ABSTRACT
The excited state intra molecular charge transfer (ICT) property of fluorophores has been extensively used for the design of fluorescent chemosensors. Herein, we report the synthesis and properties of three donorπ-acceptorπ-donor (Dπ-Aπ-D) based molecular probes BP, BT and BA. Two heteroaromatic rings, pyrrole (BP), and thiophene (BT) and a non-heteroaromatic ring N-alkoxy aniline (BA) were selected as donor moieties which were linked to a bipyridine binding site through a vinylic linkage. The heteroaromatic systems BP and BT perform selective and ratiometric emission signalling for zinc ions whereas the non-heteroaromatic probe BA does not. The advantages of the Dπ-Aπ-D design strategy in the design of ICT based probes for the selective fluorescent ratiometric signalling of zinc ions in biological media is discussed. Further, the use of BP, BT and BA for imaging Zn(2+) ions from MCF-7 cell lines is demonstrated.
Subject(s)
Fluorescent Dyes/chemistry , Microscopy, Fluorescence , Zinc/analysis , Amines/chemistry , Humans , Hydrogen-Ion Concentration , Ions/chemistry , MCF-7 Cells , Pyrroles/chemistry , Quantum Theory , Spectrometry, Fluorescence , Thiophenes/chemistryABSTRACT
The tunable excited-state properties of a new donor-π-acceptor-π-donor-type fluorophore 1 with a bipyridyl moiety and its ability to respond to different analytes in solution and on paper microchannels are described. Furthermore, the multiple analyte response of fluorophore 1 has been exploited to perform multiple logic operations. Molecule 1, by virtue of its excited-state charge transfer, exhibits solvatochromism and reversible modulation of its emission in response to multiple chemical inputs, thus resulting in different fluorescent signals. The intraligand charge-transfer (ILCT) emission of 1 at 574 nm has been modulated to three emission outputs by using different chemical inputs, such as Zn(2+), H(+), and ethylenediaminetetraacetic acid (EDTA). Thus, different logic operations such as AND, 2-input-INH, 3-input-INH, IMP, and a combination of these logic operations could be achieved.
ABSTRACT
A chiral π-conjugated oligomer having alternate bipyridine and carbazole moieties connected through acetylinic bonds undergoes helical folding in chloroform-acetonitrile (40/60, v/v) as evident by fluorescence and circular dichroism changes. In the presence of transition metal cations such as Zn(2+) defolding of the helical conformation occurs. Upon decomplexation of the cation with EDTA, the helical conformation is regained.
Subject(s)
Cations/chemistry , Pyridines/chemistry , Carbazoles/chemistry , Circular Dichroism , Edetic Acid/chemistry , Zinc/chemistryABSTRACT
A Zn(2+)-specific molecular probe 3 was developed for the selective detection of CN(-) under aqueous conditions. The fluorescent Zn(2+) complex of 3 upon CN(-) addition generates a bright blue fluorescence that allows the detection of the latter and is useful for the screening of natural products with and without endogenous cyanide content.
Subject(s)
Chlorides/chemistry , Cyanides/analysis , Fluorescent Dyes/chemistry , Organometallic Compounds/chemistry , Zinc Compounds/chemistry , Carica/chemistry , Colorimetry/methods , Latex/chemistry , Mangifera/chemistry , Manihot/chemistry , Molecular Structure , Spectrometry, Mass, Electrospray Ionization/methodsABSTRACT
A pyrrole end-capped bipyridyl ligand incorporating a chiral handle exhibited high solid-state emission when compared to the achiral analogue 1b and to the racemic molecule 1c which allowed the design of a reusable fluorescent probe for the selective detection of Zn2+ under aqueous conditions.
Subject(s)
2,2'-Dipyridyl/chemistry , Fluorescent Dyes/chemistry , Zinc/chemistry , Cations/chemistry , Circular Dichroism , Molecular Structure , Photochemistry , StereoisomerismABSTRACT
A tailor made squaraine dye upon binding with Ca2+ self-assembles to form a spherical micellar assembly that reorganises to thermodynamically stable 1D cylindrical rods with high molar absorptivity.
