A "turn-on" fluorescent chemosensor for aluminum ion and cell imaging application

Article abstract of DOI:10.1016/j.saa.2015.09.009

A simple and efficient fluorescent chemosensor for Al^{3 +} is reported in the paper. The chemosensor is obtained by dehydration reaction of 2-hydroxy-1-naphthaldehyde and 2-aminophenol. The chemosensor has high selectivity and sensitivity for Al^{3 +} and displays fluorescence "off-on" switch signal. The detection limit of the chemosensor for Al^{3 +} can reach 1.0 × 10^{- 7} M in DMSO/H₂O (1:9, v/v) solution. The mass spectra and Job's plot analysis confirm the 1:1 stoichiometry between chemosensor and Al^{3 +}. Potential utilization of the probe as an intracellular sensor of Al^{3 +} in human cancer (HiSa) cells is also examined by confocal fluorescence microscopy.

Full text of DOI:10.1016/j.saa.2015.09.009

A “turn-on” fluorescent chemosensor for aluminum ion and cell imaging
application
Ailing Guo, Ruitao Zhu, Yuehong Ren, Jinlong Dong, Liheng Feng
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DOI:
Reference:
S1386-1425(15)30224-9
doi: 10.1016/j.saa.2015.09.009
SAA 14073
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3 July 2015
2 September 2015
20 September 2015
Please cite this article as: Ailing Guo, Ruitao Zhu, Yuehong Ren, Jinlong Dong, Liheng
Feng, A “turn-on” fluorescent chemosensor for aluminum ion and cell imaging applica-
tion, (2015), doi: 10.1016/j.saa.2015.09.009
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ACCEPTED MANUSCRIPT
A “turn-on” fluorescent chemosensor for aluminum ion and
cell imaging application
Ailing Guoa, Ruitao Zhub*, Yuehong Renb, Jinlong Dongb, Liheng Fengc*
aSchool of Chinese Materia Medica, Shanxi University of Traditional Chinese Medicine, Taiyuan
030024, PR China;
bDepartment of Chemistry, Taiyuan Normal University, Taiyuan 030031, PR China;
cSchool of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China
Corresponding author E-mail: (R.T. Zhu) ruitaozhu@126.com, (L.H. Feng) lhfeng@sxu.edu.cn
Tel: (86)351-7017904, Fax: (86)351-7011688
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Abstract
A simple and efficient fluorescent chemosensor for Al3+ is reported in the paper.
The chemosensor is obtained by dehydration reaction of 2-hydroxy-1-naphthaldehyde
and 2-aminophenol. The chemosensor has high selectivity and sensitivity for Al3+ and
displays fluorescence “off-on” switch signal. The detection limit of the chemosensor
for Al3+ can reach 1.0×10−7 M in DMSO/H2O (1:9, v/v) solution. The mass spectra and
Job’s plot analysis confirm the 1:1 stoichiometry between chemosensor and Al3+.
Potential utilization of the probe as an intracellular sensor of Al3+ in human cancer
(HiSa) cells is also examined by confocal fluorescence microscopy.
Keywords: Fluorescence, Chemosensor, Aluminum ion, Naphthalene, Cells imaging
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1. Introduction
Aluminum is the third most prevalent (8.3% by weight) metallic element in the
earth. It has been widely used in packing materials, clinical drugs, food additives and
water purification et al [1-4]. The excess of aluminum can cause many health hazards
such as Alzheimer’s disease [5,6], Parkinson’s disease [7], Osteomalacia [8], and even
to the risk of cancer of the breast [9]. Additionally, the World Health Organization
(WHO) prescribed the average daily human intake of aluminum as around 3-10 mg
with a weekly tolerable dietary intake of 7 mg·kg-1 body weight. The WHO has listed
Aluminum as a source of food pollution and limited its drinking water concentration
to 7.41 mM [10]. Therefore, it is necessary and highly desirable to develop some
analytical methods for detecting and controlling the concentration levels of aluminum
in the environmental and biological systems.
