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Chemistry Education 2018
Journal of Organic & Inorganic Chemistry
ISSN: 2472-1123
Page 46
August 27-28, 2018
Zurich, Switzerland
8
th
Edition of International Conference on
Chemistry Education
and Research
T
here is a huge scope for the exploration of the role of zinc in
biological systems. Therefore, it is highly desired to develop
a sensitive method for its detection. Unlike other metal ions such
as Mn
2+
, Fe
2+
, or Cu
2+
, the Zn
2+
in biological systems cannot be
detected by spectroscopic methods, thus the fluorescence stands
out as a method of choice. The Hqpzc, N-(quinoline-8-yl)pyrazine-
2-carboxamide, as a small fluorogenic molecule with a selective
''Off-On'' switching behavior for detection of Zn
2+
and a colorimetric
sensor for Cu
2+
, comprises of quinoline as the fluorophore and
pyrazine-2-carboxamide as the chelating group. This chemosensor
exhibits a remarkable fluorescence response with a detection
limite of 1.11 × 10
−6
M when investigated in acetonitrile and the
fluorescence intensity enhances significantly upon addition of
one equivalent of Zn
2+
. The selectivity of Hqpzc for Zn
2+
is based
on the chelation-enhanced fluorescence (CHEF) mechanism. The
binding mode of the Hqpzc with Zn
2+
was investigated through
Job's plot experiment, the fluorescence and UV–vis titration, ESI-
MS, and density functional theory calculations. These results
revealed that the binding stoichiometric ratio between Hqpzc and
Zn
2+
in acetonitrile is 1:1. The limit of detection (LOD) for Cu
2+
is
1.48 × 10
−5
M in acetonitrile solvent and the association constant
(K
a
) for Hqpzc-Zn
2+
and Hqpzc-Cu
2+
complexes are 3.837 × 10
4
and
7.352 × 10
7
M
-1
, respectively. Other interfering ions such as Na
+
, K
+
,
Ca
2+
, Mg
2+
, Fe
2+
, Co
2+
, Ni
2+
, Cu
2+
, Cd
2+
, Hg
2+
, Mn
2+
, Cr
3+
and Al
3+
, show
either no or slight change in the fluorescence intensity of Hqpzc in
the presence of Zn
2+
. Notably, in the presence of Zn
2+
, the Hqpzc
fluorescence exhibits reversibility with SCN
–
, and the fluorescent
signals of Hqpzc are utilized to construct an INHIBIT type logic gate
at themolecular level. Theoretical calculations, carried out withTD-
DFTmethod, support the experimental observations.
Biography
Marzieh Sohrabi is a PhD student in Inorganic Chemistry, Isfahan University
of Technology, Isfahan, Iran. Bsc. Azad University of Shahr-e-Rey, Tehran, Iran,
2003; MSc. Azad University of Shahr-e-Rey, Tehran, Iran, 2008. Research inter-
est: Synthesis and characterization of emissive ligands and their metal com-
plexes with their application as sensors for detection of biologically important
ions such as Co
2+
, Cu
2+
, Zn
2+
. Construction of molecular probes for application
in live cell imaging. Construction of molecular logic gates from chemical light
switches based on emission properties of small molecules. Synthesis and
characterization of emissive organometallic complexes and their application
in biology as anticancer drugs, and computational chemistry.
msohrabi83@yahoo.comA novel chemosensor acting as a fluorescent "Off-On"
Zn
2+
sensor: Experimental, logic gate behavior and TD-DFT
calculations
Marzieh Sohrabi
1,2
, Mehdi Amirnasr
1
, Hossein Farrokhpour
1
and
Soraia Meghdadi
1
1,2
Isfahan University of Technology, Iran
1
Islamic Azad University, Iran
Marzieh Sohrabi et al., J Org Inorg Chem 2018, Volume 4
DOI: 10.21767/2472-1123-C5-015