A novel sensitive fluorescent turn-on probe for rapid detection of Al3+ and bioimaging

Article abstract of DOI:10.1039/c4ra14177f

Taking advantage of the condensation reaction of 1-(2-hydroxyphenyl)ethanone and a rhodamine-B derived hydrazide, the first simply-structured rhodamine based probe L for the detection of Al³⁺ with high efficiency was designed and synthesized wh

Full text of DOI:10.1039/c4ra14177f

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A novel sensitive fluorescent turn-on probe for
rapid detection of Al3+ and bioimaging†
Cite this: RSC Adv., 2015, 5, 5244
Shuai Xia,a Si-Yu Xiao,a Qing-Qing Hong,a Jing-Rong Zou,a Sen Yang,a
b
a
*
Mu-Xue Zhang and Hua Zuo
Taking advantage of the condensation reaction of 1-(2-hydroxyphenyl)ethanone and a rhodamine-B
derived hydrazide, the first simply-structured rhodamine based probe L for the detection of Al3+ with
high efficiency was designed and synthesized which could be applied in water solutions. Spectroscopy
showed that the probe responded quickly and selectively to Al3+ over other metal ions with remarkable
fluorescence enhancement (43-fold) after 10 equiv. of Al3+ were added. Sensing of Al3+ was proved to
be effective over a wide pH range from 4.9 to 8.5 and the limit of the detection was calculated as 1.63 ꢀ
10ꢁ7 M by the fluorescence titration experiment. Besides, the probe L is characterized with good stability
and performed perfectly in a reversibility test with EDTA. Furthermore, live-cell imaging of HeLa cells
revealed the cell permeability of the probe, showing no toxicity in cultured cells by MTT method, which
indicated that L could be applied in living organisms.
Received 9th November 2014
Accepted 11th December 2014
DOI: 10.1039/c4ra14177f
www.rsc.org/advances
disequilibrium of aluminium homeostasis is implicated in
various kinds of diseases, such as Al-related bone disease
(ARBD),17 microcytic hypochromic anemia18 and especially the
noted Parkinson's disease.19 According to a WHO report, the
average daily human intake of aluminium is approximate 3–10
mg and the tolerable weekly aluminium intake in the human
body is estimated to be 7 mg kgꢁ1 body weight.20
Introduction
The uorescence chemosensing technique, characterized by
high sensitivity and selectivity, short response time, operational
simplicity and a wide range of applicability, stands out among
the many sensing techniques suitable for recognizing metal
ions and has featured extensively in analytical chemistry.1–5
Besides the detection of metal ions, this technique has been
applied in sensing pesticides, dynamite, biomolecules and even
cancer cells.6–11 Furthermore, compared with traditional
sensing techniques such as atomic absorption spectroscopy,
inductively coupled plasma-mass spectroscopy and inductively
coupled plasma-atomic emission spectroscopy, uorescence
chemosensors turn out to be more cost-efficient.12,13
Aluminum, the most abundant metal and the third most
prevalent element in the biosphere, are widely dispersed and
applied in modern world: in natural water body, food addic-
tives, medicines and as certain kinds of light alloy. However, the
intensied environmental acidication enables to dissolve
more Al minerals at lower pH, resulting in more amount of the
Al3+ available14 which is fatal to the living plants.15 On the other
hand, although it is proverbial that aluminum is a non-essential
element for living system, the size and the charge of Al3+ make it
a competitive inhibitor of several essential elements of similar
properties such as Mg2+, Ca2+ and Fe3+.16 Besides, the
However, due to the poor coordination ability of Al3+
compared to transition metals and the lack of spectroscopic
properties, the detection of Al3+ has always been problematic.21
To our best knowledge very few Al3+ selective uorescence
probes have been reported, majority of which possess the
drawbacks: the water solubility of Al3+ probe derived from 8-
hydroxyquinoline is very poor,22 the salicylaldehyde Schiff based
Al3+ probe suffers from low stability23 and the uorescence
sensor using a molecularly imprinted recognition receptor for
the detection of Al3+ is strongly interfered by Cu2+
.
