5
[
[
sensor to aqueous media sensor by simple recyclable immobilize electrospun nano-fibers and its uses
for live sample analysis, Sensor Actuat B-Chem, 228 (2016) 259-269.
[
49] A. Sahana, A. Banerjee, S. Das, S. Lohar, D. Karak, B. Sarkar, S.K. Mukhopadhyay, A.K.
Mukherjee, D. Das, A naphthalene-based Al 3+ selective fluorescent sensor for living cell imaging, Org.
Biomol. Chem., 9 (2011) 5523-5529.
[
50] M. Shellaiah, Y.-H. Wu, A. Singh, M.V. Ramakrishnam Raju, H.-C. Lin, Novel pyrene- and
anthracene-based Schiff base derivatives as Cu2+ and Fe3+ fluorescence turn-on sensors and for
aggregation induced emissions, J. Mater. Chem. A, 1 (2013) 1310-1318.
[
51] A. Gogoi, S. Samanta, G. Das, A benzothiazole containing CHEF based fluorescence turn-ON
sensor for Zn2+ and Cd2+ and subsequent sensing of H2PO4− and P4O74− in physiological pH,
Sensor Actuat B-Chem, 202 (2014) 788-794.
[
52] R. Zhang, C.-J. Zhang, Z. Song, J. Liang, R.T.K. Kwok, B.Z. Tang, B. Liu, AIEgens for real-time
naked-eye sensing of hydrazine in solution and on a paper substrate: structure-dependent signal output
and selectivity, J. Mater. Chem. C, (2016).
[
53] V. Lakshmi, M. Ravikanth, Boron-dipyrromethene based multi-anionic sensor and a specific
11

ACCEPTED MANUSCRIPT
cationic sensor for Fe 3+, J. Mater. Chem. C, 2 (2014) 5576-5586.
54] S.M. Lee, K.S. Sim, K.M. Lo, Synthesis, characterization and biological studies of diorganotin (IV)
complexes with tris [(hydroxymethyl) aminomethane] Schiff bases, Inorg. Chim. Acta, 429 (2015)
95-208.
55] Y. Sui, X. Zeng, X. Fang, X. Fu, Y.a. Xiao, L. Chen, M. Li, S. Cheng, Syntheses, structure, redox
[
1
[
and catalytic epoxidation properties of dioxomolybdenum (VI) complexes with Schiff base ligands
derived from tris (hydroxymethyl) amino methane, J. Mol. Catal. A: Chem., 270 (2007) 61-67.
[
56] M. Dey, C.P. Rao, P. Saarenketo, K. Rissanen, E. Kolehmainen, Four‐, Five‐and Six‐
Coordinated ZnII Complexes of OH‐Containing Ligands: Syntheses, Structure and Reactivity, Eur. J.
Inorg. Chem., 2002 (2002) 2207-2215.
[
57] C.P. Raptopoulou, Y. Sanakis, V. Psycharis, M. Pissas, Zig-zag [MnIII4] clusters from polydentate
Schiff base ligands, Polyhedron, 64 (2013) 181-188.
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Captions
Scheme 1 Schematic illustration of the synthesis of fluorescent chemosensor ST.
Fig .1 Fluorescence spectra of ST (50.0 μM) in Tris buffer (10.0 mM, pH = 7.0) in the absence
and presence of 250.0 μM of various metal ions, λ =310 nm. Inset: Optical photographs (UV 365
ex
nm).
3
+
Fig. 2 Fluorescence spectra of ST (50.0 μM) in the presence of increasing concentrations of Al
in Tris buffer (10.0 mM, pH = 7.0). Inset: fluorescence intensity at 459 nm as a function of
3
+
[
Al ]/[ST], λ =310 nm.
ex
Fig. 3 Fluorescence intensity at 459 nm of ST (50.0 μM) in the presence of selected metal ions
250.0 μM) in Tris buffer solution (10.0 mM, pH = 7.0). The black bars (left) represent the
intensity of ST in the presence of selected cations; the red bars (right) represent the intensity upon
(
3+
an addition of Al (250.0 μM) to a solution.
1
3+
Fig. 4 H NMR spectra of ST in D O alone and in the presence of Al .
2
Fig. 5 Optical photographs (UV 365 nm) obtained for probe ST (50.0 µM) coated test strips before
3
+
and after the exposure to aqueous solution containing different concentrations of Al .
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Scheme 1
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Figure 1
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Figure 2
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Figure 3
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Figure 4
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Figure 5
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Graphical abstract
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Highlights:
1
2
3
.
.
.
The sensor was synthesized in one-step procedure and yield was 85%.
Detection process was conducted in 100% aqueous solution.
3
+
3+
No disturbances from typical competitive ions such as Fe , Cr were founded in the
detection process.
3+
-7
4
5
.
.
Detection limit for Al is 3.2 × 10 M.
3+
Detection for Al in aqueous solution and on paper substrate was evaluated.
21