New Dopa-AIE Compound Used as Fluorescence Sensor Material: Specificity and Quantification for Cu(II)

Article abstract of DOI:10.1002/cjoc.201600689

As a paramagnetic metal ion, Cu(II) is challenging to be detected by conventional fluorescence sensor because of its unselective paramagnetic quenching effects on common fluorophores. By combining catechol with tetraphenylethene, a typical aggregation-ind

Full text of DOI:10.1002/cjoc.201600689

FULL PAPER
DOI: 10.1002/cjoc.201600689
New Dopa-AIE Compound Used as Fluorescence Sensor
Material: Specificity and Quantification for Cu(II)
Siwei Liu,*,a Jing Cheng,b and Jiarui Xua
a PCFM Lab and GDHPPC Lab, School of Chemistry, Sun Yat-sen University, Guangzhou,
Guangdong 510275, China
b Department of Materials Science and Engineering and Bioengineering, University of California,
Berkeley, CA 94702, U. S. A.
As a paramagnetic metal ion, Cu(II) is challenging to be detected by conventional fluorescence sensor because
of its unselective paramagnetic quenching effects on common fluorophores. By combining catechol with tetra-
phenylethene, a typical aggregation-induced emission (AIE) moiety, we have successfully synthesized a new kind
of catechol, the dopa-AIE compound. Due to the properties of AIE core, the catechol has the “turn on” mechanism
as a fluorescence chemosensor. Specifically, the new catechol has the unique detection selectivity on Cu(II) in solu-
tion. The fluorescence intensity has the maximum value when the molar ratio of the catechol to Cu(II) is 1∶1. Be-
fore and after this point, the fluorescence intensity shows a linear relationship with the copper ion concentration, in-
creasing or decreasing. Thus, the quantitative calculation for Cu(II) or the dopa-AIE compound could be done ac-
cording to this response process.
Keywords dopamines, biosensors, copper, fluorescence, redox
Introduction
Up to now, there are many reports on dopa and its
derivatives. Among them, many researches have been
done mainly using dopa as a “middle-tier”, and with the
aid of this layer, make further functionalization to fab-
ricate materials with a variety of special features, such
as bio-fouling surfaces, antibacterial materials, self-
repairing hydrogels, and so on.[6-11] Nevertheless, the
preparation of sensor materials using the dopa adhesion
properties to directly or indirectly detect/monitor metal
ions in literature is seldom reported.
It is well known that marine mussels can bind
strongly to almost any surface in any case by secretory
glue proteins. The presence of dopa (3,4-dihydroxy-
L-phenylalanine) in these proteins is vital to their adhe-
sive properties. Furthermore, the content of dopa in the
protein is very important in their adhesive properties
too.[1-4] It is generally believed that the dopa adhesion is
somehow related to the presence of pyrocatechol, which
could bind to metal ions or crosslink themselves under
specific conditions. However, the detailed bonding
mechanisms of dopa on various substrates are compli-
cated and remain unknown by far.
Dopa itself has multiple functional groups: amino,
carboxyl and pyrocatechol groups. It can combine with
＋
＋
＋
＋
many metal ions such as Fe3 , Co2 , Ni2 , Zn2 and
other metal ions[12-14] through complex, coordination or
The molecular structure of dopa is not very complex.
However, since it is an amino acid, the interaction be-
tween amino and carboxyl group often tends to make
the chemical modification inconvenient and not straight-
forward. Wilker and coworker’s work[5] suggested that
the adhesion could be realized by the simple catechol
group in poly[(3,4-dimethoxystyrene)-co-styrene] pol-
ymers. Compared to dopa, the catechol structure they
used is simpler and easier to combine with other func-
tional groups. Most importantly, it may still retain major
characteristics of dopa. So, sometimes we call some
catechols dopa because they have the adhesion property
like dopa.
other forms, and can also reduce some metal ions such
as Ag＋ and Au3 to metal nanoparticles.[15,16] Thus, the
＋
interaction of dopa with metal ions is of diversity and
specificity.
Govindaraju’s group[17] reported an amphiphilic
perylene diimide, a bimolecular analog of dopa, as a
reversible fluorescence switching probe for the detec-
＋
＋
tion of and sensing cationic surfactants of Fe3 /Cu2 in
aqueous media, respectively. The as-synthesized com-
＋
pound could serve as a fluorometric probe only for Fe3 /
＋
Cu2 by means of fluorescence switch off state due to
the formation of metallosupramolecular assemblies.
