Article
DOI: 10.1002/bkcs.10551
BULLETIN OF THE
F. Ge et al.
KOREAN CHEMICAL SOCIETY
Fluorescence Sensor Performance of a New Fluorescein Derivate:
[
2-Morpholine-4-(6-chlorine-1,3,5-s-triazine)-amino]fluorescein
Fengyan Ge, Chun Yang, and Zaisheng Cai†
†,*
‡
†College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620,
China. *E-mail: fyge@dhu.edu.cn
‡
Wuhan Product Quality Supervision & Testing Institute, Wuhan 430043, China
Received April 14, 2015, Accepted July 27, 2015, Published online October 4, 2015
A novel reactive fluorescent dye [2-morpholine-4-(6-chlorine-1,3,5-s-triazine)-amino]fluorescein based on
5
-aminofluoresceinwas synthesized by electrophilic substitution. Thephotophysical properties, solvent effect,
pH value sensitivity, and metal ions responsibility of this new fluorophore were investigated. Compared with
-aminofluorescein, the novel fluorophore exhibited stronger fluorescence and longer lifetime. The fluores-
5
cence property of the new dye was obviously affected by different solvents and pH values, and it showed
stronger fluorescence in the protic solvents or an alkaline environment. Moreover, the fluorescent intensity
2+
could be enhanced by the formation of complex with metal ions especially with Mg . The results show that
the fluorescent dye is a promising efficient sensor for solvents, protons, and metal ions.
Keywords: [2-Morpholine-4-(6-chlorine-1,3,5-s-triazine)-amino]fluorescein, Solvent, pH, Metal ion,
Fluorescence sensor
Introduction
In this paper, the structure of this novel fluorescein deriva-
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tive DTAF-MOR was confirmed by H and C NMR spectra,
MS (ESI) spectra, and FT-IR spectra. And the photophysical
properties, solvent effect, pH value sensitivity, and metal ions
responsibility were also investigated.
During thepast years, fluoresceinand its derivatives havebeen
1
–8
widely employed as molecular probes in chemical biology.
More attention has been paid to aminofluorescein
AF) because it could specifically combine with the biomole-
(
cules at the site of –OH, –SH, and –COOH, which makes it a
potential fluorescent probe. However, AF has a low quantum
yield of 0.015 and exhibits none of fluorescein’s indicator
properties which restrict its application. Munkholm reported
that AF can recover the fluorescence till the electron lone pair
of the amine is unavailable for electron transfer through cova-
Experimental
Materials. All solvents were purchased from Sinopharm
Chem (Shanghai, China) and used without further purifica-
tion. To adjust the pH value, very small volumes of hydrochlo-
ric acid and sodium hydroxide were used. NiSO ꢀ6H O,
4
2
9
lent or electrostatic binding process. According to the work of
MnSO ꢀH O, CoSO ꢀ7H O, MgSO ꢀ7H O, ZnSO ꢀ7H O,
4
2
4
2
4
2
4
2
Munkholm, the reaction between AF and less electrophilic
species (for example, triazine chloride or sulfonyl chloride)
could recover the fluorescence. As an important bridge mole-
cule and a synthetic intermediate, the triazine chloride has
been widely used in the preparation of dyes and fluorescein
brightening agents due to the fact that the three chlorine atoms
on the triazine ring can be substituted subsequently.
Following the principle mentioned above, we fabricated
and synthesized a novel reactive fluorescein derivative [2-
morpholine-4-(6-chlorine-1,3,5-s-triazine)-amino]fluores-
cein, namely DTAF-MOR, by combining 5-AF and morpho-
line with triazine chloride which is a typical electrophilic
species for the fluorescence recovery. Meanwhile, the intro-
duction of triazine chloride brings more reactive sites for com-
bining with biomolecules and textiles, which in turn reinforce
the bonding fastness. In addition, an environmental responsi-
ble ability was obtained because the morpholine molecule can
form complex with metal ions and improve the sensitivity to
solvents and pH values.
FeSO ꢀ7H O, CuSO ꢀ5H O, Cd(NO ) ꢀ4H O, BaCl ,
4
2
4
2
3 2
2
2
AgNO , K SO , Na SO , Pd(NO ) , and CaCl salts were
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2
4
2
4
3 2
2
the sources for metal ions. The effect of metal ions on the fluo-
rescent intensity was examined by continually adding 12 μL
−5
metal ions solution (5.0 × 10 mol/L) to 3 mL dye solution
−
6
(5.0 × 10 mol/L). To avoid the influence of the dilution,
the addition was limited to 96 μL.
Methods. H and C spectra were recorded on Bruker AM
300 and Bruker AV-400 spectrometer (Billerica, MA,
USA), respectively. The measurements were carried out in
DMSO-d or CDCl solution using tetramethylsilane (TMS)
as an internal standard. Fourier transform infrared spectros-
copy (FT-IR) spectra were recorded on a Perkin-Elmer
2000 spectrometer (Waltham, MA, USA) using KBr disks.
MS was taken on a Varian 310-MS (Palo Alto, CA, USA).
UV–Vis spectra were recorded on a HITACHI U-3310 spec-
trophotometer (Tokyo, Japan) at the room temperature. The
fluorescence spectra were examined on a HITACHI F-7000
fluorescence spectrophotometer and fluorescence lifetime
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Bull. Korean Chem. Soc. 2015, Vol. 36, 2703–2709
© 2015 Korean Chemical Society, Seoul & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Wiley Online Library
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