A significant fluorescent “turn-on” chemosensor for Al3+ detection and application in real sample, logic gate and bioimaging

Article abstract of DOI:10.1016/j.ica.2019.118962

A novel naphthaldehyde–benzothiazole conjugated sensor Z was successfully synthesized and characterized. Chemosensor Z showed highly selective and sensitive for the detection of Al³⁺ in DMF/H₂O (v/v, 4/6) attributed to the combined c

Full text of DOI:10.1016/j.ica.2019.118962

Accepted Manuscript
Research paper
3
+
A significant fluorescent “turn-on” chemosensor for Al detection and appli-
cation in real sample, logic gate and bioimaging
Shuang Zeng, Shi-Jie Li, Ting-Ting Liu, Xue-Jiao Sun, Zhi-Yong Xing
PII:
S0020-1693(19)30660-7
https://doi.org/10.1016/j.ica.2019.118962
118962
DOI:
Article Number:
Reference:
ICA 118962
To appear in:
Inorganica Chimica Acta
Received Date:
Revised Date:
Accepted Date:
9 May 2019
11 June 2019
11 June 2019
Please cite this article as: S. Zeng, S-J. Li, T-T. Liu, X-J. Sun, Z-Y. Xing, A significant fluorescent “turn-on”
3
+
chemosensor for Al detection and application in real sample, logic gate and bioimaging, Inorganica Chimica
Acta (2019), doi: https://doi.org/10.1016/j.ica.2019.118962
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers
we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and
review of the resulting proof before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

3
+
A significant fluorescent “turn-on” chemosensor for Al detection
and application in real sample, logic gate and bioimaging
Shuang Zeng a, 1, Shi-Jie Li b, 1, Ting-Ting Liu , Xue-Jiao Sun , Zhi-Yong Xing
a
a
a,
*
a
Department of Applied Chemistry, College of Science, Northeast Agricultural University, Harbin
50030, PR China. Tel: +86 451 5519 1810, Fax: +86 451 5519 0317
College of Life Science, Northeast Agricultural University, Harbin 150030, PR China
Corresponding authors
1
b
*
E-mail addresses: zyxing@neau.edu.cn
1
These authors contributed equally to this work and should be considered co-first authors.
Abstract: A novel naphthaldehyde–benzothiazole conjugated sensor Z was successfully
synthesized and characterized. Chemosensor Z showed highly selective and sensitive for the
3
+
detection of Al in DMF/H O (v/v, 4/6) attributed to the combined contribution of excited-state
2
intramolecular proton transfer (ESIPT), C=N isomerization and chelation enhanced fluorescence
(
CHEF). The binding ratio of Z to Al3+ was 1:1 which was further determined by job’s plot and
-7
-8
3+
HRMS. The detection limit was calculated 4.56×10 M and 5.09×10 M in corresponding Al
concentration range of 0-22 μM and 24-44 μM, respectively. Furthermore, Z was successfully
practiced for the Al3+ quantitative analysis in real water samples, logic gate construction and
bioimaging in human stromal cells (HSC).
3
+
Key Words: fluorescent; turn on; Al ; cell imaging
1

1
. Introduction
As we all known, metal ions play an important role in environmental and biological systems.
As the third richest element in nature, the excessive accumulate of Al3+ in the human body can
induce various diseases mainly exhibited in Alzheimer’s disease, anemia, Parkinson’s disease,
hemochromatosis and amyotrophic lateral sclerosis [1-6]. Moreover, high concentrations of
aluminum ions also have serious toxic effects on the ecosystem such as inhabitation of the growth
of plant roots, damaging the living condition of freshwater fishes [7-9]. Undoubtedly, the
monitoring of aluminum ions in environmental and biological systems is of important significance.
In recent years, compared with traditional analytical techniques, fluorescence based
technology has gradually become a frontrunners in the field of analytical detection due to its
merits including simple process of detecting samples, low cost, naked-eye recognition, high
sensitivity and specificity [10-14]. Furthermore, fluorescent probes based on various derivatives
such as rhodamine [15-19], naphthalene [20-22], benzothiazole [23-25] and naphthalimide [26-30]
had been reported for the detection of metal ions. Although many fluorescent probes for
identifying Al3+ were reported so far [31-39], due to these shortcomings of Al3+ such as strong
hydration ability resulted in poor coordination and lack of spectroscopic characteristics, it is still
more difficult in the detection of Al3+ than other metal ions [40, 41]. Therefore, designing a
3
+
selective and sensitive fluorescent probe for Al in aqueous media is still full of challenging.
2
-(2’-Hydroxyphenyl) benzothiazole (HBT) is the most well-known ESIPT fluorophore,
fluorescent probes are often designed using a strategy in which oxygen atoms on a phenolic
hydroxyl coordinates with a metal ion to inhibit excited-state intramolecular proton transfer
(ESIPT) to alter the fluorescent properties [42-44]. Especially, thiazole ring including N atom can
2

supply a hard base unit for the recognition the hard acid Al3+ [26, 38]. Moreover, 2-hydroxy-1-
naphthaldehyde is also an excellent building block which is usually to construct fluorescent schiff-
base probe through condension of 2-hydroxy-1-naphthaldehyde (HNA) with various primary
amines to achieve the detection of special analyte using the ESIPT mechanism [45, 46]. Herein,
we designed and synthesized a novel fluorescent probe Z, which contained the deprotonation
phenolic hydroxyl of HBT to provide more binding sites and the ESIPT-based fluorophore unit
through the condension of hydrazine hydrate and 2-hydroxy-1-naphthaldehyde (Scheme 1). The
result showed that sensor Z was highly specific for Al3+ ion through significant fluorescent “turn-
on” response in aqueous DMF (N, N-dimethylformamide) medium. The optical properties of
sensor Z for Al3+ were investigated using fluorescence response, and its application in real sample
detection, logic gate construction and cell imaging were also reported.
O
O
O
S
O
OH
OH
NH2
SH
S
hydrazine hydrate
Na2S2O5
BrCH2COOC2H5/K2CO3
3
CH CH OH,80℃
+
N
3
2
N
DMF,110℃
CH CN,80℃
2
1
NH2
NH
HO
O
O
O
O
O
O
N
N
O
NH
ESIPT
NH
S
2-hydroxy-1-naphthaldehyde
H
S
S
N
CH3CH2OH, 80℃
N
N
3
Z (Enol form)
Z (Keto form)
Scheme 1. Synthesis of probe Z.
2
. Experimental
2
.1. Materials and methods
All chemicals were analytical or spectroscopic grade which were obtained commercially and
used without further purification. All metal ion solutions were prepared by its perchlorate or
3