Further-
24
more, because of the toxicity to the living cells, the practical use
of some Al3+ chemosensors is severely hampered.25,26
For another side, the introduction of rhodamine skeleton to
the molecule could produce the emission of long-wavelength
uorophore, which is preferred to be considered as reporting
group for analyte so as to avoid the inference of background
uorescence (<400 nm).27,28 Besides, featured as high quantum
yields, large extinction coefficient, great photostability, good
water solubility and low toxicity, rhodamine framework is an
ideal mode for constructing turn-on uorescence chemo-
sensors.29–31 A large number of rhodamine-based derivatives
have been reported to perform as probes to detect metal ions for
various intentions.32–41 However, no rhodamine-based Al3+
selective uorescence probes have been reported by now
aCollege of Pharmaceutical Sciences, Southwest University, Chongqing, 400716, China.
E-mail: zuohua@swu.edu.cn; Fax: +86 23 6825 1225; Tel: +86 23 6825 1225
bCollege of Resources and Environments, Southwest University, Chongqing, 400716,
China
† Electronic supplementary information (ESI) available. See DOI:
10.1039/c4ra14177f
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because the poor coordination ability of Al3+ makes the probes spectrometer, using CDCl3 as solvent and TMS as internal stan-
to suffer from interference by other metals. Besides, 1-(2- dard. CDCl3 was used as delivered from Adamas Co., Ltd.
hydroxyphenyl)ethanone, with one hydroxyl which may (Shanghai, China). Chemical shis were reported in parts per
enhance the solubility and coordination ability of probe, could million. HRMS spectra were recorded on a Q-TOF6510 sepctro-
be attached to the rhodamine-B frame for that the acetyl is graph (Agilent). UV-vis spectra were recorded on a UV-2550
possible to be condensed with the rhodamine-B derivatives. (Hitachi). Fluorescent measurements were recorded on a F-4500
Therefore, we believe that it is feasible to construct novel FL Spectrophotometer (Hitachi). The pH measurements were
molecules which owns a perfect coordination pocket by performed on a PHS-3C digital pH-meter (Mettler Toledo, Amer-
combining the rhodamine-B skeleton with 1-(2-hydroxyphenyl) ica). Images of HeLa cells were captured with a laser confocal
ethanone.
Herein, through introducing 1-(2-hydroxyphenyl)ethanone
microscope (Carl Zeiss LSM-700, Germany).
to the rhodamine-B derived skeleton, we designed and synthe-
sized the rst novel rhodamine-based probe by two simple steps
Synthesis of probe L
for the detection of Al3+ with high selectivity, good stability, The synthetic route of L is shown in Scheme 1. Rhodamine
perfect reversibility and no toxicity. With the limit of detection hydrazide 2 was obtained by the reaction of NH2NH2$H2O
of 1.63 ꢀ 10ꢁ7 M, the probe could be successfully utilized in (0.050 mmol, 2.0 equiv.) with rhodamine-B 1 (0.025 mmol, 1.0
HeLa cells for sensing trace amount of Al3+ because of its equiv.) in reuxed ethanol (50 mL) without further purica-
excellent cell permeability and no toxicity.
tion.19 Then the solution of rhodamine hydrazide 2 (0.025
mmol, 1.0 equiv.) and o-hydroxy acetophenone (0.100 mmol, 4.0
equiv.) in ethanol (20 mL) was heated to reux for 10 h and
monitored by TLC. Aer the completion of the reaction, the
mixture was evaporated to dryness and to the residue was added
water. The extraction by ethyl acetate (20 mL) from the water for
three times and further recrystallization from ethyl acetate
afforded the target probe. The probe L was obtained as white
solid in 91.7% yield. m.p. 170–172 ꢂC 1H NMR (400 MHz, CDCl3)
d: 1.15 (t, J ¼ 7.0 Hz, 12H), 2.31 (s, 3H), 3.32 (q, J ¼ 7.0 Hz, 8H),
6.30 (dd, J ¼ 8.9, 2.6 Hz, 2H), 6.40 (d, J ¼ 2.6 Hz, 2H), 6.57 (d, J ¼
8.9 Hz, 2H), 6.71–6.85 (m, 2H), 7.12–7.23 (m, 2H), 7.43–7.57 (m,
3H), 7.87–8.01 (m, 1H), 11.76 (s, 1H) ppm; 13C NMR (100 MHz,
CDCl3) d: 12.6, 17.7, 44.4, 67.1, 98.2, 105.3, 108.1, 117.9, 118.1,
119.2, 123.2, 124.2, 128.2, 128.3, 129.0, 130.1, 132.1, 132.8,
148.9, 151.7, 153.5, 160.2, 161.6, 173.5 ppm. HRESIMS m/z:
Experimental section
Materials and methods
Deionized water was used throughout the experiment. All the
reagents were purchased from commercial suppliers and
utilized without further purication. All samples were prepared
at room temperature, shaken for 10 s before UV-vis and uo-
rescence detection. The solutions of metal ions were prepared
from Al(NO3)3$9H2O, Ba(NO3)2, Ca(NO3)2$4H2O, Co(NO3)2$6H2O,
CsNO3, Cu(NO3)2$3H2O, Fe(NO3)3$9H2O, Hg(NO3)2, KNO3,
LiNO3, Mg(NO3)2$6H2O, Mn(NO3)2, NaNO3, Ni(NO3)2$6H2O,
Zn(NO3)2$6H2O, respectively, and were dissolved in distilled
water. Thin-layer chromatography (TLC) was conducted on silica
gel 60F254 plate. All reactions were monitored by TLC with UV
indicator (Shanghai Jiapeng Technology Co. Ltd., China).
