An ATP-selective, lanthanide complex luminescent probe

Article abstract of DOI:10.1039/c3dt50986a

A luminescent probe based on a europium complex is developed, which effectively distinguishes adenosine-5′-triphosphate (ATP) from adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in pure water at pH 6.8. With a longer lifetime (in ms range), the probe is prospectively applied to biological systems to monitor ATP levels by completely removing the background fluorescence of other molecules. The Royal Society of Chemistry 2013.

Full text of DOI:10.1039/c3dt50986a

Dalton
Transactions
View Article Online
View Journal | View Issue
PAPER
An ATP-selective, lanthanide complex luminescent
probe†
Cite this: Dalton Trans., 2013, 42, 9840
Xiao Liu, Jun Xu, Yinyun Lv, Wenyu Wu, Weisheng Liu and Yu Tang*
Received 15th April 2013,
Accepted 3rd May 2013
A luminescent probe based on a europium complex is developed, which effectively distinguishes adeno-
sine-5’-triphosphate (ATP) from adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in
pure water at pH 6.8. With a longer lifetime (in ms range), the probe is prospectively applied to biological
systems to monitor ATP levels by completely removing the background fluorescence of other molecules.
DOI: 10.1039/c3dt50986a
www.rsc.org/dalton
europium and terbium center through synthesizing a series of
lanthanide complexes.13 In particular, the binding of carbon-
Introduction
Phosphates play a very important role in biological systems ate to cationic Eu complexes was monitored by variation in the
and everyday life. Among these, adenosine-5′-triphosphate emission intensity, ratio of intensities (615/594 nm), and dis-
(ATP) is one of the most studied molecules in biological symmetry factors as a function of added total carbonate. Four
science due to its energy production and storage functions in years later, their group investigated the selectivity in the
living cells. ATP is involved in energy metabolism, DNA replica- binding of phosphorylated tyrosine residues to the lanthanide
tion and transcription, and other fundamental activities of complexes with heptadentate ligation by the changes in the
life.1 Consequently, the real-time monitoring of ATP levels is luminescence emission spectra and 1H NMR spectroscopy.14
essential for the study of multiple cellular mechanisms, And then they researched into the chemoselective binding of
enzyme activity, and other activities involving the production O-phosphono-L-tyrosine residues to europium macrocyclic
and consumption of ATP.2 For the detection and quantifi- complexes by ratiometric changes in lanthanide-based emis-
cation of ATP, a variety of colorimetric and fluorescent probes sion and circularly polarized luminescence spectra.15
have been developed. The majority of these are based on acri-
Until now, there are rare examples of ATP probes based on
done,3 anthracene,4 coumarin,5 naphthalimide,6 pyrene,7 lanthanide complexes reported.17–24 In 2004, R. F. Ziessel et al.
xanthenes,8 other fluorescent dyes,9 and transition metal- designed a luminescent lanthanide complex with a marked
based complexes.8b,10
selectivity for HPO4 and ATP4−, and investigated the inter-
2−
Compared with the probes based on organic molecules and actions of these anions with the complex.20 Two years later,
transition metal-based complexes, lanthanide-based probes Otto S. Wolfbeis et al. found that the europium tetracycline
have many advantageous such as sharp line-like emission complex could be used as the probe of ATP, and studied the
bands, large Stokes shifts, and long lifetimes.11 The long lumi- applicability of this fluorescent probe to the determination of
nescence lifetimes, typically in the ms range, make lantha- kinase activity.21 More recently, the group of Pierre has
nide-based complexes fascinating and useful candidates for designed a molecular probe, Tb-DOTAm-Phen, for the direct
time-gated probes in biological systems as they typically time-gated detection of ATP based on the interactions includ-
remove the background fluorescence of other organic sub- ing the stacking and electrostatic interactions between the
stances.12 For the past few years, D. Parker’s group has develo- probe and ATP.22 The probe can be efficiently applied to the
ped some probes based on lanthanide complexes for anions systems with millimolar concentrations of ATP which are rele-
and studied the mechanism of interactions between the vant to intracellular conditions.