nitrate salts.
Melting point was recorded on a Beijing XT4-100X microscopic melting point apparatus.
1
FT-IR spectra were measured by SEWERE ALPHA-T (Bruker Company, DEU). H NMR spectra
and 13C NMR spectra were recorded on a Bruck AV-600 spectrometer using DMSO-d as the
6
solvent. The model of PHS-3C meter (Shanghai, China) was used for the pH measurement.
Absorption spectra were recorded on a Shimadzu UV-2700 UV–vis spectrometer at 25 ℃ .
Fluorescence measurements were measured on a Perkin Elmer LS55 fluorescence spectrometer.
Mass spectra were determined on a Waters Xevo UPLC/G2-SQ Tof MS spectrometer.
The detection limit (LOD) of sensor Z for Al3+ was calculated based on 3σ/k, where σ is the
standard deviation of the blank measurements, and k is the slope of the intensity ratio versus
sample concentration plot
The quantum yield was calculated according to the equation: ΦF(X) = ΦF(S) (A F /A F )
S
X
X
S
2
(
n /n ) . Where A is the absorbance at the excitation wavelength, F is the area under the corrected
X S
emission curve, and n is the refractive index of the solvents used. Subscripts S and X refer to the
standard and to the unknown, respectively. The fluorescence quantum yield was determined by
using quinine sulfate (ΦF(S) = 0.55) as reference with the literature method [47].
The Z-Al3+ complex was obtained as yellow solid by refluxing the solution of ethanol
3
+
containing probe Z and Al(NO ) ·9H O, and the FT-IR spectrum of Z and Z-Al complex were
3
3
2
measured on a Perkin-Elmer IR spectrophotometer.
2
2
.2. Synthesis
Compounds 1-3 were synthesized according to the previously reported method [39, 48].
.2.1. Synthesis of compound 2
4

The compound 1 (400 mg, 1.64 mmol) and K CO (456 mg, 3.32 mmol) were added into
2
3
acetonitrile (14 mL). Then the ethyl bromoacetate (184 μL, 1.64 mmol) was added dropwise to the
mixture and refluxed for 1 h. After the solvent was removed under vacuum, the compound 2 was
obtained by column chromatography on silica gel using ethyl acetate/dichloromethane (v/v, 1/50).
1
Yield: 404 mg, 75%. H NMR (600 MHz, DMSO) (Fig. S1) δ (ppm) 8.28 (s, 1H), 8.12 (d, J = 7.8
Hz, 1H), 8.07 (d, J = 7.8 Hz, 1H), 7.54 (t, J = 7.8 Hz, 1H), 7.44 (t, J = 7.8 Hz, 1H), 7.33 (d, J = 8.0
Hz, 1H), 7.13 (d, J = 8.4 Hz, 1H), 5.09 (s, 2H), 4.21 (q, J = 7.2 Hz, 2H), 2.37 (s, 3H), 1.23 (t, J =
7
.2 Hz, 3H).
2
.2.2. Synthesis of compound 3
To a solution of compound 2 (200 mg, 0.62 mmol) in ethanol (20 mL) was added hydrazine
hydrate (2 mL, 41.23 mmol) and the mixture was refluxed for 2 h under stirring. After the reaction
was completed, the precipitate was filtered. Finally,washed it 5 times with ethanol to afford
1
compound 3. Yield: 166 mg, 86%. H NMR (600 MHz, DMSO) (Fig. S2) δ (ppm) 9.57 (s, 1H),
8
7
2
2
.17 (d, J = 1.7 Hz, 1H), 8.12 (d, J = 7.8 Hz, 2H), 8.10 (d, J = 7.8 Hz, 2H), 7.55 (t, J = 7.2 Hz, 1H),
.45 (t, J = 7.8 Hz, 1H), 7.34 (d, J = 8.4 Hz, 1H), 7.12 (d, J = 8.4 Hz, 1H), 4.76 (s, 2H), 4.42 (s,
H), 2.37 (s, 3H).
.2.3. Synthesis of probe Z
The compound 3 (111 mg, 0.35 mmol) and 2-hydroxy-1-naphthaldehyde (61 mg, 0.35 mmol)
were refluxed in ethanol (16 mL) for 5 h and the progress of reaction was monitored by TLC.
After cooling to 25 °C, the probe Z as white solid was obtained by filtered and washed with
1
ethanol. Yield: 156 mg, 94%. E-configuration: H NMR (600 MHz, DMSO) (Fig. S3) δ (ppm)
1
2.43 (s, 1H, 67%), 12.05 (s, 1H, 67%), 9.33 (s, 1H, 67%), 8.29 (s, 1H), 8.28 (d, J = 10.2 Hz, 1H,
5