In the past ten years, several methods used for quantification of aluminum ion are
atomic absorption spectrometry (AAS) [11,12], inductively coupled plasma mass
spectroscopy (ICPMS) [13], inductively coupled plasma atomic emission
spectrometry (ICP-AES) [14], electrochemical method [15,16] and fluorescent
chemosensors. Compared with other methods, the fluorescence method can provide a
simple and cost-effective detection way together with high sensitivity, good selectivity,
short response time, real-time monitoring [17,18]. However, the poor coordination
ability of aluminum ion makes it develop slowly. It is because, as a hard acid,
aluminum ion prefers to coordinate with hard base such as N and O atoms. Schiff
bases (imine) are well known to be good ligands for metal ions [19,20]. Several
publications have demonstrated that Schiff bases with proper placement of additional
N or O as donor atoms can form stable complexes with transition metal ions and have
been used as the ionophore in optical sensors for determining various cations [21-23].
Herein, we designed and prepared a simple chemosensor 1-{[(2-hydroxyphenyl)-
imino]methyl}naphthalen-2-ol (HPIN) with Schiff-base unit and naphthalene group.
Based on photoinduced electron transfer (PET) mechanism, the weak fluorescence of
HPIN happens obvious enhancement with the addition of only Al3+. The mass spectra
and Job’s plot titration curve are be used to study the bonding ratio of HPIN and Al3+.
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In order to develop potential utilization of HPIN, as intracellular sensors, the
interaction of HPIN with Al3+ in human cancer (HiSa) cells is examined by confocal
fluorescence microscopy.
2. Experimental
2.1. Materials and instruments
All chemicals were obtained from commercial suppliers and used without further
purification. 1H NMR spectra were recorded on Bruker 300 MHz spectrometers, the
chemical shifts (δ) were reported as ppm in DMSO-d6. IR spectra were recorded with
a ThermoFisher Nicolet iS5 FT-IR spectrophotometer as KBr pellets with absorption
reported in cm-1. Elemental analyses were measured on a EuroVector EA3000
elemental analyzer. ESI-MS spectra were recorded on an Agilent 6520 Accurate-Mass
Q-TOF LC/MS mass spectrometer. UV-visible (UV-Vis) spectra were measured with
a Varian 50 BIO spectrophotometer. Fluorescence spectra were recorded on an F-4600
fluorescence spectrophotometer equipped with quartz cuvettes of 1 cm path length at
room temperature. Both the excitation and emission slit widths were 5.0 nm.
2.2 UV-vis and fluorescence spectra studies
Stock solutions of various metal ions (1.0 mM) were prepared using nitrate salts.
A stock solution of HPIN (1.0 mM) in DMSO was prepared. Double-distilled water
was used throughout the experiments. The working solution of HPIN was then diluted
to 1.0 μM in DMSO/H2O (1:9, v/v) solution. In fluorescence titration experiments,
each time a 2 mL solution of L (1.0 μM) was filled in a quartz optical cell of 1 cm
optical path length, and the ions stock solution were added into the quartz optical cell
gradually by using a pipette. The binding constants were obtained from the emission
intensity data following the modified Benesi-Hildebrand equation [24] (A):
1
1
1


F  Fmin K(Fmax  Fmin )[Al3 ] Fmax  Fmin
where Fmin, F, and Fmax are the emission intensities of the organic moiety considered in
the absence of aluminum ion, at an intermediate aluminum concentration, and at a
concentration of complete interaction, respectively, and where K is the binding
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constant.
2.3 Preparation of HPIN and HPIN/Al3+ complex [25,26]
The fluorescent chemosensor 1-{[(2-hydroxyphenyl)imino]methyl}naphthalen-
2-ol (HPIN) was designed and synthesized in one step as shown in Scheme 1.