probes and anions.13–16 In 2000, they studied the selectivity of
On the basis of the prior works, we here present a lantha-
reversible oxy-anion binding in aqueous solution at a chiral nide-complex luminescent probe (probe 1) which exhibits high
selectivity for ATP, and can discriminate ATP from adenosine
diphosphate (ADP) and adenosine monophosphate (AMP) in
Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu
pure aqueous media of pH 6.8 (Scheme 1). This probe is a
europium complex from a derivative of cyclen (1,4,7,10-tetra-
Province, State Key Laboratory of Applied Organic Chemistry and College of
Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000,
azacyclododecane) with three acetamide arms coordinated to
P. R. China. E-mail: tangyu@lzu.edu.cn; Fax: (+86) 931-891-2582
europium and a fourth arm, a conjugated derivative of terpyri-
dine, that serves as an antenna. The three acetamide arms
†Electronic supplementary information (ESI)
available. See DOI:
10.1039/c3dt50986a
9840 | Dalton Trans., 2013, 42, 9840–9846
This journal is © The Royal Society of Chemistry 2013

View Article Online
Dalton Transactions
Paper
Scheme 1 Fluorescent sensing of ATP based on a europium complex probe
(probe 1).
stabilize the europium complex kinetically and thermodynami-
cally, thereby limiting influence by the aqueous solution,
while conferring a 3+ charge to the entire complex. The 3+
charged macrocyclic segments with the heptadentate ligation,
which is likely to be bound one or two water molecules, can
interact with the phosphates of ATP. The terpyridine arm
bearing the large conjugation group acts both as an antenna
and as a conjugate to the adenine base of ATP. In addition, the
length of the terpyridine arm chain of the cyclen ligand is an
important factor that influences the interactions of the com-
plexes with ATP. The length of the probe molecule was a key
principle considered in the process of designing the probe. It
was expected that the combination of the interaction between
the europium centre and the phospho group of ATP and the
π–π stacking between the terpyridine derivative and the
adenine base of ATP would present different luminescent
phenomena compared with other anions.22
Scheme 2 Synthesis of probe 1.
Synthesis of the ligand was initiated by first introducing the
terpyridine group into the cyclen, followed by addition of the
three acetamide arms. The lanthanide complex (probe 1) was
formed by adding the solution of Eu(NO3)3·6H2O to the solu-
1
tion of the ligand (Scheme 2). The H NMR of the ligand (see
Fig. S1 in the ESI†) and the mass spectrum of probe 1 (see
Fig. S2 in the ESI†) are reported in the ESI.†
Fig. 1 The pH dependence of the emission spectra of probe 1.
higher sensitivity than the ones with quenched luminescence,
all of the experiments on probe 1 were carried out at pH 6.8.
The luminescence emission changes of probe 1, by itself or
Results and discussion
Luminescence ATP-sensing with probe 1
following addition of F−, Cl−, Br−, I−, SO42−, S2−, HS−, HSO3
,
,
−
2−
SO32−, S2O32−, S2O82−, CO32−, NO2−, NO3−, H2PO4−, HPO4
PO43−, P2O74−, AMP, ADP, or ATP, are plotted in Fig. 2. The
luminescence intensity of probe 1 (the quantum yield, Φ =
1.75%) is enhanced by approximately 8.3-fold with the
addition of ATP, while the other anions produced negligible
responses. The probe not only distinguishes ATP from other
To investigate the influence of pH, the changes in the lumine-
scence intensity of probe 1 at 615 nm between pH 6.8–8.2 are
shown in Fig. 1. As the pH mounted up, the luminescence
intensity of probe 1 increased firstly and then decreased, with
maximum intensity being reached at pH ca. 7.3–7.4. The
enhanced luminescence between pH 6.8–7.4 could be attribu-
ted to the protonation of the terpyridine moiety, which could
impact the energy-transfer from the antenna to europium
ions.25 And then OH− might coordinate to Eu3+ between pH
7.4–8.2, which could quench the luminescence. In view of the
fact that the probes with enhanced luminescence may have
4
inorganic anions including H2PO4−, HPO42−, PO43−, and P2O7
−, but also discriminates ATP from ADP and AMP remarkably
well, which can be observed by the naked eye under an ultra-
violet lamp.