6
7%), 8.15 (d, J = 7.8 Hz, 1H, 67%), 8.08 (d, J = 7.8 Hz, 1H), 7.94 (d, J = 9.0 Hz, 1H, 67% ), 7.89
d, J = 8.4 Hz, 1H), 7.57 (t, J = 8.4 Hz, 1H), 7.55 (t, J = 8.4 Hz, 1H, 67%), 7.44 (t, J = 7.8 Hz, 1H),
.40 (t, J = 7.8 Hz, 1H), 7.35 (d, J = 7.2 Hz, 1H, 67% ), 7.23 (d, J = 9.0 Hz, 1H), 7.22 (d, J = 8.4
(
7
1
3
Hz, 1H, 67%), 5.05 (s, 2H, 67%), 2.39 (d, J = 5.4 Hz, 3H). C NMR (151 MHz, DMSO) (Fig. S4)
δ (ppm) 164.05, 162.84, 158.40, 154.37, 152.10, 147.58, 136.04, 133.43, 133.34, 132.04, 131.55,
1
1
29.47, 129.40, 128.32, 128.25, 126.75, 125.46, 124.06, 122.92, 122.33, 122.09, 121.60, 119.25,
14.61, 109.01, 67.94, 20.58.
1
Z-configuration: H NMR (600 MHz, DMSO) (Fig. S3) δ (ppm) 11.70 (s, 1H, 33%), 10.74 (s,
1
1
H, 33%), 8.91 (s, 1H, 33%), 8.76 (d, J = 9.0 Hz, 1H, 33%), 8.29 (s, 1H), 8.08 (d, J = 7.8 Hz,
H), 8.07 (d, J = 8.4 Hz, 1H, 33%), 7.89 (d, J = 8.4 Hz, 1H), 7.85 (d, J = 7.8 Hz, 1H, 33%), 7.57 (t,
J = 8.4 Hz, 1H), 7.51 (t, J = 7.8 Hz, 1H, 33%),7.44 (t, J = 7.8 Hz, 1H), 7.40 (t, J = 7.8 Hz, 1H),
7
3
1
1
2
.38 (t, J = 8.4 Hz, 1H, 33%), 7.38 (d, J = 8.4 Hz, 1H, 33%), 7.23 (d, J = 9.0 Hz, 1H), 5.48 (s, 1H,
3%), 2.39 (d, J = 5.0 Hz, 3H). 13C NMR (151 MHz, DMSO) (Fig. S4) δ (ppm) 168.29, 163.00,
57.40, 154.65, 152.03, 143.76, 136.14, 133.14, 133.01, 131.72, 130.67, 129.26, 129.16, 128.62,
28.37, 126.63, 125.30, 123.90, 122.84, 122.33, 122.18, 121.56, 118.59, 113.84, 110.68, 66.30,
0.58.
+
+
HRMS m/z (TOF MS ES ) (Fig. S5): calcd for C H N O S: 468.1382 [M+H] ,
2
7
22
3
3
found:468.1383.
2
.3. Cell Culture and Staining
The fibroblast cell line, human stromal cell line (HSC), was purchased from ATCC (CRL-
003). For maintained HSC, cells were routinely cultured in mixture medium (DMEM: F-12=1:1),
4
which was supplemented with 10% heat-inactivated FBS, 100 U/mL penicillin, 100 μg/mL
6

streptomycin, and 1 mM sodiumpyruvate at 37 ℃, 5% CO . 48-hour after plant HSC into 6-well
2
5
plates with sterile cover glass at concentration of 10 cells/well, the media would be changed to
which without FBS or antibiotic. After the cells were incubated 2 hours with different amounts of
Al3+ (0, 10 and 50 μM), washed them 3 times with D-Hank’s to remove excess Al3+ on the cell
surface. Before stained with Z, cells were fixed by using a standard paraformaldehyde fixation
protocol and were rinsed with DMD/H O (5/5, v/v). And then cells were stained by incubating for
2
2
hours with Z (1 × 10−4 M). Lastly, the cover glass were mounted over slide glass with anti-
fluorescence quenching agent and imaged by fluorescence microscope.
3
. Results and Discussion
3
.1. Fluorescence studies of Z with different metal ions
Fluorescence selectivity experiments were conducted to investigate the fluorescence
responses of Z in the presence of diverse metal ions. As shown in Fig. 1a, the probe Z (10 μM)
itself almost showed no significant fluorescent emission with low quantum yield (ΦF(s) = 0.05) in
the solution of DMF/H O (4/6, v/v). This phenomenon might due to the probe Z exchanged in the
2
keto-enol form which caused the occurrence of ESIPT mechanism (Scheme 1), and the C=N
isomerization of Z also could greatly quench the fluorescence at the excited state [49, 50]. Upon
the addition of tested metal ions into the solution of probe Z, the fluorescence spectra showed that
only the addition of aluminum ions caused a remarkable fluorescence enhancement at 465 nm
with higher quantum yield (ΦF(s) = 0.82) after excitation at 390 nm (Fig. 1a). At the same time, the
easily visual detection of aluminum ions was also achieved under UV light of 365 nm, which
mainly manifested in a significant color changing from colorless to bright blue (Fig. 1a Inset).
This result could attribute to the coordination of Z with Al3+ through chelation–enhanced
7

fluorescence (CHEF) mechanism, which resulted in the inhibition of the ESIPT processes and
C=N isomerization and further increasing the rigidity of the molecular assembly [51, 52].
Fig. 1. (a) Fluorescence spectra of Z (10 μM) upon addition of various metal ions (5 equiv.) in DMF/H
v/v). Inset: The color change of Z after the addition of Al3+ under UV light of 365 nm; (b) Fluorescence spectral
changes of Z (10 μM) added with different concentrations of Al3+ in DMF/H
O (4/6, v/v). Inset: The fluorescence
2
O (4/6,
2
3
+
intensity of Z at 440nm versus the concentrations of Al .
3
+
The excellent fluorescence selectivity of probe Z for Al promoted us to further delve into the
fluorescence titration experiments (Fig. 1b). The result showed that the fluorescence intensity of
the probe Z gradually increased with the addition of Al3+ (0-5 equiv.) and almost no change when
the addition of Al3+ was up to 5 equivalents. Interestingly, as shown in Fig. 2, the fluorescence
intensity of Z has a good linear relationship with the concentration of Al3+ added in the
concentration range of 0-22 μM and 24-44 μM, respectively. The detection limits (calculated
using 3σ/k, where σ is the standard deviation of the blank measurements, and k is the slope of the
intensity ratio versus sample concentration plot, reported by previous report [42]) were calculated
-7
-8
to be 4.56×10 M for the concentration ranging from 0 μM to 22 μM and 5.09×10 M for the
concentration in the range of 24-44 μM. This characteristic of two linear relationships in different
concentration ranges of Al3+ indicated that the probe had the potential to quantitatively detect
aluminum ions in different ranges. In addition, probe Z showed higher sensitivity to Al3+
according to the comparative analysis between Z and some previously reported sensors which
8