2-Hydroxy-1-naphthaldehyde (1.72g, 10.0 mmol) in 50 ml absolute ethanol was
added drop wise into a solution of 2-aminophenol (1.09 g, 10.0 mmol) in 50 ml
absolute ethanol under stirring. And then, the reaction mixture was further stirred for
4 h at room temperature until an orange-yellow precipitate appeared. The resulting
precipitate was filtered and washed 2 times with ice ethanol. The solid obtained was
recrystallized from ethanol to give orange-yellow crystals. Yield: 85%, m.p.:
252-253 °C. Anal. Calc. for C17H13NO2: C, 77.55; H, 4.98; N, 5.32. Found: C, 78.27;
H, 5.02; N, 5.09. IR (KBr pellet, cm-1): 3427 (OH), 1632 (C=N); 1H NMR (DMSO-d6,
δH, ppm): 10.32 (s, 1H), 9.51 (d, 1 H), 8.40 (d, 1 H), 7.95 (d, 1 H), 7.82 (d, 1 H), 7.69
(d, 1 H), 7.51 (t, 1 H), 7.29 (t, 1 H), 7.11 (d, 1 H), 7.01 (m, 2H), 6.79 (d, 1 H).
ESI-MS (m/z): [M+H]+= 264.1018.
A mixture of HPIN (0.26 g, 1.0 mmol) and Al(NO3)3·9H2O ( 0.38 g, 1.0 mmol) in
10 mL of methanol was stirred and refluxed for 5 h. The reaction mixture was
concentrated by rotary evaporation and cooled to precipitate solid. The solid was
collected on a Buchner funnel, washed thoroughly with methanol and dried at ambient
temperature to obtain yellow brown solid. Yield 68%. IR (KBr pellet, cm-1): 3423
(OH), 1621 (C=N), 1384 (NO3). ESI-MS (m/z): [(M-2H)+Al( Ⅲ )]+=288.0584,
[(M-2H)+Al(Ⅲ)+H2O]+=306.0701, [(M-2H)+Al(Ⅲ)+CH3OH]+=320.0859, [(M-2H)+
Al( Ⅲ )+H2O+Na]+=329.0862, [(M-2H)+Al( Ⅲ )+2H2O+Na]+=347.0969, [(M-2H)+
Al(Ⅲ)+H2O+CH3OH+Na]+=361.1125, [(M-2H)+Al(Ⅲ)+H2O+NO3+2]+=370.1126.
2.4 Cells culture and imaging
Under a humid atmosphere containing 5% CO2, SiHa cells were grown in DMEM
medium containing 10% FBS routinely, then harvested for subculture using trypsin
(0.05%, Gibco/Invitrogen) at 37 °C. SiHa cells were incubated onto a 35 mm ×35 mm
Petri dish with a glass bottom, then allowed to grow for 24 h for attachment, after
which 1 mL of DMEM medium containing 10% 5 µM compound HPIN was used to
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incubated the SiHa cells at 37 ºC for 5 h. The medium was replaced and
phosphate-buffered saline (PBS, pH =7.4) was used to wash the cells thrice. And two
equivalent metal ion in PBS buffer solution were added into the dish and the cells
were cultured at 37 ºC for 1 h. The medium was replaced and phosphate-buffered
saline (PBS, pH =7.4) was used to wash the cells thrice. Then fresh medium with
cytoplasm located dye (Lyso tracker red) was added and incubated. After washing
thrice with PBS, the images of the cells were recorded on confocal laser scanning
microscopy.
3. Results and discussion
3.1 UV-Vis absorption and fluorescence emission spectra of HPIN with Al3+
Firstly, the interaction of HPIN with Al3+ was investigated by UV-Vis absorption
spectrum. Fig.S1 shows the change of the UV-vis spectrum of HPIN with addition of
Al3+ in DMSO/H2O (1:9, v/v) solution. As can be seen from Fig.S1, Upon the
addition of Al3+, the absorption intensities of HPIN peaks about 450 nm (n-π*
transition from imine) and 310 nm (π-π* transition from naphthalene) all gradual
decrease with the solution color from blue to yellow under 365 nm irradiation
(Scheme 1). Next, the fluorescence response behavior of HPIN with Al3+ was also
examined in DMSO/H2O (1:9, v/v) solution. As shown in Fig.1, the HPIN almost not
shows fluorescence peak at 524 nm when it is excited at 440 nm in DMSO/H2O (1:9,
v/v) solution. However, upon the addition of Al3+, the fluorescence intensity of HPIN
at 524 nm shows a significant fluorescence enhancement. The fact displays that HPIN
is a “turn-on” fluorescence probe for Al3+ and 20-fold enhancement of fluorescence
intensity at 524 nm can obtain only at Al3+/HPIN (1/1) condition. Based on the
fluorescence titration, the binding constant of HPIN for Al3+ has been estimated using
the Benesi-Hildebrand equation (A). The stability constant is determined as 2.2×104,
that is within the range 103-109 of those reported for Al3+-binding sensors [27-29].