Interestingly, the authors mentioned that the metallo-
*
E-mail: liusiw@mail.sysu.edu.cn
Received October 18, 2016; accepted November 25, 2016; published online XXXX, 2017.
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/cjoc.201600689 or from the author.
Chin. J. Chem. 2017, XX, 1—6
© 2017 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
1

Liu, Cheng & Xu
FULL PAPER
supramolecular assemblies could be disassembled by
addition of diethylenetriamine pentaacetic acid. Park et
al. fabricated dopa-functionalized gold nanoparticles
of its unselective paramagnetic quenching effects on
common fluorophores. Therefore, the new kind of cate-
chol we designed and synthesized here should be of
(AuNPs/dopa) that could detect low concentrations of
great value in practical application because it has unique
＋
Mn2 in aqueous solution.[18] Probably this is because
＋
detection selectivity and quantification on Cu2 .
＋
of the binding forces between dopa and Mn2 ions,
which leads to the AuNPs/dopa closer together, de-
creasing the interparticle distance and aggregating it
with a change in color of colloidal solution from red to
Experimental
Synthesis of bis(3,4-dimethoxyphenyl)methanone (1)
purplish-blue. And the ratio of absorbance at 700－550
Anhydrous dichloromethane (25 mL) was put into a
100 mL round flask. After the solvent was bubbled with
argon for 20 min, veratrole (1.1 mL, 8.5 mmol) and
3,4-dimethoxybenzoyl chloride (2.0 g, 10 mmol) were
added. Then, aluminum chloride anhydrous (1.8 g,
13.44 mmol) was carefully added in multiple portions
slowly. After the mixture was bubbled with argon for
another 5 min, the reaction solution was then heated at
reflux in an oil bath for 2 h. After cooled down to room
temperature, the mixture was poured into acid ice water
(1 mol/L HCl, 20 mL) and stirred for 10 min. The or-
ganic phase was extracted by dichloromethane, washed
by water 3 times, and then dried by anhydrous sodium
sulfate. After removing dichloromethane, the final
product as white powder was obtained by recrystalliza-
＋
nm was linear against the concentration of Mn2 ions.
A fluorosensor, N-doped graphene quantum dots, was
synthesized by one-step solid-phase method with citric
acid as the C source and dopa as the N source.[19] The
＋
fluorescence chemosensor is specific for Hg2 , with a
＋
＋
detection limit of 8.6 nmol/L. Although the Pb2 , Cd2 ,
＋
＋
Cu2 and Ni2 ions could interfere with the selectivity
＋
for Hg2 detection, this issue could be circumvented by
using triethanolamine and hexametaphoshpate as the
chelating agents. Therefore, the quantum dots are suita-
＋
ble to detect Hg2 with high sensitivity and selectivity.
From the few reported sensor materials based on
dopa (catechol), such dopa-detectors are of highly ex-
ceptional selectivity and sensitivity, which is just the
thing for preparation of sensor material. Judging from
the detection mechanism, changes in fluorescence in-
tensity of the dopa-sensors are usually based on the
“turn off” mechanism. From the visual effect, however,
the “turn on” mechanism is of higher sensitivity, and
better than the “turn off” mechanism, since “turn off”
mechanism usually requires relatively high concentra-
tion at the time of initial inspection.
1
tion in ethanol with the yield of 70%. H NMR (400
MHz, CDCl3) δ: 7.50－7.40 (m, 4H), 6.95 (d, J＝6.94
Hz, 2H), 4.01 (s, 6H), 3.99 (s, 6H); 13C NMR (100 MHz,
CDCl3) δ: 56.30, 114.97, 123.44, 133.70, 149.65,
152.82. MS (m/z) calcd for 1: 302.3218, found
302.2017.