The luminescence changes of probe 1 following the con-
tinuous addition of ATP are seen in Fig. 3 and Fig. S3† (see
This journal is © The Royal Society of Chemistry 2013
Dalton Trans., 2013, 42, 9840–9846 | 9841

View Article Online
Paper
Dalton Transactions
Table 1 The lifetime data of probe 1 and probe 1 + ATP in water and deuter-
ated water
a
τ
H2O
(ms)
τ
D2O
(ms)
q
H2O
Probe 1
Probe 1 + ATP
0.55
0.52
1.64
2.29
0.88
1.21
a Values for q were calculated based on the method from D. Parker
et al.27
ATP.13,26 It is inferred that the phospho group of ATP has co-
ordinated to the europium centre.
The luminescence lifetime data of probe 1 with and
without the addition of ATP were measured to determine the
hydration number (q) of the water molecules coordinated to
Eu3+ in aqueous solution. The data of the luminescence time
(τ) determined in H2O and D2O were listed in Table 1.
Hydration numbers, q, were calculated using the following
eqn:
Fig. 2 Luminescence responses of probe 1 (50 μM) in the presence of various
anions (25 μM ATP, 25 μM ADP, 25 μM AMP and others 50 μM) in the pure
aqueous media at pH 6.8 (30 mM HEPES) with an excitation at 335 nm (exci-
tation slit width = 10 nm and emission slit width = 5 nm) (inset: probe 1 only,
and probe 1 with the addition of ATP, ADP, or AMP, observed under an ultra-
violet lamp at 365 nm).
ꢀ1
ꢀ1
q ¼ 1:2½τH O ꢀ τD O ꢀ 0:25 ꢀ 0:075nOvCNH
ꢁ
ð1Þ
2
2
where nOvCNH is the number of amide N–H oscillators in
which the amide carbonyl oxygen is coordinated to Eu3+.27
These data suggest that the europium centre of probe 1
binds one water molecule, and the bound water molecule
won’t be displaced when the probe 1 associated with ATP. The
europium centre still binds the phospho group of ATP whilst
retaining a bound water molecule.13,26
The conditional association constant20 for the formation of
the species with a 2 : 1 stoichiometry between probe 1 and ATP
during the enhanced luminescence titrations was calculated to
be 7.85 × 103 M−2, and the detection limit for ATP was 8.87 ×
10−6 M (see Fig. S4 in the ESI†). As shown in Fig. 4, the lumi-
nescence intensity of probe 1 with the addition of ATP
decreased continuously as the enhanced pH, with a rapid
decline between 7.4–7.8. It suggests that it has a potential
application for pH determination in the range between
7.4–7.8.
Fig. 3 Enhanced luminescence titrations of probe 1 with ATP in the pure
aqueous media at pH 6.8 (30 mM HEPES) with an excitation at 335 nm (exci-
tation slit width = 10 nm and emission slit width = 5 nm).
In order to investigate the possibility of applying the probe
to the bio-fluids and biological systems, competition exper-
iments were carried out (Fig. 5). The experiments with 20 mM
2−
−
CO3 or HCO3 were performed at pH 7.4, and the experi-
Fig. S3 in the ESI†). The fluorescence titration shows that the ments with 0.13 mM citrate or 0.1 mM other anions were all
luminescence intensity of probe 1 increased progressively with achieved at pH 6.8. Other phosphate anions appeared to have
continuous addition of ATP, and the binding stoichiometry some influence on the selectivity of probe 1 for ATP, possibly
between probe 1 and ATP was calculated at 2 : 1 at peak lumi- by competing with the ATP phosphate. Also, citrate3− impacted
nescence intensity (the quantum yield, Φ = 4.69%). The struc- the selectivity of probe 1 for ATP because the 3+ charged
ture suggested by these data likely involves a single ATP complex with heptadentate ligation had high affinity to the
molecule bound between two probe 1 molecules, resulting in highly charged anions, especially if they were sterically
the observed luminescence. As shown in Fig. 3, the intensity demanding.16 In addition, the selectivity was also influenced
2−
−
2−
ratio of the bands at 615 nm to 591 nm in the emission by CO3 and HCO3 at pH 7.4, and the influence of CO3
spectra changed gradually with the continuous addition of was more serious than HCO3−. The sandwich-like structure is
ATP. The value of the intensity ratio of the bands at 615/ likely formed due to the coordinated interactions between
591 nm changed from 2.5 at the beginning to 1.3 in the end, Eu3+ and the phosphate component of ATP, as well as π–π
which indicated that the coordination environment of euro- stacking interactions between the antenna terpyridine group
pium ions of probe 1 has been changed with the addition of and the adenine base of ATP.