To reflect the high sensitivity, the detection limit was evaluated by using the
method of gradually decreasing concentration of Al3+. When the concentration of Al3+
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decreases to 0.1μM，an observable stripping peak was observed. When further
decreasing the concentration, the stripping peak almost disappears. So, the detection
limit is evaluated to be 1.0×10-7 M, which enables to meet the detection of Al3+ in
many chemical and biological systems [30,31]. Noticeable, it is a good linear relation
for relative intensities of HPIN to Al3+ concentrations (Fig.2).
3.2 The binding mode and action mechanism of HPIN with Al3+
To explore the binding mode between HPIN and Al3+ complex, binding analysis
was carried out by the Job’s plot method (Fig.3). The total concentration of HPIN and
Al3+ was 1.0 μM in the experimental process and the concentration of HPIN and Al3+
changed correspondingly. As can be seen from Fig.3, the maximum mole fraction of
HPIN to Al3+ is 0.5, which established a 1:1 binding stoichiometry of HPIN to Al3+.
The 1:1 coordination stoichiometry was further confirmed from ESI-MS spectra,
where some peaks at m/z 288.0584 with 7% abundance, assignable to [(M-2H)+
Al(Ⅲ)]+ , [(M-2H)+ Al(Ⅲ) + H2O]+, m/z, 306.0701 (observed with 3% abundance)
and [(M-2H)+ Al(Ⅲ) + CH3OH]+, m/z, 320.0859, (observed with 30% abundance
288.0584 ([HPIN-2H+Al]+) were clearly observed (Fig.S2 and S3). Additionally,
Compared the IR spectra of the complex with HPIN (Fig.S4 and S5), we can see two
differences: (i) the stretch vibration of imine group (C=N) at 1632 cm-1, which was a
strong and sharp absorption band, changed to 1621 cm-1, a mild and broad band; (ii)
The new intense absorption band at 1384 cm-1 corresponding to the NO3 stretching
vibration appeared. These differences suggest that the imine groups and NO3 group
took part in the coordination with Al3+. From these data, it may be deduced that the
possible coordination modes of HPIN/Al3+ complex is 1:1 binding stoichiometry.
Based on the above results, the supposed action mechanism of HPIN with Al3+ is
listed in Scheme 1. Due to the photoinduced electron transfer from the nonbonding
electron pair from nitrogen atom to the fluorophore (naphthyl ring), the fluorescence
of HPIN is restrained. So, the fluorescence of HPIN is “off” state. When introducing
Al3+ to HPIN probe, the restrained fluorescence of HPIN is released owing to the
binding of Al3+ with nitrogen and oxygen atoms, which will destroy the PET process
in HPIN [32-36]. In the fact, the fluorescence of HPIN is “on” state with the addition
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of Al3+. In other word, HPIN can be used to determine Al3+ with fluorescence “off-on”
response.
3.3 Selectivity of HPIN probe for Al3+
For a chemosensor, the selectivity for analytes is one of the most important
parameters. Hence, the interactions of HPIN with other metal ions were studied by
fluorescence technique. From Fig.4, the fluorescence intensity of HPIN takes place a
significant enhancement with only addition of Al3+ in many metal ions (Na+, K+, Ca2+,
Al3+, Mg2+, Mn2+, Zn2+, Co2+, Pb2+, Cu2+, Cd2+, Ni2+, Ag+, Fe3+, Cr3+, Ba2+, Bi3+, Hg2+,
Sr2+, Ga3+, In3+). And, compared with other metal ions, the relative intensity of HPIN
(1.010-6 mol/L) can reach 19-fold enhancement in one equiv. Al3+ (1.010-6 mol/L,
Fig.S6), which displays HPIN has a high selectivity for Al3+.