were summarized in Table 1.
Fig. 2. The fluorescence intensity of probe Z at 465 nm as a function of Al3+ concentration range (a) 0-22 μM and
(b) 24-44 μM.
3
+
Table 1 Comparison of different properties of Z with recently reported probes used as fluorescent sensor for Al .
Binding
Ref.
Detection Medium
LOD
Recovery
Application
Constants
-
8
6
-1
[
[
[
31]
32]
33]
Ethanol/H
2
O (95/5, v/v)
O (1/1, v/v)
5.2×10 M
1.74×10 M
NR
test strips
cell imaging
cell imaging
-6
3
-1
EDTA2-
EDTA2-
DMSO/H
2
2.9×10 M
1.5×10 M
-7
6
-1
Ethanol/H
Ethanol/H
2
O (1:1, v/v)
O (7:3, v/v)
3.7×10 M
7.62×10 M
2
-7
5
-1/2
[35]
1.0×10 M
1.83×10 M
NR
cell imaging
HEPES pH = 7.4
Tris-HCl buffer
pH=7.2
-
7
EDTA2-
S2-
[36]
[37]
[39]
[41]
[43]
3.2×10 M
NR
real water samples
cell imaging
-9
4
-1
aqueous solution
4.1×10 M
4.67×10 M
cell imaging
-7
4
-1
EDTA2-
EDTA2-
EDTA2-
DMF/H
2
O (1/9, v/v)
1.9×10 M
1.04×10 M
real water samples
-7
4
-1
Ethanol
2.2×10 M
1.89×10 M
None
HEPES buffer
pH=7.4
test strips
cell imaging
-
6
2.2×10 M
NR
This
cell imaging
-8
4
-1
EDTA2-
DMF/H
2
O (4:6, v/v)
5.09×10 M
2.35×10 M
work
real water samples
LOD: The limit of detection; NR: Not reported in the corresponding paper.
3
+
To further investigate the selectivity of probe Z to Al , the competitive experiment was
3
+
conducted by mixing the DMF/H O solution containing probe Z (10 μM) and Al (50 μM) with
2
3
+
other tested metal ions (Fig. 3). As for the fluorescence intensity of Z-Al system, it almost kept a
9

constant by the addition of large amounts of other metal ions except Cr3+ which had an ignorable
effect on the intensity of chemosensor Z, indicating that the probe Z could quantitatively detect
3
+
Al in the presence of these tested metal ions.
Fig. 3. Fluorescence intensity of Z (10 µM) at 465 nm upon addition of various metal ions (50 µM) in the presence
Al3+ (50 µM) in DMF/H
O (4/6, v/v), (λex = 390nm).
2
3
.2. Investigation of Binding sites and sensing mechanism
In order to better explicit the sensing mechanism of probe Z to Al , the binding mode
3
+
between the probe Z and Al3+ was first verified by Job's method and ESI-MS analysis. As shown
in Fig. 4, when the mole fraction of Al3+ was reached 0.5, the fluorescence intensity of the
complex Z-Al3+ reached the maximum, showing the 1:1 binding stoichiometry between probe Z
3
+
and Al . Furthermore, the ESI mass spectrum showed a peak at m/z 565.1497, designate to [Z-
+
3+
2
H + Al + DMF] (calcd. m/z 565.1490) in the ESI mass spectrum (Fig. 5). The ESI-MS analysis
3
+
matched with the Job's plot analysis and further confirmed the 1:1 binding mode of Z with Al .
4
-1
Based on the Benesi–Hildebrand plot, the association constant was calculated as 1.45×10 M and
4
-1
2
.35×10 M for the concentration range 0-22 and 24-44 μM, respectively (Figs. S6 and S7).
1
0

3
+
3+
3+
3+
Fig. 4. Job plot of the system of Z-Al . {[Al ]/([Al ] + [Z])} is the molar fraction of Al ion.
Fig. 5. ESI–MS spectrum of the DMF solution containing Z (50 μM) and Al3+ (5 equiv.).
In addition, the coordination mode of the probe Z with Al3+ was further analyzed by FT-IR
1
spectra (Fig. S8) and H NMR titration experiment. As for the FT-IR spectra of probe Z, the peaks
-1
-1
at, 3305 cm and 1216 cm , were attributed to O-H stretching and C-O stretching of phenolic
hydroxyl, respectively. Moreover, peaks at 3217 cm-1 and 1689 cm-1 were assigned to N-H
3
+
stretching and C=O stretching of amide, respectively. After complexation with Al , the
characteristic peaks of N-H absorption and C=O absorption of the amide were disappeared, and
-1
3+
the appearance of an absorption peak at 1601 cm , indicated that one probable binding site to Al
was O atom of the deprotonation of enolized amide group. Moreover, the characteristic OH
-1
-1
vanished and the C-O moved to higher wavenumbers form 1216 cm to 1322 cm , indicating the
3
+
interaction of Al with the O atom of deprotonated of phenolic hydroxyl.
1
1

1
3+
6
Fig. 6. H NMR spectra of Z with Al in DMSO-d .
1
H NMR titration was performed in DMSO-d illustrated in Fig. 6, the protons of hydroxyl
6
(
H14 and H ) and the protons (H and H ) of amide was due to (Z)- and (E)-configurations
14’ 16 16’
3
+
resulting from the C=N isomerizationn of the probe Z itself. Upon the addition of Al , due to the
difference in the two spatial configurations, the protons of hydroxyl (H ) at 12.42 ppm and (H )
1
4
14’
at 10.74 ppm were all disappeared, indicating the coordination of Al3+ with oxygen atom came
from the deprotonation of phenolic hydroxyl whatever in the (E)-configuration or (Z)-
configuration.
According to the above analysis including Job's plot, ESI–MS, FT–IR spectra comparison
1
3+
and H NMR titration, a plausible bonding fashion between Z and Al was proposed (Scheme 2).
1
2