9842 | Dalton Trans., 2013, 42, 9840–9846
This journal is © The Royal Society of Chemistry 2013

View Article Online
Dalton Transactions
Paper
Fig. 6 Quenched luminescence titrations of probe 1 with ATP in the pure
aqueous media at pH 6.8 (30 mM HEPES) with an excitation at 335 nm (exci-
tation slit width = 10 nm and emission slit width = 5 nm).
Fig. 4 The pH dependence of the emission spectra of probe 1 with the
addition of ATP.
ATP and transferred from ATP molecules and with the
obviously nonradiative transitions weakened.28 The adaptive
length of the arm chain of the ligand and the combination of
interactions between probe 1 and ATP are believed to be
sufficient to differentiate ATP from ADP and AMP.22
During luminescence titrations, the luminescence intensity
reached a maximum when the ATP concentration was half that
of probe 1, following which a steady decline in luminescence
was observed with continued addition of ATP (Fig. 6). These
data suggest that the sandwich-like structure formed by probe
1 and ATP at a 2 : 1 ratio is gradually modified with the con-
tinuous addition of ATP, forming a new structure with a 1 : 1
stoichiometry between probe 1 and ATP (Scheme 3). This latter
structure (the quantum yield, Φ = 4.89%) would include fewer
conjugated planes and weaker rigidity than the original struc-
ture, thereby producing less luminescence intensity. In spite of
Fig. 5 Competition experiments. The black bars represent the solutions of
probe 1 (0.05 mM) with the addition of an excess of anions, and the red bars
represent the solution mentioned above with the sequential addition of
0.025 mM ATP. a, blank; b, F−; c, Cl−; d, Br−; e, I−; f, CO32−; g, HS−; h, S2−
;
;
−
i, HSO3−; j, SO32−; k, SO42−; l, S2O32−; m, S2O82−; n, NO2−; o, NO3−; p, H2PO4
q, HPO42−; r, PO43−; s, P2O74−; t, ADP; u, AMP; v, citrate3−; w, CO32−; x, HCO3
.
−
The concentrations of these anions represented by the letters from a to u were
all 0.1 mM, and the competition experiments were carried out at pH 6.8. The
concentration of citrate3− was 0.13 mM, and the competition experiments were
2−
−
carried out at pH 6.8. The concentrations of CO3 and HCO3 were all 20 mM,
and the competition experiments were carried out at pH 7.4.
Mechanism of response
The proposed mechanism of luminescence enhancement is
described as follows: (1) the length of the terpyridine arm
chain of the ligand fits for ATP to realize the coordinated inter-
actions and the π–π stacking interactions with the probe; (2)
the π–π stacking interactions between the terpyridine group of
the ligand and ATP could strengthen the rigidity of the conju-
gate planes of the antenna groups and restrict the rotations of
C–C bonds between the aromatic rings. Thus the ligands
Scheme 3 The proposed mechanism for ATP sensing based on probe 1 (inset:
probe 1 only, and probe 1 with the addition of 0.25 eq., 0.50 eq., 1.0 eq.,
improve the Eu3+ sensitization with the energy absorbed by 2.0 eq. of ATP, respectively, observed under an ultraviolet lamp at 365 nm).