Synthesis of 4-(1-(3,4-dimethoxyphenyl)-2,2-diphe-
nylvinyl)-1,2-dimethoxybenzene (2)
To develop dopa based sensor materials with “turn
on” mechanism, we firstly combined catechol with
tetraphenylethene, a typical aggregation-induced emis-
sion (AIE) moiety, and successfully synthesized a new
dopa-AIE compound. Generally speaking, the aggrega-
tion of chromophore would cause quenching light emis-
sion.[20,21] However, in 2001, Tang’s group found an
opposite phenomenon that is the “aggregation-induced
emission”.[22] Therefore, the as-synthesized dopa-AIE
compound should be of “turn on” mechanism when
used as a fluorescence chemosensor, which is different
from the previously reported “turn off” sensor materials
based on dopa (catechol). Specifically, the dopa-AIE
Diphenylmethane (2.0 g) was dissolved in 15 mL of
THF. Then, n-butyl lithium (4.54 mL, 2.5 mol/L in
hexane) was slowly added to the solution at 0 ℃ in
argon atmosphere. After 40 min, compound 1 (3.424 g)
was added to the mixture in solid and the resulting mix-
ture was allowed to warm to room temperature and
stirred overnight. The reaction was quenched with satu-
rated aqueous ammonium chloride solution followed by
a standard aqueous workup, affording the crude alcohol
in nearly quantitative yield. Subsequently, the crude
alcohol was dissolved in toluene and refluxed in the
presence of a catalytic amount of p-toluenesulfonic acid
with an azeotropic removal of water using a Dean-Stark
trap to get the product. The final product was purified
by crystallization from a mixture of dichloromethane
compound we designed here has the unique detection
＋
selectivity on Cu2 in solution. As it is well known that
low concentration copper is an important substance for
＋
almost all kinds of life.[23] High level free Cu2 , howev-
1
and methanol with the yield of 90%. H NMR (400
er, is known to elicit toxicity to cells and may cause liv-
er or kidney damage while long-term exposure.[24] Some
serious neurodegenerative diseases were found to be
closely related to the copper metabolism disorders, such
as Alzheimer’s, Parkinson’s, Menkes, and so on.[25,26] So,
MHz, CDCl3) δ: 7.19－7.06 (m, 10H), 6.70－6.58 (m,
6H), 3.87 (s, 6H), 3.53 (s, 6H); 13C NMR (100 MHz,
CDCl3) δ: 56.26, 115.97, 123.44, 126.24, 133.70,
135.94, 146.30. MS (m/z) calcd for 1: 452.5409, found
452.1753.
both on-site/real-time detection and quantification of
＋
Cu2 ions are very important.[27-29] The bad news is that,
Synthesis of 4-(1-(3,4-dihydroxyphenyl)-2,2-diphe-
nylvinyl)benzene-1,2-diol (3)
＋
as a paramagnetic metal ion, Cu2 is challenging to
detect with conventional fluorescence sensors because
To a 50 mL round flask were added compound 2 (1
2
www.cjc.wiley-vch.de
© 2017 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2017, XX, 1—6

New Dopa-AIE Compound Used as Fluorescence Sensor Material
mmol, 453 mg) and 5 mL of anhydrous dichlorometh-
ane. Argon atmosphere was established and maintained.
The mixture was cooled in liquid nitrogen/ethyl acetate
bath (about 80 ℃) and boron tribromide (0.42 mL, 4.4
mmol) was added through a septum with use of a sy-
ringe. Then, the cold bath was removed and the mixture
was stirred for 30 min, poured into ice water, stirred for
another 30 min, saturated with salt, and extracted with
dichloromethane. The extract was dried by anhydrous
magnesium sulfate and concentrated. The yield of the
AIE property.
As for the structure of this compound, from another
angle, we can say that tetraphenylethene is attached to
two pyrocatechols. It is well known that many catechol
compounds have excellent coating performance like
dopa.[7] So we tested the film-forming property of this
new kind of catechol. The synthesized compound (10
mg) was dissolved into a mixture solution of 1 mL of
dimethyl sulfoxide and 9 mL of tris(hydroxymethyl)
＋
aminomethane hydrochloride buffer with Mg2 inside.