In view of interference factors in practical applicability, the fluorescence
competitive experiments of HPIN/Al3+ with other various metal ions were also
investigated, respectively (Fig.5). As can be seen from Fig.5, the fluorescence
emission intensity of HPIN/Al3+ solution containing other metal ions (Na+, K+, Ca2+,
Mg2+, Mn2+, Zn2+, Co2+, Pb2+, Cu2+, Cd2+, Ni2+, Ag+, Fe3+, Cr3+, Ba2+, Bi3+, Hg2+, Sr2+,
Ga3+, In3+) did not show significant variation by comparison with the fluorescence
intensity of HPIN/Al3+ solution, respectively. These results suggest that HPIN may be
used for the selective detection of Al3+ ion in practical sample with a little
interference.
3.4 Cell Imaging in Vitro
Biological application of HPIN to detect Al3+ was investigated by confocal laser
scanning microscope (CLSM). Firstly, the SiHa cells were cultured with compound
HPIN at 37 °C for 5 h, and then, the two equivalent Al3+ were added the system and
sequentially cultured the cells for 1 h. The fluorescence imaging was taken, where
Lyso tracker red was used as a cytoplasm located dye. As shown in Fig.6, the
cytoplasm regions of SiHa cells are stained by HPIN/Al3+ and well overlay with
cytoplasm located dye (Lyso tracker red). Obviously, the cells can be illumed by
introducing Al3+ to SiHa cells with HPIN. Based on control experiments, we can
obtain a fact that HPIN can be used to detect and tract Al3+ in intracellular with
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“off-on” fluorescence signal.
4. Conclusion
In summary, a simple and facile chemosensor HPIN for Al3+ with fluorescence
“off-on” signal was obtained. The chemosensor displays high selectivity and
sensitivity for Al3+ in DMSO/H2O (v/v=1/9). Based on these experimental data, the
work has the following features: (1) the fluorescence receptor is simple and easily
prepared; (2) the receptor HPIN has higher sensitivity and selectivity for Al3+ and may
be used to determine Al3+; (3) it is a fluorescence “off-on” probe; (4) the detection of
HPIN for Al3+ may be realized in biological system. In view of above points, the work
not only obtains a facile chemosensor for Al3+, but also provides a new strategy for
designing simple fluorescence receptors for metal ions recognition.
Acknowledgements
The work described in this paper was supported by the National Nature Science
Foundation (No.21371110 and 21201024), the Youth Science Foundation of Shanxi
Province (No.2014021006), the Natural Science Foundation of Shanxi province (No.
2015011107), the Program for the Outstanding Innovative Teams of Higher Learning
Institutions of Shanxi (2013070803) and the Patent Promotion Program of Shanxi
Province (No.141006).
Appendix. Supplementary data
Other fluorescence spectroscopy (PDF) and characteristic data associated with this
article can be found in the online version, at doi:
References
[1] M.G. Soni, S.M. White, W.G. Flamm, G.A. Burdock, Safety evaluation of dietary
aluminum, Regul. Toxicol. Pharmacol. 33 (2001) 66-79.
9

ACCEPTED MANUSCRIPT
[2] R. Azadbakht, T. Almasi, H. Keypour, M. Rezaeivala, A new asymmetric Schiff
base system as fluorescent chemosensor for Al3+ ion, Inorg. Chem. Commun. 33
(2013) 63-67.
[3] Z.C. Liu, Z.Y. Yang, Y.X. Li, T.R. Li, B.D. Wang, Y. Li, X.L. Jin, An effective
mutli-wavelength emissive aluminum ion fluorescence chemosensor based on
3-[1′-(2′-hydroxy-α-methylbenzylidene-imino)]-2-(p-N,N-dimethylaminophenyl)-
1,2-dihydroquinazolin-4-(3H)-one, Inorganica Chimica Acta. 395 (2013) 77-80.
[4] A.J. Blotcky, D. Hobson, J.A. Leffler, E.P. Rack, R.R. Recker, Determination of
trace aluminum in urine by neutron activation analysis, Anal. Chem. 48 (1976)
1084-1088.
[5] T.P. Flaten, Aluminium as a risk factor in Alzheimer’s disease, with emphasis on
drinking water. Brain Res. Bull. 55 (2001) 187-196.
