J Fluoresc
DOI 10.1007/s10895-014-1404-1
SHORT COMMUNICATION
A Quinoline Derivative as an Efficient Sensor to Detect
Selectively Al3+ ion
Cheng-Yin Huang & Yi Jhong & Jiun-Ly Chir & An-Tai Wu
Received: 20 December 2013 /Accepted: 19 May 2014
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Springer Science+Business Media New York 2014
Abstract A quinoline-based Schiff base 1 has been utilized
as a fluorescence chemosensor for the selective detection of
Al3+. The receptor 1 exhibited a high association constant
(3.67×105 M−1) with submicromolar detection limit
(0.18 ppm) towards Al3+ in CH3CN solution.
practical applications, it is necessary to develop Al3+ sensors
that are easily prepared, and possess selective and sensitive
signaling mechanisms.
Most of the fluorescent sensors structures for Al3+ contain
nitrogen–oxygen-rich coordination environments which
could provide a hard-base environment for the hard-acid
Al3+. Recently, 8-hydroxyquinoline and its derivatives are
efficient candidates for many metal ions recognition and are
widely used by many researchers for the synthesis of sensors
for selective detection many metal ions [27–30]. The well-
known 8-hydroxyquinoline derivative 1 (receptor 1) has been
synthesized by previous reports [31, 32]; however, its
chemosening behavior towards metal ions has not been inves-
tigated yet. Here, we reported receptor 1 exhibited a highly
selective detection towards Al3+ among a series of metal ions.
In addition, the receptor 1 exhibited a high association con-
stant with submicromolar detection limit towards Al3+ in
CH3CN solution (Scheme 1).
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Keywords Chemosensor Fluorescence Turn-On
Quinoline
In recent years, fluorescent chemosensors have attracted sig-
nificant interest because of their potential application in me-
dicinal and environmental research. Thus, many fluorescent
chemosensors specific for Hg2+, Cu2+, Zn2+ or other transition
metals have been developed. Compared to these transition
metal ions, only a few fluorescent chemosensors have been
reported for detection of Al3+ [1–21]. Al3+ most widely exists
in the environment due to acidic rain and human activities. Its
toxicity not only hampers plant growth but also damages the
human nervous system to induce Alzheimer’s disease,
Parkinson’s disease, amyotrophic lateral sclerosis, etc. [1, 4,
22–25]. Therefore, detection of Al3+ is crucial in controlling
its concentration levels in the biosphere and its direct impact
on human health. The detection of Al3+ has always been
problematic due to the lack of spectroscopic characteristics
and poor coordination ability [26]. In addition, the majorities
of the reported Al3+ has limitations such as requiring compli-
cated synthesis and are insoluble in polar solutions. For
The chemosensor behavior of receptor 1 with the following
15 metal ions (as perchlorate salts): Li+, Na+, K+, Ca2+, Mn2+,
Hg2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Pb2+, Cd2+, Zn2+ and Al3+
in CH3CN, was investigated by UV–vis and fluorescence
measurements. Receptor 1 shows significant variations of
the absorption spectrum in the 300–470 nm range (Fig. S2)
for all the added metal ions. However, from the fluorescence
spectra of receptor 1 (Fig. 1), receptor 1 alone and other
cations all displayed very weak single fluorescence emission
band at 480 nm when it was excited at 346 nm except for Al3+.
Upon addition of Al3+, receptor 1 exhibited a prominent
fluorescence enhancement with the quantum yield of 0.024
and accompanied a red shift of 27 nm from 450 to 477 nm.
Based on the use of a UV lamp, in the presence of Al3+, the
solution of receptor 1 showed a dramatic color change from
dark blue to light blue which could easily be detected by the
naked-eye. (Fig. 2). In addition, the fluorescent enhancement
efficiency observed at 477 nm was 570-fold greater than the
Electronic supplementary material The online version of this article
which is available to authorized users.
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C.<Y. Huang Y. Jhong J.<L. Chir A.<T. Wu (*)
Department of Chemistry, National Changhua University of
Education, Changhua 50058, Taiwan
e-mail: antai@cc.ncue.edu.tw
Huang, Cheng-Yin