This journal is © The Royal Society of Chemistry 2013
Dalton Trans., 2013, 42, 9840–9846 | 9843

View Article Online
Paper
Dalton Transactions
coordinating with one adenosine nucleotide, the complex monophosphate sodium was purchased from Acros Organics
would remain positively-charged and would thus exhibit some Company. Europium nitrate (Eu(NO3)3·6H2O) was obtained by
affinity for the negatively-charged adenosine nucleotide, while dissolving Eu2O3 (99.99%, Shanghai Yuelong) in nitric acid fol-
the conjugated group would still align to produce π–π stacking lowed by successive fuming to remove excess acid. The other
even at the 1 : 1 stoichiometry. The luminescence intensity at chemicals were all commercially available. All of the chemicals
1 : 2 stoichiometry between probe 1 and ATP (the quantum were used as received. Deionized water was used to prepare all
yield, Φ = 2.82%) decreases very slowly with the continuous aqueous solutions. The anions used in the fluorescence experi-
addition of ATP. During the quenched luminescence titrations ments were all sodium salts. All measurements were repeated
of probe 1 with ATP, the values of the intensity ratio of the three times, and the general average was obtained.
bands at 615/591 nm stay at 1.4 0.1. It indicates that the
Syntheses
coordination environment of europium ions has not been
changed. At the same time, it suggests that the following π–π
stacking from the excess of ATP does not change the coordi- chloride (9.0 g, 80 mmol) was added dropwise to aqueous
Synthesis of 2-chloro-N-methylacetamide.29 2-Chloroacetyl
nation environment of europium ions.
methylamine (40%, 6.2 g, 80 mmol) in 60 mL of water at
−20 °C with stirring magnetically. The temperature rose to
0 °C slowly, and was controlled at 0 °C with stirring until the
reaction didn’t release heat any more. The hydrochloric acid
(36%–38%, 0.5 mL) was added to the solution, and then the
resulting solution was extracted with dichloromethane (4 ×
50 mL). The organic layer was washed with water (3 × 50 mL),
dried with anhydrous sodium sulfate, filtrated, and then spin-
evaporated in vacuo to give a clear liquid residue. The residue
was diluted with pentane (60 mL) and spin-evaporated in vacuo
to give a white solid (2.3 g, 26.7% yield). 1H NMR (CDCl3,
400 MHz) δ (ppm): 2.90 (d, 3 H), 4.07 (s, 2 H), 6.61 (s, 1 H).
MS: m/z = 108.2, 110.2 [M + H]+, m/z = 130.2, 132.2 [M + Na]+.
Synthesis of 2.30 Under magnetic stirring, 2-acetylpyridine
(4.84 g, 40 mmol) and 4-methylbenzaldehyde (2.40 g,
20 mmol) were added into ethanol (100 mL), and then NaOH
(1.60 g, 40 mmol) and ammonia water (25%–28%, 65 mL) were
added into the solution. The solution was stirred at 34 °C for
24 h. The mixture was cooled to the room temperature. The
off-white solid was obtained by filtration, washed with cold
ethanol (10 mL), and then dried at 55 °C under vacuum. The
white crystalline solid was obtained by crystallization from
ethanol, and then dried at 55 °C under vacuum (4.0 g, 62%
yield). 1H NMR (CDCl3, 300 MHz) δ (ppm): 2.42 (s, 3 H),
7.29–7.35 (m, 4 H), 7.80–7.89 (m, 4 H), 8.66 (d, 2 H), 8.71–8.73
(m, 4 H). 13C NMR (CDCl3, 75 MHz) δ (ppm): 156.3, 155.8,
150.1, 149.1, 139.0, 136.8, 135.5, 129.6, 127.1, 123.7, 121.3,
118.6, 21.25. MS: m/z = 324.3 [M + H]+.
Conclusions
In conclusion, we have developed a new europium-based probe
with high selectivity to ATP over ADP and AMP in pure
aqueous solution at pH 6.8. With the advantages cited for
lanthanides, this probe is a promising candidate for the detec-
tion of ATP and for monitoring activities involving the pro-
duction or consumption of ATP in biological systems. This
work provides a method for developing lanthanide probes with
high specificity and sensitivity for biological molecules.