1
final product was 95%. H NMR (400 MHz, DMSO) δ:
Then the cleaned glass substrate was put in and the so-
lution was kept shaking for 24h for film-coating on a
shaking table. The color of the glass substrate changed
from colorless to pink/red, and the modified glass sub-
strates could glow under ultraviolet light. These indi-
cated that these glass substrates were coated successful-
ly by this compound (Figure 2). Another interesting
phenomenon is that when the compound’s suspension
(in water) was put aside overnight, on the glass wall
there would leave a uniform fluorescent coating (Figure
3). The formed coating is very stable. We have tried to
use water, ethanol, acetone, dichloromethane and tetra-
hydrofuran to clean the bottles, even aided by ultrasound;
however, the fluorescence coating has no apparent
change. As a comparison, under the same conditions, we
investigated the film-coating property of compound 2.
There is no fluorescence coating inside the bottle at all
after clean by water. Therefore, we speculate that the
two pyrocatechols are very vital for the film-forming
property, just like dopa. In other words, catechol groups
may keep its film-coating property when they are con-
nected to some other organic compounds. Because of
this, we could design and synthesize new functional
catechol-compounds with good film-coating property.
Nevertheless, the compound we synthesized here
with both AIE and filming forming property is not be-
yond our expectation. Much to our surprise is that the
compound has a unique fluorescence detection response
7.19－7.00 (m, 6H), 6.98－6.84 (m, 4H), 6.52－6.28
(m, 4H), 6.26－6.13 (m, 2H); 13C NMR (100 MHz,
DMSO) δ: 116.38, 118.64, 123.80, 126.50, 128.38,
132.26, 136.39, 145.26. MS (m/z): calcd for 3: 396.4346,
found 396.1356.
Results and Discussion
The synthetic routes of the catechol are shown in
Scheme 1. Compound 1 was synthesized according to
the literature[30] and verified by 1H NMR, 13C NMR and
MS. Tetraarylethylene, the compound 2, was synthe-
sized by a modified two-step reaction method reported
before.[31] By using a standard boron tribromide cleav-
age method, the designed dopa-AIE catechol, compound
3, was obtained by ether cleavage from compound 2.
Traditionally, most fluorescence compounds have
the properties of the so-called “aggregation-caused
quenching (ACQ)” of light emission in the aggregated
state because of the severe intermolecular interac-
tion.[20,21] The aggregation-induced emission (AIE)
molecules, on the other hand, are usually non-emissive
in dilute solutions, but they show strong light emission
in their aggregated state.[32,33,34] The molecular structure
we synthesized in this article can be divided into two
motifs: tetraphenylethene (the AIE core) and pyrocate-
chols (the dopa motif). Through investigation of the
compound’s florescent curves in THF/water mixture
solution, we found that the new compound has a typical
AIE property (Figure 1). By introduction of catechols
into tetraphenylethene, the compound still shows good
＋
to Cu2 in THF/water solution (under similar condi-
＋
tions, we have investigated many other ions such as Ca2 ,
＋
＋
＋
＋
＋
＋
＋
＋
Mg2 , Zn2 , Co2 , Ni2 , Hg2 , Mn2 , Fe2 and Fe3 ).
Scheme 1 Synthetic routes for the dopa-AIE catechol
O
O
O
O
O
O
O
O
O
O
CH2Cl2
AlCl3
Cl
+
1
HO
OH
OH
O
O
O
O
O
O
THF, 0oC
CH2Cl2, BBr3
-80 oC
p-toluenesulfonic acid
1
+
OH
reflux
n-butyllithium
HO
O
O
3
2
(the dopa-AIE catechol)
Chin. J. Chem. 2017, XX, 1—6
© 2017 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
3

Liu, Cheng & Xu
FULL PAPER
Figure 1 PL spectra of the catechol (3) in THF/water mixtures
with different water fractions. By increasing the water fractions in
the mixture, the intensity of the fluorescence is increased. The
inset picture is the catechol solution (or suspension) under 365
nm UV irradiation in different THF/water mixture from 30% to
100% content of water (from e to a). The curves of i to e are sim-
ilar to curve e.
Figure 3 The catechol could form a uniform coating on glass
bottle. In each photo, there are three bottles, the right one was a
new empty bottle, and the left one was filled with the compound’s
suspension overnight at the beginning. As a comparison, some of
the suspensions were transferred from the left to the middle one.
(A, B, C) The left bottle was washed by water assisted with ul-
trasound; (D, E) After ultrasonic washing by using ethanol and
acetone for 5 min respectively; (F, G) After ultrasonic washing by
using THF for 10 min.