[6] D. P. Perl, A. R. Brody, Alzheimer’s disease: X-Ray spectrometric evidence of
aluminum accumulation in neurofibray tangle-bearing neurons, Science 208 (1980)
297-299.
[7] D. P. Perl, D. C. Gajdusek, R. M. Garruto, R. T. Yanagihara, C. J. Gibbs,
Intraneuronal aluminum accumulation in amyotrophic lateral sclerosis and
Parkinsonism-dementia of gauam, Science 217 (1982) 1053-1055.
[8] G.C. Woodson, An interesting case of osteomalacia due to antacid use associated
with stainable bone aluminum in a patient with normal renal function, Bone 22
(1998) 695-698.
[9] P.D. Darbre, Aluminium, antiperspirants and breast cancer, J. Inorg. Biochem. 99
(2005) 1912-1919.
[10] Z. Krejpcio, R.W. Wojciak, The influence of Al3+ ions on pepsin and trypsin
activity in vitro, Polish Journal of Environmental Studies 11 (2002) 251-254.
[11] T.A. Zafar, D. Teegarden, C. Ashendel, M.A. Dunn, C.M. Weaver, Aluminum
negatively impacts calcium utilization and bone in calcium-deficient rats. Nutr.
Res. 24(2004) 243-259.
[12] C. Guo, G.W. Hsu, C. Chuang, P. Chen, Aluminum accumulation induced
testicular oxidative stress and altered selenium metabolism in mice, Environ.
10

ACCEPTED MANUSCRIPT
Toxicol. Phar. 27 (2009) 176-181.
[13] B. Deng, J. Feng, J. Meng, Speciation of inorganic selenium using capillary
electrophoresis– inductively coupled plasma-atomic emission spectrometry with
on-line hydride generation, Anal. Chim. Acta 583 (2007) 92-97.
[14] P. Olmedo, A. Pla, A.F. Hernández, O. López-Guarnido, L. Rodrigo, F. Gil,
Validation of a method to quantify chromium, cadmium, manganese, nickel and
lead in human whole blood, urine, saliva and hair samples by electrothermal
atomic absorption spectrometry, Anal. Chim. Acta 659 (2010) 60-67.
[15] R.S. Maharia, R.K. Dutta, R. Acharya, A. Reddy, Heavy metal bioaccumulation
in selected medicinal plants collected from Khetri copper mines and comparison
with those collected from fertile soil in Haridwar, India, J. Environ. Sci. Health B
45 (2010) 174-181.
[16] S. Kameo, K. Nakai, N. Kurokawa, T. Kanehisa, A. Naganuma, H. Satoh, Metal
components analysis of metallothionein2 III in the brain sections of
metallothionein-I and metallothionein-II null mice exposed to mercury vapor
with HPLC/ICP/MS, Anal. Bioanal. Chem. 381 (2005) 1514.
[17] F. Yu, X. Han, L. Chen, Fluorescent probes for hydrogen sulfide detection and
bioimaging, Chem. Commun. 50 (2014) 12234-12249.
[18] R. Wang, C. Yu, F. Yu, L. Chen, C. Yu, Molecular fluorescent probes for
monitoring pH changes in living cells, TrAC Trends Anal. Chem. 29 (2010)
1004-1013.
[19] Y. Xu, J. Meng, L. Meng, Y. Dong, Y. Cheng, C. Zhu, A highly selective
fluorescence-based polymer sensor incorporating an (R,R)-salen moiety for
Zn2+ detection, Chem. Eur. J. 16 (2010) 12898-12903.
[20] R. Joseph, J.P. Chinta, C.P. Rao, Lower rim 1,3-diderivative of calix[4]arene-
appended salicylidene imine (H2L): experimental and computational studies of
the selective recognition of H2L toward Zn2+ and sensing phosphate and amino
acid by [ZnL], J. Org. Chem. 75 (2010) 3387-3395.
[21] D. Maity, T. Govindaraju, Conformationally constrained (coumarin−triazolyl−
bipyridyl) click fluoroionophore as a selective Al3+ sensor, Inorg. Chem. 49
11

ACCEPTED MANUSCRIPT
(2010) 7229-7231.