+
calcd for [M + H]+ C36H39N4O3 : 575.3017, found: 575.3009.
HEPES
(4-(2-hydroxyethyl)-1-piperzazineethanesilfonicacid)
buffer solutions (pH 7.2) were prepared using 20 mM HEPES,
and dened amount of aqueous sodium hydroxide under
adjustment by a pH meter. Britton–Robinson (B–R) buffers
were mixed by 40 mM acetic acid, boric acid, and phosphoric acid.
Dilute hydrochloric acid or sodium hydroxide was used for tuning
Preparation of probe solution
The mixture of 1 mL probe L at 100 mM in EtOH, 2.6 mL EtOH
and 0.4 mL HEPES gave 4.0 mL probe L at 25 mM for UV, uo-
rescence detection and cell imaging. For the detection of the pH
effect on the probe, 1.0 mL 100 mM probe L, 0.8 mL EtOH, 0.2
mL HEPES and 2.0 mL B–R buffers at the corresponding pH
were used to give the 4.0 mL probe solution.
1
pH values. H NMR and 13C NMR spectra (at 400 MHz and 100
MHz, respectively) were recorded on a Bruker Avance 400 FT
HeLa cell culture and imaging
HeLa cells were cultured in Dulbecco's modied Eagle's
medium (DMEM, Gibco) containing 10% calf bovine serum 50
(HyClone) at 37 ꢂC in humidied air and 5% CO2. The cells
were subcultured at 90% conuence with 0.25% trypsin (w/v)
every 2–3 days. For uorescence, the cells were seeded into
10 mL centrifuge tube, and the experiments to assay Al3+ uptake
were undertaken in the tube supplemented with 50 mM, 100 mM
or 150 mM of Al(NO3)3 for 1 h respectively. Then the cells were
washed with PBS (Phosphate Buffer Saline) twice and incubated
with 10 mM probe L for 3 h. Aer being washed by PBS twice, the
HeLa cells were imaged under a laser confocal microscope.
Scheme 1 Synthesis of the probe L reagents and conditions: (a)
ethanol, reflux, 24 h; (b) ethanol, reflux, 10 h.
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Cytotoxicity assay
The cells were seeded in 96-well plates at an initial density of
6000 cells per well, with 0.1 mL medium per well. Aer incu-
bation for 12 h, HeLa cells were treated with probe L (5, 10, 15
and 15 mM). The MTT assay was used to detect cell cytotoxicity.
Briey, cells were incubated for 4 h with the tetrazolium salt (3-
(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium enbro-
mide) with a nal concentration of 500 mg mLꢁ1, and meta-
bolically active cells reduced the dye to purple formazan. Dark
blue crystals were dissolved with 150 mL DMSO. The absorbance
of the DMSO solution was measured with a BIO RAD microplate
reader (model360, Hercules, California USA) at 490 nm.
Fig. 1 Fluorescence spectra of 25 mM L in buffered EtOH/HEPES (9 : 1,
v/v, pH 7.2) solution with 20 equiv. of metal ions. The inset showed the
fluorescence color of L with Al3+ (left) and only L (right) (excitation
wavelength: lex ¼ 560 nm; slit width, 10 nm; lem ¼ 578 nm, slit width,
5 nm).