Figure 2 The glass substrates were coated by the catechol in
buffer. After thoroughly cleaning by pure water, the modified
glass substrates cast a blue-green glow under UV light.
creased and decreased linearly with copper ion concen-
tration (Figure 4c). To make full use of this advantage,
in theory, we can figure out the exact concentration of
copper by measuring two or three different concentra-
tion of catechol solution, and vice versa. In addition, by
graphing the wavelength at maximum fluorescence in-
tensity against the addition number of copper ions, we
found that there is a blue shift, from 412 nm to 402 nm,
existing in these fluorescence spectra along with the
addition of copper ions (Figure 4d). It indicates that the
energy level structure of the catechol (or the formed
complex with copper) may have been changed because
of the copper ions. Besides, in the compound’s solution,
about 2 or 3 h after the addition of copper ions, the color
of the solution would change from colorless to brown,
and then formed dark precipitation overnight. We sepa-
rated the precipitation and found that the structure had
Due to the amphiphilic structure, the catechol has poor
solubility in pure water. The fluorescence detection ex-
periments were carried out in the mixture of THF/water
(6∶4, V∶V). In a cuvette containing 2.5 mL of the
catechol solution (0.5 mg/mL), 5 μL of CuCl2 solution
(20 mg/mL) were added successively. The fluorescence
spectra were recorded immediately after each addition
and well mixing (Figures 4a and 4b). At the beginning,
the total amount of catechol in the cuvette is 3.153 μmol
＋
and the amount of Cu2 in each 5 μL solution is 0.744
μmol. The molar ratio of pyrocatechol in the catechol to
＋
Cu2 is just 2∶1 after successive addition of CuCl2
solution 4.2 times (5 μL for each addition). The changes
can be clearly seen from its fluorescence spectra. The
fluorescence intensity increases along with the copper
ions addition. The fluorescence intensity reaches the
maximum value at the fifth addition of CuCl2 (Figure
4a). In the meantime, the ratio of pyrocatechol (two
1
not changed as verified by H NMR and mass spec-
trometer, with the same peaks as the original compound.
We speculate that when copper ions were added to the
catechol solution, they would form an unstable network
structure, rather than a stable complex.
To investigate the oxidation states of copper after
addition to the catechol solution, we measured its XPS
such groups in one catechol molecular) in the compound
＋
to Cu2 is approximately 2∶1 (the ratio just for 2∶1
when adding 4.2 times of CuCl2). Since then, the fluo-
rescence intensity decreases with further addition of
CuCl2 (Figure 4b). Therefore, we speculate that the cat-
＋
echol and Cu2 interact in some way with the molar
spectrum (Figure 5). The result indicates that some of
the Cu2 ions are reduced into Cu＋. The peak around
＋
ratio of one to one since there are two pyrocatechols in
this one catechol compound. Fluorescence intensity in-
955.8 eV is obviously asymmetric, indicating that there
4
www.cjc.wiley-vch.de
© 2017 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2017, XX, 1—6

New Dopa-AIE Compound Used as Fluorescence Sensor Material
Figure 4 The fluorescence intensity of the compound in THF/water (6∶4 V/V) was changed by addition of CuCl2 solution. In the cu-
vette there are 2.5 mL of the catechol with the concentration at 0.5 mg/mL, and 5 μL of CuCl2 solution (20 mg/mL) were added succes-
sively to the cuvette. So, the molar ratio of pyrocatechol in the catechol to Cu2+ is 2∶1 after successive addition of CuCl2 solution 4.2
times. (A) The fluorescence intensity changes with the first 5 times addition of CuCl2; (B) The fluorescence intensity changes with the
following next 10 times addition of CuCl2; (C) The maximum value of the fluorescence intensity changes along with the concentration of
Cu2+. (D) The wavelength at the maximum value of the fluorescence intensity changes along with the addition times of copper.
as-synthesized compound, due to its special detection of
＋
Cu2 , we believe that the compound not only forms
complexes with the copper ion, more importantly, a
certain degree of redox reactions may also occur be-
tween copper and the catechol. Usually, redox reactions
occur depending on the potentials of the two matches.
Too much difference between them will lead to irre-
versible oxidation and/or reduction; while for too small
difference, there may not be a redox reaction. The cal-
culated HOMO-LUMO gap of the catechol is 0.139 eV.