Experiment section
Instrumentation
1H NMR and 13C NMR spectra were recorded on a Bruker
300 MHz and a Bruker 400 MHz spectrometer respectively.
Chemical shifts (δ) are given in parts per million (ppm). Mass
spectra were obtained on a Bruker esquire 6000 and a Bruker
maxis 4G respectively. Steady state luminescence spectra were
measured on
a Hitachi F-4500 fluorescence spectropho-
tometer, and the luminescence emission spectra on the pH
dependence were measured on a Shimadzu RF-5301 PC spec-
trofluorophotometer. The luminescence lifetime data were
determined by an absolute method on an Edinburgh Instru-
ment FLS920 fluorescence spectrophotometer. Quantum yields
were determined by an absolute method using an integrating
sphere on Edinburgh Instrument FLS920. The overall
quantum yields Φ measured were determined by an absolute
method using an integrating sphere (150 mm diameter, BaSO4
coating) with three measurements carried out for each sample.
The pH measurements were performed with a METTLER
TOLEDO EL20 pH-meter.
Synthesis of 3.30 2 (3.23 g, 10 mmol) was dissolved in CCl4
(40 mL), and then N-bromosuccinimide (NBS, 1.96 g,
12 mmol) and α,α-azoisobutyronitrile (AIBN, 0.130 g,
0.80 mmol) were added into the solution in order. The mixture
was stirred magnetically and refluxed for 2 h. Then the
mixture was cooled to room temperature. The succinimide was
removed by filtration and the solvent was evaporated under
vacuum. The crude product was crystallized from ethanol to
afford the pure light-yellow solid. The pure solid was dried at
60 °C under vacuum (2.06 g, 51% yield). 1H NMR (CDCl3,
Chemicals
2-Chloroacetyl chloride, 2-acetylpyridine, 4-methylbenzalde- 300 MHz) δ (ppm): 4.55 (s, 2 H), 7.33 (dd, 2 H), 7.53 (d, 2 H),
hyde, and cyclen (1,4,7,10-tetraazacyclododecane) were pur- 7.88 (m, 4 H), 8.65 (d, 2 H), 8.71 (m, 4 H). MS: m/z = 402.4,
chased from J&K Scientific Ltd. Adenosine-5′-triphosphate 404.4 [M + H]+.
disodium salt (ATP) and adenosine-5′-diphosphate disodium
salt (ADP) were purchased from Alfa Aesar. Adenosine-5′- CHCl3 (10 mL) was added dropwise to a solution of cyclen
Synthesis of 4.31 The solution of 3 (0.402 g, 1.0 mmol) in
9844 | Dalton Trans., 2013, 42, 9840–9846
This journal is © The Royal Society of Chemistry 2013

View Article Online
Dalton Transactions
Paper
(0.688 g, 4.0 mmol) in CHCl3 (100 mL) in 20 minutes. The
mixture was stirred at 30 °C for 10 hours, and then filtrated.
The organic layer was washed with saturated brine for five
times (5 × 100 mL), dried with anhydrous sodium sulfate, fil-
trated, and then spin-evaporated under vacuum to yield a light
yellow solid without purification. The product was used in the
next reaction directly.
4 (a) P. P. Neelakandan, M. Hariharan and D. Ramaiah, Org.
Lett., 2005, 7, 5765; (b) H. N. Kim, J. H. Moon, S. K. Kim,
J. Y. Kwon, Y. J. Jang, J. Y. Lee and J. Yoon, J. Org. Chem.,
2011, 76, 3805.
5 (a) Y. Kurishita, T. Kohira, A. Ojida and I. Hamachi, J. Am.
Chem. Soc., 2010, 132, 13290; (b) S. Mizukami, T. Nagano,
Y. Urano, A. Odani and K. Kikuchi, J. Am. Chem. Soc., 2002,
124, 3920.
Synthesis of 5.32 4 (0.2296 g, 0.460 mmol), 2-chloro-N-
methylacetamide (0.165 g, 1.54 mmol), and K2CO3 (0.212 g,
1.54 mmol) were added to 16 mL of anhydrous acetonitrile.
The mixture was stirred at 65 °C for 3 days under argon. The
resulting mixture was filtrated to remove the undissolved sub-
stance, and the solvent was removed under reduced pressure.