Results and discussion
Synthesis and structural characterization
The reaction of NH2NH2$H2O and rhodamine-B 1 in ethanol
afforded rhodamine hydrazide 2, which then underwent a
condensation with o-hydroxyacetophenone in reuxing ethanol,
giving the target molecule 3, i.e. L (Scheme 1). Furthermore, the
wavelength of 560 nm, based on optically matching solutions of
rhodamine B standard (F ¼ 0.69 in ethanol).
1
structure of the target molecule L was determined by H NMR,
Then the titration experiment was performed in buffered
solution by adding Al3+ (0–50 equiv.) into 25 mM of probe L and
the results were presented in Fig. 3. The uorescence emission
intensity increased gradually upon the addition of Al3+ and
enhanced dramatically about 43-fold when 10 equiv. Al3+ was
added. When more Al3+ was titrated, instead of increasing
signicantly, the uorescence intensity presented as a faint
variation. The detection limit, based on the denition by IUPAC
(DL ¼ 3Sb/Cm; Sb: the range of detection result; C: coefficient of
range; m: the slope of the tted curve), acquired from the linear
of response range covering the Al3+ concentration from 0 to 2.5
ꢀ 10ꢁ5 Mꢁ1, was calculated to be 1.63 ꢀ 10ꢁ7 Mꢁ1 (Fig. S3†).
Besides, on the basement of linear tting of Benesi–Hide-
rand plot of Al3+ (1–9 equiv.) (Fig. S4†) with correlation coeffi-
cient over 0.99, the binding mode was recognized as 2 : 1
binding stoichiometry of L and Al3+, which was further
conrmed by Job's plot (Fig. S5†). In addition, the binding
13C NMR and HRMS.
Colorimetric recognition
The absorption response of L (25 mM) toward a variety of metal
ions was initially detected in EtOH/HEPES (9 : 1, v/v, pH 7.2)
solution in the presence of 20 equiv. of different metal ions and
the results were presented in Fig. S1.† The probe L was colorless
and exhibited no scarcely absorption at 450–650 nm in this
buffer solution, in agreement with the previous report,34 sug-
gesting that the L existed as a sprirocycle-closed form. Whereas
upon adding 20 equiv. various metal ions, a new absorption
band centered at 560 nm was recognized among Cu2+, Fe3+, Ni2+
and Al3+, which indicated that the probe L has the ability to
sense these four metal ions by naked eyes.
Fluorescent recognition of Al3+
constant Ks was also calculated to be 1.17 ꢀ 106 Mꢁ1
.
Aiming at further exploring the possibility of L as an efficient
probe, uorescence spectra of L was examined on different
kinds of metal ions. Among the four metal ions which could
response in the colorimetric recognition, besides that the Fe3+
and L manifested a faint emission, only the purple solution of L
and Al3+ exhibited a very strong emission, however, other metal
ions did not induce any signicant uorescence enhancement
(Fig. 1), which suggested that the L might be an ideal probe for
sensing Al3+ by uorescence spectra. The uorescence reached
peak in the solution EtOH/HEPES (9 : 1, v/v, pH 7.2) (Fig. S2†).
Then in the optimized solution, competition experiments were
carried out by detecting the variation in uorescence intensity
at 578 nm upon 20 equiv. Al3+ ion to a solution of L and different
metal ions (20 equiv.) (Fig. 2). It could be noticed that besides
Cu2+ none of these metal ions exerted any interference on the
uorescence intensity, suggesting that the probe L possessed
the ability to sense Al3+ with high selectivity and efficiency.
Besides, the solution of the probe L and Al3+ had a quantum
Fig. 2 Fluorescence intensity changes of 25 mM L to 20 equiv. of
different metal ions in EtOH/HEPES (9 : 1, v/v, pH 7.2) buffered solution
(black bars), and the fluorescence intensity changes when 20 equiv.
Al3+ ion was added to the mixture of L (25 mM) and 20 equiv. different
metal ions in the buffered solution, respectively (red bars). lex ¼ 560
yield of 0.29 in EtOH/HEPES (9 : 1, v/v, pH 7.2) at an excitation nm, lem ¼ 578 nm.