＋
It might be due to the suitable change from Cu2 to
Cu＋ (＋0.159 eV) for the catechol to cause the fluores-
cence intensity change. And this redox process may be
occurring inside the complex without destroying the
catechol structure. Maybe this is the reason that we
Figure 5 The Cu 2p scan spectrum of the mixture of the cate-
chol and CuCl2. The powdered sample was prepared as follows:
The catechol was dissolved in THF, and an equal amount of
CuCl2 was added; subsequently, the solvent was evaporated after
cannot tell the structural difference of the catechol
with/without copper by 1H NMR and MS.
the mixture was stirred for 30 min.
are at least two different valences of copper ions in the
Conclusions
mixture. Thus, the peak at 933.8 eV could be attributed
to Cu＋ and the peak at 935.8 eV could be attributed to
In summary, a new kind of catechol, dopa-AIE
compound, has been synthesized and investigated. From
＋
Cu2 . Probably this change may have some relationship
the structural point of view, the as-synthesized com-
pound simultaneously has two functional group units,
AIE moiety as the core and dopa as the side group. Both
with the blue shift in Figure 4d. It is well known that
many compounds with catechol structures can form
complexes by complexation with metal ions. For the
Chin. J. Chem. 2017, XX, 1—6
© 2017 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
5

Liu, Cheng & Xu
FULL PAPER
[12] Barrett, D. G.; Fullenkamp, D. E.; Lihong, H.; Andersen, N. H.; Lee,
K. Y. C.; Messersmith, P. B. Adv. Funct. Mater. 2013, 23, 1111.
[13] Andersen, N. H.; Jaishankar, A.; Harrington, M. J.; Fullenkamp, D.
E.; DiMarco, G.; Lihong, H.; McKinley, G. H.; Messersmith, P. B.;
Lee, K. Y. C. J. Mater. Chem. B 2014, 2, 2467.
[14] Fullenkamp, D. E.; Barrett, D. G.; Miller, D. R.; Kurutz, J. W.; Mes-
sersmith, P. B. RSC Adv. 2014, 4, 25127.
[15] Lee, H.; Dellatore, S. M.; Miller, W. M.; Messersmith, P. B. Science
2007, 318, 426.
[16] Li, G.; Chen, L. C.; Chen, M. M.; Gao, B.; Xiong, X. L. Chem. J.
Chin. Univ. 2013, 34, 2493.
[17] Dwivedi, A. K.; Pandeeswar, M.; Govindaraju, T. ACS Appl. Mater.
Interfaces 2014, 6, 21369.
[18] Narayanan, K. B.; Park, H. H. Spectrochim. Acta, Part A 2014, 131,
132.
[19] Shi, B. F.; Zhang, L. L.; Lan, C. Q.; Zhao, J. J.; Su, Y. B.; Zhao, S. L.
Talanta 2015, 142, 131.
[20] Saragi, T. P. I.; Spehr, T.; Siebert, A.; Fuhrmann, L. T.; Salbeck, J.
Chem. Rev. 2007, 107, 1011.
[21] Grimsdale, A. C.; Chan, K. L.; Martin, R. E.; Jokisz, P. G.; Holmes,
A. B. Chem. Rev. 2009, 109, 897.
[22] Luo, J. D.; Xie, Z. L.; Lam, J. W. Y.; Cheng, L.; Tang, B. Z.; Chen,
H. Y.; Qiu, C. F.; Kwok, H. S.; Zhan, X. W.; Liu, Y. Q.; Zhu, D. B.
Chem. Commun. 2001, 174.
[23] Viguier, R. F. H.; Hulme, A. N. A. J. Am. Chem. Soc. 2006, 128,
11370.
[24] Georgopoulos, P. G.; Roy, A.; Yonone-Lioy, M. J.; Opiekun, R. E.;
Lioy, P. J. J. Toxicol. Environ. Health B 2001, 4, 341.
[25] Geng, J.; Li, M.; Wu, L.; Ren, J. S.; Qu, X. G. J. Med. Chem. 2012,
55, 9146.