ESIPT ON
HN
ESIPT OFF
CHEF ON
N
Al3+
N
N
HO
O
Al3+
O
O
O
O
Solvent
N
S
N
S
Solvent:DMF
Scheme 2. Plausible binding fashion of probe Z with Al3+ ions.
3
.3. Relationship between pH and fluorescence intensity of probe Z
Furthermore, in order to investigate the ability of probe Z on the recognition of Al3+ at
different pH conditions, the fluorescent intensity of complex Z-Al3+ centred at 465 nm were
measured at different pH ranging from 2 to 13 (Fig. 7). The result showed that probe Z itself was
without any fluorescence emission in the range of pH from 2 to13. However, upon addition of
3
+
Al , the fluorescence intensity of the probe Z was significantly enhanced in the range of pH 4-7,
3
+
which indicated that the probe Z could recognize Al in neutral to acidic medium.
Fig. 7. The fluorescence intensity changes (λem= 465 nm) of Z and Z-Al3+ solution at various pH conditions (pH =
2
-13).
3
.4. Reversibility of Z for Al3+
Reversibility, an important factor in determining whether a probe can be repeatedly detected,
plays an important role in practical applications. In the reversibility experiment, based on the
conclusion we had previously analyzed, the probe Z and the aluminum ion was coordinated in the
1
3

form of chelation to generate fluorescence, so we used the common metal complexing agent
3
+
Na EDTA as chelating ligand to the solutions of Z-Al . Upon the addition of Na EDTA, the
2
2
3
+
3+
fluorescence spectra of Z-Al were all similar to that of probe Z without addition of Al (Fig. S9).
Moreover, when Al3+ ions were added to the mixture of Z + Al3+ + Na EDTA, the fluorescence
2
intensity turned on again (Fig. 8a), and the result showed that this reversible cycle could be
repeated at least 5 times through alternate addition of Na EDTA and Al3+ (Fig. 8b). This result
2
showed that this reversible cycle performance further enhanced the potential application of probe
Z in construction of logic gate.
Fig. 8. (a) The color changes of solution Z upon alternate addition of Al3+ and EDTA under UV light (λem = 365
nm); (b) fluorescence intensity of Z at 465 nm by alternate addition of Al3+ and EDTA.
4
. Application of chemosensor Z
4
.1. Detection of Al3+ in real water samples
In order to investigate the applicability of the probe Z to the detection of Al3+ in real water
samples, different concentrations of Al3+ were added to water samples, and the results were
analyzed through the previously calculated linear relationship (Table 2). The results showed that
3
+
the probe Z had high recovery and precision for the detection of Al in these tested water samples,
which also indicated that it could be applied to the analysis and detection of Al3+ in environmental
water samples.
1
4

Table 2 Determination of Al3+ in water samples.
Water samples
studied
Amount of standard
Total Al3+ found
Recovery of Al3+
(n=3) added (%)
RSD
(%)
Relative
Al3+ added (μmol/L)
(n=3) (μmol/L)
error (%)
5
8
4.96
8.03
99.20
100.38
101.33
104.80
103.13
101.50
0.90
0.39
2.28
0.51
2.69
1.91
-0.80
0.37
1.33
4.80
3.13
1.5
ultrapure water
2
4
24.32
5.24
5
Tap water
(Department of
8
8.25
Chemistry)
2
4
24.36
4
.2. Molecular Logic Gates
Based on the good reversible cycle performance of Z with Al3+ and EDTA, a logic gate could
be implemented on Boolean logic operations, which was a INHIBIT logic gate (Fig. 9). Since
3
+
there was significant fluorescence emission at 465 nm after the addition of Al , we set the
fluorescence signal at 465 nm as the output, the strong fluorescence intensity at 465 nm was On (1)
state and weak for Off (0) state. Al3+ and EDTA were respectively set as inputs In 1 and inputs In
2
, whose presence and absence were itemized as 1 and 0. According to the above mentioned basic
logic gates, we further installed the memory storage device to implement the reset operation of the
logic circuit. When the output was On (1) state, the input signal could be reset by the memory unit
to return the output to the off (0) state. Hence, the above setting could make the entire process to
be repeated for several times.
Fig. 9. (a) Logic circuit showing memory unit containing two inputs (In 1 and In 2) and one output; (b)
corresponding truth table.
1
5

4
.3. Cells Imaging
Considering imaging in biological systems was another important practical applicability for
one probe, we used the the human stromal cells (HSC) that was incubated different amounts of
3
+
Al and Z (0.1 mM) and then imaged by fluorescence microscope. As shown in Fig. 10 A and Fig.
1
0 B, the cells without any treatment and the cells incubated 2 hours with Z (0.1 mM) were all
3
+
emit any intracellular fluorescence. When the cells was incubated of Al (10 μM) and Z (0.1 mM),
a weak blue fluorescence was detected (Fig. 10 C). When cells were further treated with Al3+ (50
μM) and Z (0.1 mM), the blue fluorescence was significantly increased (Fig. 10 D). These results
3
+
indicated that the probe Z might became an Al tracer in biological systems.
Fig. 10. (A) The cells without any treatment; (B) incubation of cells with Z (0.1 mM) for 2 hours; (C) incubation
of cells with Al3+ (10 μM) and Z (0.1 mM); (D) incubation of cells with Al3+ (50 μM) and Z (0.1 mM).
5
. Conclusions
In summary, a novel naphthaldehyde–benzothiazole conjugated chemosensor Z was
successfully synthesized and characterized. Chemosensor Z was achieved in highly selective and
3
+
sensitive for the detection of Al in DMF/H O (v/v, 4/6) through significant fluorescence turn on.
2
The binding ratio of Z to Al3+ was 1:1 and the detection limit was calculated 4.56×10 M and
-7
1
6

-8
3+
5
.09×10 M in corresponding Al concentration range of 0-22 μM and 24-44 μM, respectively.
Furthermore, Z was successfully practiced for the Al3+ quantity analysis in real water samples,
logic gate and imaging in human stromal cells (HSC).
Acknowledgement
This work was supported by the Postdoctoral Scientific Research Developmental Fund of
Heilongjiang Province (No. LBH-Q14023), and the Research Science Foundation in Technology
Innovation of Harbin (No. 2017RAQXJ022).
Appendix A. Supplementary data
Supplementary data associated with this article can be found, in the online version, at
Reference
[
[
[
[
1] R. Azadbakht, M. Talebi, J. Karimi, R. Golbedaghi, Synthesis and characterization of a new
organic nanoparticle as fluorescent chemosensor for aluminum ions, Inorg. Chim. Acta 453
(2016) 728–734. https://doi.org/10.1016/j.ica.2016.09.042
2] R. Wang, G.Q. Jiang, X.H. Li, Two 5,5’-methylenebis(salicylaldehyde)-based Schiff base
fluorescent sensors for selective sensing of Al3+ in DMSO/H O solution, Inorg. Chim. Acta
2
4
55 (2017) 247–253. https://doi.org/10.1016/j.ica.2016.11.008
3] P.F. Good, C.W. Olanow, D.P. Perl, Neuromelanin–containing neurons of the substantia
nigra accumulate iron and aluminum in Parkinson’s disease: a LAMMA study, Brain Res.
5
93 (1992) 343-346. https://doi.org/10.1016/0006-8993(92)91334-B
4] G.D. Fasman, Aluminum and Alzheimer’s disease: model studies, Coordin. Chem. Rev. 149
1996) 125-165. https://doi.org/10.1016/S0010-8545(96)90020-X
(
1
7