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Fig. 5 The plausible reaction mechanism of L and Al3+
.
Fig. 3 Fluorescence response of L (25 mM) in buffered EtOH/HEPES
(9 : 1, v/v, pH 7.2) solution on the addition of Al3+ (0–10 equiv.). lex
560 nm, lem ¼ 578 nm.
¼
We then investigated on the specic binding structure of L
and Al3+ with the assistance of 1H NMR and 13C NMR spec-
troscopy. In detail, interestingly, upon the addition of Al3+, the
sharp peak at 11.73 ppm (for the OH proton) was reduced and a
new peak at 9.25 ppm could be found in 1H NMR spectra which
might attribute to the proton of the OH in the newly formed
complex and in the 13C NMR spectra the peak at 44.14 ppm (for
the carbon atom of CH3 near OH) converted to two peaks in the
13C NMR (Fig. 4). Based on the previous articles38,39 and the
binding stoichiometry along with the alternations in the 1H
NMR and 13C NMR spectroscopy, the proposed reaction
mechanism of L and Al3+ was predicted in Fig. 5.
Fig. 6 Time dependence of fluorescence response of L (25 mM) in
buffered EtOH/HEPES (9 : 1, v/v, pH 7.2) solution with 20 equiv. Al3+
lex ¼ 560 nm, lem ¼ 578 nm.
.
We then explored the effect of time and pH value on the
probe L. To our delight, the curves (Fig. 6) of response time
revealed that L could form complex with 20 equiv. Al3+
completely within 1 min, aer which the uorescence intensity
remained constant in the following 30 min, indicating that the
complex thus formed possessed perfect stability. In terms of pH
effect, the uorescence intensity did not change signicantly as
pH converted from 4.88 to 8.53 (Fig. S6†), whereas a sudden
variation was observed when the pH was over 9.
Furthermore, to examine the reversibility of the binding of L
to Al3+, we used EDTA, a well-known metal ion chelator in
buffered EtOH/HEPES solutions. The uorescence intensity of
L–Al3+ (25 mM) at 578 nm was almost totally quenched by the
addition of 1.0 equiv. of EDTA (Fig. 7). Then the uorescence
intensity recovered with the addition of Al3+ to the mixture of L–
Al3+–EDTA (25 mM). It could be inferred that the selective
binding of L and Al3+ was easily reversible and L would perform
as a recycle probe in practical utilization.
Fluorescent imaging of intercellular Al3+
To investigate the potential application of probe L in living cells,
we performed the intercellular Al3+ imaging of HeLa cells by a
laser confocal microscope (Fig. 8). Aer incubation with 10 mM
of L for 1 h at 37 ꢂC, no obvious uorescence emission was
intracellular, which was in agreement with the property of the L
discovered in our previous study. However, when different
concentrations of Al3+ was added to the growth medium to
incubate HeLa cells for 1 h, the same treatment with L would
generate signicant intracellular uorescence. As with the
increasing Al3+ concentration in incubated cells, the intracel-
lular uorescence enhanced dramatically, indicating that dose-
dependent response of L to Al3+ could be applied in live cells as
well. Furthermore, contrary to the other Al3+ probes with poor
water solubility which were impermeable to the physiological
conditions, L could permeate into the HeLa cells within 1 h.
MTT toxicity assay
The toxicity of probe L in HeLa cells was assayed by MTT
method by the incubation of the cells with L at different
1
Fig. 4 Partial H NMR spectra of (a) probe L, (b) L in the presence of
Al3+. Partial 13C NMR spectra of (c) probe L, (d) L in the presence of Al3+
.
concentrations for 48
h
(Fig. 9). Even with the high
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Fig. 7 Reversibility of L–Al3+ binding (25 mM) in buffered EtOH/HEPES
(9 : 1, v/v, pH 7.2) solution. lex ¼ 560 nm, lem ¼ 578 nm.
Fig. 9 The viability of HeLa cells after incubation with different
concentrations of probe L for 24 h (the viability was tested by MTT
assay with n ¼ 5 replicates).
to cells and thus safely to be applied in cell marking and clinical
use in physiological conditions.
Conclusions
In summary, the rst rhodamine-based probe L for uorescent
recognition of Al3+ in living cells was designed and synthesized.