Purification was achieved by alumina column chromatography
using a gradient elution 100% CH2Cl2 to 95% CH2Cl2–5%
CH3OH. The product was obtained as a pale yellow solid
(0.0318 g, 9.8% yield). 1H NMR (CDCl3, 400 MHz) δ (ppm):
2.56–2.84 (m, 24 H), 3.08–3.10 (m, 5 H), 3.72 (s, 2 H), 7.35–7.38
(m, 4 H), 7.85–7.91 (m, 4 H), 8.67–8.73 (m, 6 H). MS: m/z =
707.6 [M + H]+.
6 A. J. Moro, P. J. Cywinski, S. Korstena and G. J. Mohr,
Chem. Commun., 2010, 46, 1085.
7 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.
8 (a) A. Ojida, I. Takashima, T. Kohira, H. Nonaka and
I. Hamachi, J. Am. Chem. Soc., 2008, 130, 12095;
(b) A. Ojida, H. Nonaka, Y. Miyahara, S. Tamaru, K. Sada
and I. Hamachi, Angew. Chem., Int. Ed., 2006, 45, 5518.
9 (a) F. Sancenón, A. B. Descalzo, R. M. Mánñez,
M. A. Miranda and J. Soto, Angew. Chem., Int. Ed., 2001, 40,
2640; (b) P. Mahato, A. Ghosh, S. K. Mishra, A. Shrivastav,
S. Mishra and A. Das, Chem. Commun., 2010, 46, 9134;
(c) C. Li, M. Numata, M. Takeuchi and S. Shinkai, Angew.
Chem., Int. Ed., 2005, 44, 6371.
Synthesis of probe 1. 5 (35.3 mg, 50 mmol) and Eu-
(NO3)3·6H2O (22.3 mg, 50 mmol) were dissolved in the same
solution of CHCl3 (3 mL) and ethyl acetate (3 mL) respectively. 10 A. S. Rao, D. Kim, H. Nam, H. Jo, K. H. Kim, C. Ban and
With stirring magnetically, the former solution and the latter K. H. Ahn, Chem. Commun., 2012, 48, 3206.
solution were filtrated into one round bottom flask succes- 11 (a) N. Shao, J. Jin, G. Wang, Y. Zhang, R. Yang and J. Yuan,
sively. Then the mixture was stirred for 4 hours and centri-
fuged. The solid was washed with the solution of CHCl3 and
Chem. Commun., 2008, 1127; (b) K. Binnemans, Chem. Rev.,
2009, 109, 4283.
ethyl acetate (v/v = 1 : 1) for three times (3 × 10 mL). After 12 J.-C. G. Bünzli, Chem. Rev., 2010, 110, 2729.
drying at 55 °C, probe 1 was obtained (25.5 mg, 48.2% yield). 13 J. I. Bruce, R. S. Dickins, L. J. Govenlock, T. Gunnlaugsson,
MS: m/z = 460.66 [Eu·5 + NO3−]2+, m/z = 982.32 [Eu·5 +
S. Lopinski, M. P. Lowe, D. Parker, R. D. Peacock,
J. J. B. Perry, S. Aime and M. Botta, J. Am. Chem. Soc., 2000,
122, 9674.
2NO3−]+.
14 P. Atkinson, Y. Bretonniere and D. Parker, Chem. Commun.,
2004, 438.
15 P. Atkinson, Y. Bretonniere, D. Parker and G. Muller, Helv.
Chim. Acta, 2005, 88, 391.
Acknowledgements
This work was financially supported by the National Natural
Science Foundation of China (Nos. 20931003 and 21071068), 16 R. Pal, D. Parker and L. C. Costello, Org. Biomol. Chem.,
and the National Science Foundation for Fostering Talents in 2009, 7, 1525.
Basic Research of the National Natural Science Foundation of 17 S. J. Butler and D. Parker, Chem. Soc. Rev., 2013, 42, 1652.
China (No. J1103307).
18 A. E. Hargrove, S. Nieto, T. Z. Zhang, J. L. Sessler and
E. V. Anslyn, Chem. Rev., 2011, 111, 6603.
19 A. M. Alam, M. Kamruzzaman, S. H. Lee, Y. H. Kim,
H. J. Jo, S. H. Kim and S.-R. Park, J. Lumin., 2012, 132, 789.
20 S. Mameri, L. J. Charbonnière and R. F. Ziessel, Inorg.
Chem., 2004, 43, 1819.