[5] M. Kawahara , K. Muramoto , K. Kobayashi , H. Mori, Y. Kuroda , Aluminum Promotes the
Aggregation of Alzheimer′s Amyloid β-Protein in Vitro, Biochem. Bioph. Res. Co. 198
(1994) 531-535. https://doi.org/10.1006/bbrc.1994.1078
[6] L. Tang, S. Ding, K. Zhong, S. Hou, Y. Bian, X. Yan, A new 2-(2′-hydroxyphenyl)quinazolin-
3
+
4
1
(3H)-one derived acylhydrazone for fluorescence recognition of Al , Spectrochim. Acta A
74 (2017) 70–74. https://doi.org/10.1016/j.saa.2016.11.026
[
7] L. Godbold, E. Fritz, A. Hüttermann, Aluminum toxicity and forest decline, Proc. Natl. Acad.
Sci. U.S.A. 85 (1988) 3888-3892. https://doi.org/10.1073/pnas.85.11.3888
[
8] H. Sade, B. Meriga, V. Surapu, J. Gadi , M. S. L. Sunita, P. Suravajhala, P. B. Kavi Kishor,
Toxicity and tolerance of aluminum in plants: tailoring plants to suit to acid soils, Biometals
2
9 (2016) 187–210. https://doi.org/10.1007/s10534-016-9910-z.
[
9] J. BarcelÓ, C. Poschenrieder, Fast root growth responses, root exudates, and internal
detoxification as clues to the mechanisms of aluminium toxicity and resistance: a review,
Environ. Exp. Bot. 48 (2002) 75–92. https://doi.org/10.1016/S0098-8472(02)00013-8
3
+
[
10] R. Singh, S. Samanta, P. Mullick, A. Ramesh, G. Das, Al sensing through different turn-on
emission signals vis-à-vis two different excitations: Applications in biological and
environmental
https://doi.org/10.1016/j.aca.2018.03.053
11] S. M. Hossain, K. Singh, A. Lakma, R. N. Pradhan, A. K. Singh, A schiff base ligand of
realms,
Anal.
Chim.
Acta
1025
(2018)
172-180.
[
3
+
coumarin derivative as an ICT-Basedfluorescence chemosensor for Al , Sensors Actuators B
Chem. 239 (2017) 1109–1117. https://doi.org/10.1016/j.snb.2016.08.093
[12] L. Tang, X. Dai, X. Wen, D. Wu, Q. Zhang, A rhodamine–benzothiazole conjugated sensor
1
8

for colorimetric, ratiometric and sequential recognition of copper(II) and sulfide in aqueous
media, Spectrochim. Acta A 139 (2015) 329–334. https://doi.org/10.1016/j.saa.2014.12.055
13] T. Chen, T. Wei, Z. Zhang, Y. Chen, J. Qiang, F. Wang, X. Chen, Highly sensitive and
selective ESIPT-based fluorescent probes for detection of Pd2+ with large Stocks shifts, Dyes
Pigm. 140 (2017) 392-398. https://doi.org/10.1016/j.dyepig.2017.01.063
[
[
[
[
14] S. Goswami, K. Aich, A. K. Das, A. Manna, S. Das, A naphthalimide–quinoline based probe
for selective, fluorescence ratiometric sensing of trivalent ions, RSC Adv. 3 (2013) 2412–
2
416. http://doi.org/10.1039/C2RA22624C
15] M. Li, X. Zhang, Y. Fan, C. Bi, A novel fluorescent probe based on rhodamine hydrazone
3
+
derivatives bearing a thiophene group for Al , Luminescence 31 (2016) 851–855.
https://doi.org/10.1002/bio.3041
16] J.W. Jeong, B.A. Rao, J.Y. Lee, J.Y. Hwang, Y.A. Son, An ‘OFF–ON’ fluorescent
chemosensor based on rhodamine 6G-2-chloronicotinaldehyde for the detection of Al3+ ions:
Part
II,
Sensors
Actuators
B
Chem.
227
(2016)
227–241.
https://doi.org/10.1016/j.snb.2015.12.015
[17] Q. Huang, Q. Zhang, E. Wang, Y. Zhou, H. Qiao, L. Pang, F. Yu, A new “off–on”
fluorescent probe for Al3+ in aqueous solution based on rhodamine B and its application to
bioimaging,
https://doi.org/10.1016/j.saa.2015.07.062
18] Y. Yang, C.Y. Gao, J. Liu, D. Dong, Recent developments in rhodamine salicylidene
hydrazone chemosensors, Anal. Methods (2016) 2863–2871.
http://doi.org/10.1039/C6AY00135A
Spectrochim.
Acta
A
152
(2016)
70–76.
[
8
1
9