The uorescence intensity of the probe enhanced 43-fold and
the color of L in the buffer solution changed from colorless to
purple with the addition of Al3+. Probe L could serve as a uo-
rescent indicator for Al3+ without any inference from other
metal ions, at a wide pH ranging from 4.9 to 8.5. Besides, the
detection limit of L was 1.63 ꢀ 10ꢁ7 Mꢁ1 and L possessed
perfect stability and excellent reversibility. Finally, probe L has
been successfully applied to the imaging for sensing Al3+ in
HeLa cells in uorescence protocol and was proved to be non-
toxic to living cells by MTT assay.
Acknowledgements
We would like to thank the National Natural Science Founda-
tion of China (21002081) and the Fundamental Research Funds
for the Central Universities, P.R. China (XDJK2012B012) for
nancial support.
Fig. 8 (a) HeLa cells incubated with 10 mM probe for 1 h at 37 ꢂC (b)
HeLa cells incubated with 25 mM Al3+ added to the growth medium
for 1 h at 37 ꢂC and then incubated with 10 mM probe for 1 h. (c) HeLa
cells incubated with 50 mM Al3+ added to the growth medium for 1 h
at 37 ꢂC and then incubated with 10 mM probe for 1 h at 37 ꢂC. (d)
HeLa cells incubated with 75 mM Al3+ added to the growth medium
for 1 h at 37 ꢂC and then incubated with 10 mM probe for 1 h at 37 ꢂC.
(e) Bright-field view of panel (a). (f) Bright-field view of panel (b). (g)
Bright-field view of panel (c). (h) Bright-field view of panel (d). (i)
Overplay image of (a) and (e). (j) Overplay image of (b) and (f). (k)
Overplay image of (c) and (g). (l) Overplay image of (d) and (h). Scale
bars: all images ¼ 10 mm.
Notes and references
1 H. N. Kim, Z. Guo, W. Zhu, J. Yoon and H. Tian, Chem. Soc.
Rev., 2011, 40, 79–93.
2 H. N. Kim, W. X. Ren, J. S. Kim and J. Yoon, Chem. Soc. Rev.,
2012, 41, 3210–3244.
3 D. T. Quang and J. S. Kim, Chem. Rev., 2010, 110, 6280–6301.
4 J. S. Kim and D. T. Quang, Chem. Rev., 2007, 107, 3780–3799.
5 V. Luxami and S. Kumar, RSC Adv., 2012, 2, 8734–8740.
6 Z. Xu, N. J. Singh, J. Lim, J. Pan, H. N. Kim, S. Park, K. S. Kim
and J. Yoon, J. Am. Chem. Soc., 2009, 131, 15528–15533.
7 J. H. Jung, D. S. Cheon, F. Liu, K. B. Lee and T. S. Seo, Angew.
Chem., Int. Ed., 2010, 49, 5708–5711.
concentration at 20 mM, 2-fold higher than the general
concentration used in imaging experiment, the viability of HeLa
cells remained at 99.2 ꢃ 2.5%. Therefore, probe L was non-toxic
8 D. Knapton, M. Burnworth, S. J. Rowan and C. Weder, Angew.
Chem., Int. Ed., 2006, 45, 5825–5829.
5248 | RSC Adv., 2015, 5, 5244–5249
This journal is © The Royal Society of Chemistry 2015

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Paper
RSC Advances
9 R. C. Stringer, S. Gangopadhyay and S. A. Grant, Anal. Chem., 26 S. Sinha, R. R. Koner, S. Kumar, J. Mathew, P. V. Monisha,
2010, 82, 4015–4019. I. Kazi and S. Ghosh, RSC Adv., 2013, 3, 345–351.
10 T. Naddo, X. Yang, J. S. Moore and L. Zang, Sens. Actuators, B, 27 J. Y. Kwon, Y. J. Jang, Y. J. Lee, K. M. Kim, M. S. Seo, W. Nam
2008, 134, 287–291. and J. Yoon, J. Am. Chem. Soc., 2005, 127, 10107–10111.
11 B. Sun, W. Xie, G. Yi, D. Chen, Y. Zhou and J. Cheng, J. 28 Y.-K. Yang, K.-J. Yook and J. Tae, J. Am. Chem. Soc., 2005, 127,
Immunol. Methods, 2001, 249, 85–89. 16760–16761.