[22] D. Maity, T. Govindaraju, Pyrrolidine constrained bipyridyl-dansyl click
fluoroionophore as selective Al3+ sensor, Chem. Commun. (2010) 4499-4501.
[23] R. Azadbakht, J. Khanabadi, A novel aluminum-sensitive fluorescent nano-
chemosensor based on naphthalene macrocyclic derivative, Tetrahedron 69 (2013)
3206-3211.
[24] H.A. Benesi, J.H. Hildebrand, A spectrophotometric investigation of the
interaction of iodine with aromatic hydrocarbons, J. Am. Chem. Soc. 71 (1949)
2703-2707.
[25] D. Sharma, S.K. Sahoo, R.K. Bera, R. Kamal, Spectroscopic and computational
study of a naphthalene derivative as colorimetric and fluorescent sensor for
bioactive anions, J Fluoresc 23 (2013) 387-392.
[26] S. Das, D. Karak, S. Lohar, A. Banerjee, A. Sahana, D. Das, Interaction of a
naphthalene based fluorescent probe with Al3+: experimental and computational
studies, Anal. Methods 4 (2012) 3620-3624.
[27] Y.K. Jang, U.C. Nam, H.L. Kwon, I.H. Hwang, C. Kim, A selective colorimetric
and fluorescent chemosensor based-on naphthol for detection of Al3+ and Cu2+,
Dyes Pigment. 99 (2013) 6-13.
[28] H.M. Park, B.N. Oh, J.H. Kim, W. Qiong, I.H. Hwang, K.D. Jung, Fluorescent
chemosensor based-on naphthol-quinoline for selective detection of aluminum
ions, Tetrahedron Lett. 52 (2011) 5581-5584.
[29] J. Lee, H. Kim, S. Kim, J.Y. Noh, E.J. Song, C. Kim, Fluorescent dye containing
phenol-pyridyl for selective detection of aluminum ions, Dyes Pigm. 96 (2013)
590-594.
[30] L. Mei, Y. Xiang, N. Li, A.J. Tong, A new fluorescent probe of rhodamine B
derivative for the detection of copper ion , Talanta 72 (2007) 1717-1722.
[31] D. Maity, T. Govindaraju, Conformationally constrained (coumarin-triazolyl-
bipyridyl) click fluoroionophore as a selective Al3+ sensor, Inorg. Chem. 49
(2010) 7229-7231.
[32] S. Sinha, R.R. Koner, S. Kumar, J.M. Monisha, P.V. Kazi, S. Ghosh,
12

ACCEPTED MANUSCRIPT
Imine containing benzophenone scaffold as an efficient chemical device to detect
selectively Al3+ , RSC Adv. 3 (2013) 345-351.
[33] S. Kim, J.Y. Noh, K.Y. Kim, J.H. Kim, H.K. Nam, Salicylimine-based
fluorescent chemosensor for aluminum ions and application to bioimaging, Inorg.
Chem. 51 (2012) 3597-3602.
[34] J.F. Zhang, Y. Zhou, J. Yoon, J.S. Kim, Recent progress in fluorescent and
colorimetric chemosensors for detection of precious metal ions (silver, gold
andplatinum ions), Chem. Soc. Rev. 7 (2011) 3416-3429.
[35] A. Ajayaghosh, P. Carol, S. Sreejith, A ratiometric fluorescence probe for
selective visual sensing of Zn2+, J.Am. Chem. Soc. 127 (2005) 14962-14963.
[36] A.P. de Silva, H.Q. Gunaratne, T. Gunnlaugsson, A.J. Huxley, C.P. McCoy, J.T.
Rademacher, T.E. Rice, Signaling recognition events with fluorescent sensors
and switches, Chem. Rev. 97 (1997) 1515-1566.
13

ACCEPTED MANUSCRIPT
Biographies
Guo A. female, Master. School of Chinese Materia Medica, Shanxi University of
Traditional Chinese Medicine, his current research interests are organic function
materials and chemosensor.
Zhu R. male, associate professor, Master. Department of Chemistry, Taiyuan Normal
University. His current research interests are chemosensors and interactions of organic
macromolecules with biological molecules.