[
19] S. Sahana, S. Bose, S.K. Mukhopadhyay, P.K. Bharadwaj, A highly selective and sensitive
turn-on fluorescence chemosensor based on a rhodamine–adenine conjugate for Al3+ in
aqueous medium: Bioimaging and DFT studies, J. Lumin. 169 (2016) 334–341.
https://doi.org/10.1016/j.jlumin.2015.09.009
3
+
[
[
[
[
20] X. Yue, Z. Wang, C. Li, Z. Yang, Naphthalene-derived Al -selective fluorescent
chemosensor based on PET and ESIPT in aqueous solution, Tetrahedron Lett. 58 (2017)
4
532–4537. https://doi.org/10.1016/j.tetlet.2017.10.044
21] R. Azadbakht, M. Koolivand, J. Khanabadi, A New fluorescence chemosensor for Zn2+ with
a remarkable red shift in emission spectra, Anal. Methods 9 (2017) 4688-4694
http://doi.org/10.1039/C7AY01568B
22] J. Zhu, Y. Zhang, Y. Chen, T. Sun, Y. Tang, Y. Huang, Q. Yang, D. Ma, Y. Wang, M. Wang,
2
+
A Schiff base fluorescence probe for highly selective turn-on recognition of Zn ,
Tetrahedron Lett. 58 (2017) 365–370. https://doi.org/10.1016/j.tetlet.2016.12.041
23] V. Kachwal, I. S. Vamsi Krishna, L. Fageria, J. Chaudhary, R. K. Roy, R. Chowdhury, I. R.
Laskar, Exploring the Hidden Potential of Benzothiazole Based Schiff base “AIE and ESIPT”
active for pH Sensing, Intracellular Imaging and Ultrasensitive & Selective detection of
3
+
Aluminium (Al ), Analyst 143 (2018) 3741-3748. http://doi.org/10.1039/C8AN00349A
[24] H. Diao, L. Guo, W. Liu, L. Feng, A novel polymer probe for Zn(II) detection with
ratiometric fluorescence signal, Spectrochim. Acta
https://doi.org/10.1016/j.saa.2018.02.036
A
196 (2018) 274–280.
3
+
[
25] D. Yao, X. Huang, F. Guo, P. Xie, A new fluorescent enhancement chemosensor for Al and
Fe3+ based on naphthyridine and benzothiazole groups, Sensors Actuators B Chem. 256
2
0

(2018) 276–281. https://doi.org/10.1016/j.snb.2017.10.080
[
[
[
[
26] L. Kang, Z.Y. Xing, X.Y. Ma, Y.T. Liu, Y. Zhang, A highly selective colorimetric and
fluorescent turn-on chemosensor for Al3+ based on naphthalimide derivative, Spectrochim.
Acta A 167 (2016) 59–65. https://doi.org/10.1016/j.saa.2016.05.030
27] L. Kang, Y.T. Liu, N.N. Li, Q.X. Dang, Z.Y. Xing, J.L. Li, Y. Zhang, A schiff-base receptor
based naphthalimide derivative: Highly selective and colorimetric fluorescent turn-on sensor
3
+
for Al , J. Lumin. 186 (2017) 48–52. https://doi.org/10.1016/j.jlumin.2016.12.056
28] N.I. Georgiev, A.R. Sakr, V.B. Bojinov, Design and synthesis of a novel PET and ICT based
1
,8-naphthalimide FRET bichromophore as a four-input Disabled–Enabled-OR logic gate,
Sensors Actuators B Chem. 221(2015) 625–634. https://doi.org/10.1016/j.snb.2015.07.009
29] N.N. Li, S. Zeng, M.Q. Li, Y.Q. Ma, X.J. Sun, Z.Y. Xing, J.L. Li, A Highly Selective
Naphthalimide-Based Chemosensor: “Naked-Eye” Colorimetric and Fluorescent Turn-On
Recognition of Al3+ and Its Application in Practical Samples, Test Paper and Logic Gate, J.
Fluoresc. 28 (2018) 347–357. https://doi.org/10.1007/s10895-017-2197-9
[30] S. Janakipriya, N. R. Chereddy, P. Korrapati, S. Thennarasu, A. B. Mandal, Selective
interactions of trivalent cations Fe , Al and Cr3+ turn on fluorescence in a naphthalimide
3
+
3+
based single molecular probe, Spectrochim. Acta
https://doi.org/10.1016/j.saa.2015.08.044
A
153 (2016) 465–470.
[
31] S. Erdemir, O. Kocyigit, Dual recognition of Zn2+ and Al3+ ions by a novel probe containing
two fluorophore through different signaling mechanisms, Sensors Actuators B Chem. 273
(2018) 56–61. https://doi.org/10.1016/j.snb.2018.06.019
[
32] T. Anand, S.K.A. Kumar, S. K. Sahoo, A new Al3+ selective fluorescent turn-on sensor based
2
1

on hydrazidenaphthalic anhydride conjugate and its application in live cells imaging,
Spectrochim. Acta A 204 (2018) 105–112. https://doi.org/10.1016/j.saa.2018.06.033
33] Q. Wang, H. Sun, L. Jin, W. Wang, Z. Zhang, Y. Chen, A novel turn on and reversible sensor
for Al3+ and its applications in Bioimaging, J. Lumin. 203 (2018) 113–120.
https://doi.org/10.1016/j.jlumin.2018.06.047
[
[
34] K. Mal, B. Naskar, A. Mondal, S. Goswami, C. Prodhan, K. Chaudhuri, C. Mukhopadhyay,
Dihydroindeno[1,2-b]pyrroles: new Al3+ selective off–on chemosensors for bio-imaging in
living
HepG2
cells,
Org.
Biomol.
Chem.
16
(2018)
5920–5931.
http://doi.org/10.1039/C8OB01411F
[35] A. Sahana, A. Banerjee, S. Lohar, S. Das, I. Hauli, S. K. Mukhopadhyay, J. S. Matalobos, D.
Das, Naphthalene based highly selective OFF–ON–OFF type fluorescent probe for Al3+ and
2-
NO ions for living cell imaging at physiological pH, Inorg. Chim. Acta 398 (2013) 64–71.
https://doi.org/10.1016/j.ica.2012.12.012
[
36] Y. Zhou, J. Zhang, H. Zhou, X. Hu, L. Zhang, M. Zhang, A highly selective fluorescent probe
for Al3+ based on 4-aminoantipyrine, Spectrochim. Acta A 106 (2013) 68–72.
https://doi.org/10.1016/j.saa.2012.12.084
[
37] M. Maniyazagan, R. Mariadasse, M. Nachiappan, J. Jeyakanthan, N.K. Lokanath,S. Naveen,
G. Sivaraman, P. Muthuraja, P. Manisankar, T. Stalin, Synthesis of rhodamine based organic
nanorods for efficientchemosensor probe for Al (III) ions and its biological applications,
Sensors Actuators B Chem. 254 (2018) 795–804. https://doi.org/10.1016/j.snb.2017.07.106
38] S. Zeng, S.J. Li, X.J. Sun, M.Q. Li, Z.Y. Xing, J.L. Li, A benzothiazole-based chemosensor
for significant fluorescent turn-on and ratiometric detection of Al3+ and its application in cell
[
2
2