21 M. Schaferling and O. S. Wolfbeis, Chem.–Eur. J., 2007, 13,
4342.
Notes and references
1 (a) X. Shen, G. Mizuguchi, A. Hamiche and C. Wu, Nature,
2000, 406, 541; (b) A. Kornberg, J. Biol. Chem., 1988, 263, 1.
2 (a) P. D. Beer and P. A. Gale, Angew. Chem., Int. Ed., 2001,
40, 486; (b) C. Spangler, M. Schaeferling and 22 E. A. Weitz, J. Y. Chang, A. H. Rosenfield and V. C. Pierre,
O. S. Wolfbeis, Microchim. Acta, 2008, 161, 1; (c) K. L. Chun, J. Am. Chem. Soc., 2012, 134, 16099.
Biochemistry, 1971, 10, 2838; (d) J. Hirose, H. Fujiwara, 23 F. Hou, X. Wang and C. Jiang, Anal. Sci., 2005, 21, 231.
T. Magarifuchi, Y. Iguti, H. Iwamoto, S. Kominami and 24 Y. Miao, J. Liu, F. Hou and C. Jiang, J. Lumin., 2005, 116,
K. Hiromi, Biochim. Biophys. Acta, Protein Struct. Mol.
Enzymol., 1996, 1296, 103.
3 (a) J. Kaur and P. Singh, Chem. Commun., 2011, 47, 4472;
67.
25 T. Gunnlaugsson, J. P. Leonard, K. Sénéchal and
A. J. Harte, J. Am. Chem. Soc., 2003, 125, 12062.
(b) A. Ojida, Y. Miyahara, J. Wongkongkatep, S. Tamaru, 26 M. Botta, S. Aime, A. Barge, G. Bobba, R. S. Dickins,
K. Sada and I. Hamachi, Chem.–Asian J., 2006, 1, 555.
D. Parker and E. Terreno, Chem.–Eur. J., 2003, 9, 2102.
This journal is © The Royal Society of Chemistry 2013
Dalton Trans., 2013, 42, 9840–9846 | 9845

View Article Online
Paper
Dalton Transactions
27 A. Beeby, I. M. Clarkson, R. S. Dickins, S. Faulkner, 31 (a) J. Massue, S. E. Plush, C. S. Bonnet, D. A. Moore and
D. Parker, L. Royle, A. S. de Sousa, J. A. G. Williams and
M. Woods, J. Chem. Soc., Perkin Trans. 2, 1999, 493.
28 L. N. Puntus, K. A. Lyssenko, I. S. Pekareva and J. G. Bünzli,
J. Phys. Chem. B, 2009, 113, 9265.
T. Gunnlaugsson, Tetrahedron Lett., 2007, 48, 8052;
(b) J. Du, X. Wang, M. Jia, T. Li, J. Mao and Z. Guo, Inorg.
Chem. Commun., 2008, 11, 999; (c) S. Comby, S. A. Tuck,
L. K. Truman, O. Kotova and T. Gunnlaugsson, Inorg.
Chem., 2012, 51, 10158.
29 D. L. Musso, F. R. Cochran, J. L. Kelley, E. W. McLean,
J. L. Selph, G. C. Rigdon, G. F. Orr, R. G. Davis, 32 (a) B. McMahon, P. Mauer, C. P. McCoy, T. C. Lee
B. R. Cooper, V. L. Styles, J. B. Thompson and W. R. Hall,
J. Med. Chem., 2003, 46, 399.
30 B. Tang, F. Yu, P. Li, L. Tong, X. Duan, T. Xie and X. Wang,
J. Am. Chem. Soc., 2009, 131, 3016.
and T. Gunnlaugsson, J. Am. Chem. Soc., 2009, 131,
17542; (b) T. Gunnlaugsson, A. J. Harte, J. P. Leonard
and M. Nieuwenhuyzen, Supramol. Chem., 2003, 15,
505.
9846 | Dalton Trans., 2013, 42, 9840–9846
This journal is © The Royal Society of Chemistry 2013