Ren Y. male, Professor, Master. Department of Chemistry, Taiyuan Normal University.
His current research interests are bioorganics, sensors and interaction of organic
macromolecules with sugar.
Dong J. male, Master. Department of Chemistry, Taiyuan Normal University. His
current research interests are bioorganics, sensors, macromolecules..
Feng L. male, Professor, PhD. School of chemistry and chemical engineering, Shanxi
University, his current research interests are bioorganics, sensors, macromolecules,
luminescent materials, polymers and interaction of organic macromolecules with
biological species.
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The scheme and figures captions
Scheme 1. The probable bonding model of HPIN with Al3+ and the color change of
HPIN (2.010-5 mol/L) solution by introducing Al3+ (2.010-4 mol/L).
Fig. 1. Fluorescence spectra of HPIN (1.010-6 mol/L) in DMSO/H2O (1:9, v/v)
solution upon the addition of Al3+ (0, 0 mol/L; 1, 1.010-7 mol/L; 2, 2.010-7
mol/L; 3, 3.010-7 mol/L; 4, 4.010-7 mol/L; 5, 5.010-7 mol/L; 6, 6.010-7
mol/L; 7, 7.010-7 mol/L; 8, 8.010-7 mol/L; 9, 9.010-7 mol/L; 10, 1.010-6
mol/L; 11, 1.210-6 mol/L 12, 1.510-6 mol/L, respectively.) with an excitation
of 440 nm.
Fig.2. Characteristic fluorescence response by the introduction of Al3+ to the HPIN
(1.010-6 mol/L) in DMSO/H2O (1:9, v/v) solution. The concentrations of Al3+
are from 1.010-7 to 1.010-6 mol/L.
Fig.3. Job plot of HPIN and Al3+ in DMSO/H2O solution (1:9, v/v). The total
concentration of HPIN and Al3+ is 1.010-6 mol/L.
Fig.4. Fluorescence spectra of HPIN (1.010-6 mol/L) in DMSO/H2O (1:9, v/v)
solution by adding metal ions (1.010-6 mol/L), respectively.
Fig.5. Characteristic fluorescence response of HPIN (1.010-6 mol/L) with Al3+ in the
presence of other metal ions (Na+, K+, Ca2+, Mg2+, Mn2+, Zn2+, Co2+, Pb2+,
Cu2+, Cd2+, Ni2+, Ag+, Fe3+, Cr3+, Ba2+, Bi3+, Hg2+, Sr2+, Ga3+, In3+,
respectively) in DMSO/H2O (1:9, v/v) solution.
Fig.6. Fluorescence imaging of SiHa cells with HPIN. a) is bright image, b) is
fluorescence image of cytoplasm located dye (Lyso tracker red), c) is
fluorescence image of HPIN and Al3+, d) is fluorescence image of HPIN, e) is
merged image of located dye and HPIN/Al3+, f) is merged bright image and
fluorescence image of located dye and HPIN/Al3+.
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Scheme 1
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Fig.1
1200
12
1000
800
600
400
200
0
0
500
550
600
650
700
Wavelength (nm)
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Fig.2
Equation
y = a + b*
Adj. R-Squar 0.99305
20
15
10
5
Value Standard Err
Intercept 1.5505 0.28523
B
B
Slope
19.970
0.5034
0
0.0
0.2
0.4
0.6
0.8
1.0
[Al3+], *10-6 mol/L
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Fig.3
750
600
450
300
150
0
0.0
0.2
0.4
0.6
0.8
1.0
[Al3+]/([Al3+]+ [HPIN])
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Fig.4
1000
800
600
400
200
0
Al3+
HPIN and others ions
500
550
600
650
700
Wavelength (nm)
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Fig. 5
21
18
15
12
9
6
3
0
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Fig. 6
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Graphical Abstract
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Highlights
A simple and efficient chemosensor HPIN is designed and synthesized.
The chemosensor has high selectivity and sensitivity for Al3+.
It is a fluorescence “off-on” switch for Al3+.
The coordination mode of HPIN with Al3+ is a 1:1 binding stoichiometry.
Potential utilization of HPIN as intracellular sensors of Al3+ was examined.
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