12 M. de la Guardia, A. R. Mauri and C. Mongay, J. Anal. At. 29 V. Dujols, F. Ford and A. W. Czarnik, J. Am. Chem. Soc., 1997,
Spectrom., 1988, 3, 1035–1038. 119, 7386–7387.
13 W. J. McShane, R. S. Pappas, V. Wilson-McElprang and 30 M. Vendrell, D. Zhai, J. C. Er and Y. T. Chang, Chem. Rev.,
D. Paschal, Spectrochim. Acta, Part B, 2008, 63, 638–644.
14 R. B. Martin, Acc. Chem. Res., 1994, 27, 204–210.
15 E. Delhaize and P. R. Ryan, Plant Physiol., 1995, 107, 315–
321.
16 M. Venturini-Soriano and G. Berthon, J. Inorg. Biochem.,
2001, 85, 143–154.
2012, 112, 4391–4420.
31 H. N. Kim, M. H. Lee, H. J. Kim, J. S. Kim and J. Yoon, Chem.
Soc. Rev., 2008, 37, 1465–1472.
32 A. Chatterjee, M. Santra, N. Won, S. Kim, J. K. Kim, S. B. Kim
and K. H. Ahn, J. Am. Chem. Soc., 2009, 131, 2040–2041.
33 Y. Xiang, A. Tong, P. Jin and Y. Ju, Org. Lett., 2006, 8, 2863–
2866.
17 R. J. P. Williams, Coord. Chem. Rev., 2002, 228, 93–96.
18 S. Mazzaferro, I. Perruzza, S. Costantini, M. Pasquali, 34 W. Y. Liu, S. L. Shen, H. Y. Li, J. Y. Miao and B. X. Zhao, Anal.
L. Onorato, D. Sardella, R. Giordano, L. Ciaralli, Chim. Acta, 2013, 791, 65–71.
P. Ballanti, E. Bonucci, G. A. Cinotti and G. Coen, Nephrol., 35 F. Ge, H. Ye, J.-Z. Luo, S. Wang, Y.-J. Sun, B.-X. Zhao and
Dial., Transplant., 1997, 12, 2679–2682. J.-Y. Miao, Sens. Actuators, B, 2013, 181, 215–220.
19 P. F. Good, C. W. Olanow and D. P. Perl, Brain Res., 1992, 593, 36 H. Ye, F. Ge, X.-C. Chen, Y. Li, H. Zhang, B.-X. Zhao and
343–346. J.-Y. Miao, Sens. Actuators, B, 2013, 182, 273–279.
20 J. Barcelo and C. Poschenrieder, Environ. Exp. Bot., 2002, 48, 37 H. Yang, Z. Zhou, K. Huang, M. Yu, F. Li, T. Yi and C. Huang,
75–92. Org. Lett., 2007, 9, 4729–4732.
21 K. Soroka, R. S. Vithanage, D. A. Phillips, B. Walker and 38 K. Huang, H. Yang, Z. Zhou, M. Yu, F. Li, X. Gao, T. Yi and
P. K. Dasgupta, Anal. Chem., 1987, 59, 629–636. C. Huang, Org. Lett., 2008, 10, 2557–2560.
22 Y. Zhao, Z. Lin, H. Liao, C. Duan and Q. Meng, Inorg. Chem. 39 M. Li, H.-S. Lv, J.-Z. Luo, J.-Y. Miao and B.-X. Zhao, Sens.
Commun., 2006, 9, 966–968. Actuators, B, 2013, 188, 1235–1240.
23 C. Gou, S.-H. Qin, H.-Q. Wu, Y. Wang, J. Luo and X.-Y. Liu, 40 W.-Y. Liu, H.-Y. Li, H.-S. Lv, B.-X. Zhao and J.-Y. Miao,
Inorg. Chem. Commun., 2011, 14, 1622–1625. Spectrochim. Acta, Part A, 2012, 95, 658–663.
24 S. M. Ng and R. Narayanaswamy, Anal. Bioanal. Chem., 2006, 41 W.-Y. Liu, H.-Y. Li, B.-X. Zhao and J.-Y. Miao, Org. Biomol.
´
386, 1235–1244.
Chem., 2011, 9, 4802–4805.
25 D. Maity and T. Govindaraju, Chem. Commun., 2010, 46,
4499–4501.
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