imaging,
Inorganica
Chimica
Acta
486
(2019)
654-662.
https://doi.org/10.1016/j.ica.2018.11.042
[
39] S. Zeng, S.J. Li, X.J. Sun, M.Q. Li, Y.Q. Ma, Z.Y. Xing, J.L. Li, A naphthalene-quinoline
based chemosensor for fluorescent “turn-on” and absorbance-ratiometric detection of Al3+
and its application in cells imaging, Spectrochim. Acta A 205 (2018) 276–286.
https://doi.org/10.1016/j.saa.2018.07.039
[
[
[
40] K. Soroka, R. S. Vithanage, D. A. Phillips, B. Walker, P. K. Dasgupta, Fluorescence
Properties of Metal Complexes of 8-Hydroxyquinoline-5-sulfonic Acid and Chromatographic
Applications, Anal. Chem. 59 (1987) 629-636. https://doi.org/10.1021/ac00131a019
41] G. Wang, J. Qin, C. Li, Z. Yang, A highly selective fluorescent probe for Al3+ based on
quinoline
Derivative,
Spectrochim.
Acta
A
150
(2015)
21–25.
https://doi.org/10.1016/j.saa.2015.05.041
42] J. Li, Y. Chen, T. Chen, J.N. Qiang, Z. Zhang, T. Wei, W. Zhang, F. Wang, X. Chen, A
benzothiazole-based fluorescent probe for efficient detection and discrimination of Zn2+ and
2
+
Cd , using cysteine as an auxiliary reagent, Sensors Actuators B Chem. 268 (2018) 446–455.
https://doi.org/10.1016/j.snb.2018.04.130
[43] Y. Chen, T. Wei, Z. Zhang, T. Chen, J. Li, J. Qiang, J. Lv, F. Wang, X. Chen, A
benzothiazole-based fluorescent probe for ratiometric detection of Al3+ in aqueous medium
and
living
cells,
Ind.
Eng.
Chem.
Res. 56 (2017)
12267–12275.
https://doi.org/10.1021/acs.iecr.7b02979
[44] B. Gu, L. Huang, W. Su, X. Duan, H. Li, S. Yao, A benzothiazole-based fluorescent probe for
distinguishing and bioimaging of Hg2+ and Cu , Anal. Chim. Acta 954 (2017) 97-104.
2+
2
3

https://doi.org/10.1016/j.aca.2016.11.044
[45] S. B. Roy, K. K. Rajak, A quinoline appended naphthalene derivative based AIE active
“
turn–on” fluorescent probe for the selective recognition of Al3+ and colourimetric sensor for
2
+
Cu : Experimental and computational studies, J. Photochem. Photobiol. A 332 (2017) 505–
14. https://doi.org/10.1016/j.jphotochem.2016.09.015
46] Z. Liao, Y. Liu, S.F. Han, D. Wang, J.Q. Zheng, X.J. Zheng, L.P. Jin, A novel
5
[
acylhydrazone-based derivative as dual-mode chemosensorfor Al , Zn and Fe3+ and its
applications in cell imaging, Sensors Actuators B Chem. 244 (2017) 914–921.
https://doi.org/10.1016/j.snb.2017.01.074
3
+
2+
[
47] J. Olmsted, Calorimetric determinations of absolute fluorescence quantum yields, J. Phys.
Chem. 83 (1979) 2581-2584. https://doi.org/10.1021/j100483a006
[
48] C. Chang, F. Wang, J. Qiang, Z. Zhang, Y. Chen, W. Zhang, Y. Wang, X. Chen,
Benzothiazole-based fluorescent sensor for hypochlorite detection and its application for
biological
imaging,
Sensors
Actuators
B
Chem.
243
(2017)
22–28.
https://doi.org/10.1016/j.snb.2016.11.123
[49] Y. Wang , Z.Y. Ma, D.L. Zhang, J.L. Deng, X. Chen, C.Z.Xie, X. Qiao, Q.Z. Li, J.Y. Xu,
Highly selective and sensitive turn-on fluorescent sensor for detection of Al3+ based on
quinoline-base Schiff base, Spectrochim. Acta
https://doi.org/10.1016/j.saa.2018.01.049
A
195 (2018) 157–164.
[50] N. Yadav, A. K. Singh, A turn-on ESIPT based fluorescent sensor for detection of aluminum
ion with bacterial cell imaging and logic gate applications, Mat. Sci. Eng. C 90 (2018) 468–
4
75. https://doi.org/10.1016/j.msec.2018.04.087
2
4

[51] R. K. Pathak, V. K. Hinge, A. Rai, D. Panda, C. P. Rao, Imino−Phenolic−Pyridyl Conjugates
2
+
of Calix[4]arene (L and L ) as Primary Fluorescence Switch-on Sensors for Zn in Solution
1
2
and in HeLa Cells and the Recognition of Pyrophosphate and ATP by [ZnL ], Inorg. Chem.
2
5
1 (2012) 4994−5005. https://doi.org/10.1021/ic202426v
[
52] J. Feng, L.X. Duan, Z.B. Shang, J.B. Chao, Y. Wang, W.J. Jin, Colorimetric and fluorometric
dual sensing of trace water in methanol based on a Schiff Base-Al3+ ensemble probe,
Spectrochim. Acta A 201 (2018) 185–192. https://doi.org/10.1016/j.saa.2018.05.016
2
5

2
6

Highlights
●
●
Chemosensor Z was synthesized and characterized.
3
+
Chemosensor Z exhibits significant fluorescence response to Al with
a 400-fold fluorescence enhancement
3
+
●
●
The limit of detection (LOD) and binding constant for Al were
-8
4
-1
5
.09×10 M and 2.35×10 M , respectively.
3
+
Z was successfully applied in real sample detection of Al and cell
imaging in HSC.
2
7