[26] Barnham, K. J.; Masters, C. L.; Bush, A. I. Nat. Rev. Drug Discovery
2004, 3, 205.
of them can reflect their own characteristics inde-
pendently. That is, it not only has the similar character-
istics of AIE compounds, but also has similar adhesion
properties to dopa. Most importantly, the combination
of AIE core and dopa results in some new features for
the new catechol, showing the synergistic effect. The
new catechol has a unique fluorescence detection re-
sponse to Cu(II) in solution, and the response is quanti-
tative. The fluorescence intensity has the maximum
value when the molar ratio of the catechol to copper is
1∶1. Before and after this point, the fluorescence in-
tensity has a linear relationship with the copper ion
concentration. This result can help us design and fabri-
cate Cu(II) sensor, particularly for Cu(II) bio-sensor
because of the paramagnetism of Cu(II).
Acknowledgement
This study was partly supported by China Scholar-
ship Council. We also thank Prof. Mingmei Wu (Sun
Yat-sen University, China) for talking about XPS data,
and Phillip B. Messersmith (UC-Berkeley, US) for use-
ful discussion.
References
[1] Waite, J. H.; Tanzer, M. L. Science 1981, 212, 1038.
[2] Papov, V. V.; Diamond, T. V.; Biemann, K.; Waite, J. H. J. Biol.
Chem. 1995, 270, 20183.
[27] Viquier, R. F.; Hulme, A. N. J. Am. Chem. Soc. 2006, 128, 11370.
[28] Zhou, H.; Ye, Q.; Wu, X. Y.; Song, J.; Cho, C. M.; Zong, Y.; Tang, B.
Z.; Hor, T. S. A.; Yeow, E. K. L.; Xu, J. W. J. Mater. Chem. C 2015,
3, 11874.
[3] Waite, J. H.; Qin, X. X. Biochemistry 2001, 40, 2887.
[4] Lee, H.; Lee, B. P.; Messersmith, P. B. Nature 2007, 448, 338.
[5] Westwood, G.; Horton, T. N.; Wilker, J. J. Macromolecules 2007, 40,
3960.
[29] Zhang, S.; Yan, J. M.; Qin, A. J.; Sun, J. Z.; Tang, B. Z. Chinese
Chem. Lett. 2013, 24, 668.
[6] Wu, F. X.; Jun, L. L.; Messersmith, P. B. Biomacromolecules 2006,
7, 2443.
[30] Silvestri, M. A.; Naqarajan, M.; De Clercq, E.; Pannecouque, C.;
Cushman, M. J. Med. Chem. 2004, 47, 3149.
[7] Sileika, T. S.; Barrett, D. G.; Zhang, R.; Lau, K. H. A.; Messersmith,
P. B. Angew. Chem. 2013, 125, 10966.
[31] Banerjee, M.; Emond, S. J.; Lindeman, S. V.; Rathore, R. J. Org.
Chem. 2007, 72, 8054.
[8] Ham, H. O.; Park, S. H.; Kurutz, J. W.; Szleifer, I. G.; Messersmith,
P. B. J. Am. Chem. Soc. 2013, 135, 13015.
[32] Chi, Z. G.; Zhang, X. Q.; Xu, B. J.; Zhou, X.; Ma, C. P.; Zhang, Y.;
Liu, S. W.; Xu, J. R. Chem. Soc. Rev. 2012, 41, 3878.
[33] Zhang, G. F.; Chen, T.; Chen, Z. Q.; Aldred, M. P.; Meng, X. G.; Zhu,
M. Q. Chin. J. Chem. 2015, 33, 939.
[9] Black, K. C.; Sileika, T. S.; Yi, J.; Zhang, R.; Rivera, J. G.; Messer-
smith, P. B. Small 2014, 10, 169.
[10] Sedo, J.; Saiz-Poseu, J.; Busque, F.; Ruiz-Molina, D. Adv. Mater.
2013, 25, 65.
[34] Zhang, Y. H.; Kong, L. W.; Shi, J. B.; Tong, B.; Zhi, J. G.; Feng, X.;
Dong, Y. P. Chin. J. Chem. 2015, 33, 701.
[11] Faure, E.; Falentin-Daudre, C.; Jerome, C.; Lyskawa, J.; Fournier, D.;
Woisel, P.; Detrembleur, C. Prog. Polym. Sci. 2013, 38, 236.
(Lu, Y.)
6
www.cjc.wiley-vch.de
© 2017 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2017, XX, 1—6