A novel turn off fluorescent sensor for Fe(III) and pH environment based on coumarin derivatives: the fluorescence characteristics and theoretical study

Synthesis and Application of Salicylhydrazone Probes with High Selectivity for Rapid Detection of Cu2

Using the aldehyde amine condensation procedure and the triphenylamine group as the skeleton structure, the new triphenylamine-aromatic aldehyde-succinylhydrazone probe molecule DHBYMH was created. A newly created acylhydrazone probe was structurally characterized by mass spectrometry (MS), NMR, and infrared spectroscopy (FTIR). Fluorescence and UV spectroscopy were used to examine DHBYMH's sensing capabilities for metal ions. Notably, DHBYMH achieved a detection limit of 1.62 × 10-7 M by demonstrating exceptional selectivity and sensitivity towards Cu2+ ions in an optimum sample solvent system (DMSO/H2O, (v/v = 7/3); pH = 7.0; cysteine (Cys) concentration: 1 × 10-4 M). NMR titration, high-resolution mass spectrometry analysis, and DFT computation were used to clarify the response mechanism. Ultimately, predicated on DHBYMH's reversible identification of Cu2+ ions in the presence of EDTA, a molecular logic gate was successfully designed.

Pyrene Substituted Phthalonitrile Derivative As a Fluorescent Sensor For Detection of Fe3+ Ions in Solutions

In this current study, the novel bis[4,5-(pyrene-2-yl)-3,6-(hexyloxy)] phthalonitrile (SPN) fluorophore has been successfully synthesized. Structural characterization of this novel compound was performed by different spectroscopic methods such as FT-IR, MALDI-TOF, ¹H-NMR, ¹³C-NMR and elemental analyses as well. In addition, the photophysical properties were determined using UV-vis absorption, steady-state fluorescence, time-resolved fluorescence spectroscopic methods and quantum chemical calculations. The metal sensing behavior of the SPN was determined in the presence of various metals (Li⁺, Na⁺, K⁺, Mg²⁺, Ca²⁺, Ba²⁺, Mn²⁺, Fe³⁺, Cr³⁺, Co²⁺, Ni²⁺, Ag⁺, Cd²⁺, Al³⁺, Hg⁺ and Zn²⁺) using fluorescence spectroscopy. The novel pyrene based phthalonitrile (SPN) showed high sensitivity and selectivity towards Fe³⁺ ion over other examined metal ions. In order to perform the determination of Fe³⁺ ion in environmental samples, experimental conditions such as selectivity, stability, precision, sensitivity, accuracy and recovery were optimized. Also, the complex stoichiometry of the novel pyrene based phthalonitrile (SPN) and Fe³⁺ ions was determined by a Job's plot. The compound was also studied via density functional theory calculations revealing the interaction mechanism of the molecule with Fe³⁺ ions.

Recent Advances in Organic Synthesis of 3-Amino- or 4-Aminocoumarins

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Coumarin is a privileged scaffold that contains the unique 2H-chromen-2-one motif, and its derivatives are widely distributed in nature, especially in plants. In recent years, due to their diverse pharmacological activities and remarkable photochemical properties, they have attracted significant attention from scientists, which has also prompted the research on the synthesis approaches and the availability of substrates for these compounds. This article is a brief description of the methods for the synthesis of various coumarin derivatives via two- or multi-component reactions involving 3-amino or 4-aminocoumarin reported during 2015-2021. This review may help expand the development of various analogues with coumarin as the basic unit.

Rational design and bioimaging application of water-soluble Fe3+ fluorescent probes

The carboxyl group improves the water-solubility of Fe³⁺ fluorescent probes, while resulting in different performances based on its position.

Coumarin-Based Small-Molecule Fluorescent Chemosensors

Coumarins are a very large family of compounds containing the unique 2H-chromen-2-one motif, as it is known according to IUPAC nomenclature. Coumarin derivatives are widely found in nature, especially in plants and are constituents of several essential oils. Up to now, thousands of coumarin derivatives have been isolated from nature or produced by chemists. More recently, the coumarin platform has been widely adopted in the design of small-molecule fluorescent chemosensors because of its excellent biocompatibility, strong and stable fluorescence emission, and good structural flexibility. This scaffold has found wide applications in the development of fluorescent chemosensors in the fields of molecular recognition, molecular imaging, bioorganic chemistry, analytical chemistry, materials chemistry, as well as in the biology and medical science communities. This review focuses on the important progress of coumarin-based small-molecule fluorescent chemosensors during the period of 2012-2018. This comprehensive and critical review may facilitate the development of more powerful fluorescent chemosensors for broad and exciting applications in the future.

Selective Sensing of Iron by Pyrrolo[2,3-c]Quinolines

This paper reports development of an iron sensor, 2-(3H-pyrrolo[2,3-c]quinolin-4-yl)aniline (APQ). The fluorophore facilitates micromolar detection of Fe³⁺/Fe²⁺ in the presence of various cations, including well-known interfering cations Co²⁺and Cu²⁺ by the process of fluorescence quenching. Graphical Abstract.

Selective and sensitive fluorescent and colorimetric chemosensor for detection of CO32- anions in aqueous solution and living cells

A new colorimetric and fluorescent chemosensor for visual determination of carbonate ions was developed by the microwave assisted solvent free synthesis of 7,8-dihydroxy-3-(4-methylphenyl) coumarin (DHMC). The structural characterization of DHMC was confirmed by microanalysis and spectroscopy methods (MALDI-TOF, FT-IR, ¹H NMR, ¹³C NMR, and 2D HETCOR). The binding behaviors of DHMC were investigated towards various anions by UV-vis and fluorescence spectroscopy. DHMC showed a selective and sensitive fluorometric and colorimetric responses towards carbonate ion over other anions. The detection limit of CO₃^2- was found to be 1.03 µM. Moreover, the fluorescence imaging in living cells suggests that DHMC has a great potential in the biological imaging application. It has been demonstrated that DHMC can be used as a rapid and reliable sensor for the determination of carbonate anion in a variety of practical applications.

A Selective Fluorescence Sensor for Fe (III) Based on Phenanthroimidazole Imine Compound

Experimental studies in the aqueous solution are crucial for the detection of metal cations in environmental and biological media. Polymer materials allow to work in aqueous media for fluorescent substances which are insoluble in water. Fluorescence sensor studies of the phenanthroimidazole imine compound (PI) synthesized previously by our group were performed in the polymer medium and the selective response to Fe (III) cation was obtained. The resulting sensor exhibited a selective fluorescence quenching effect to Fe (III). A logarithmic calibration graph was obtained in the range of 5.0 × 10^- 5 and 1.0 × 10^- 2 M. The interference effects of other ions besides Fe (III) have been examined and it has been observed that PI compound behaves selectively to Fe (III) ion in aqueous media. In addition, regeneration and reproducibility studies were carried out to determine the long-term usage of PI doped polymer film and reproducible results have been obtained for Fe (III) cation.

Sequential detection of Fe3+/2+ and pyrophosphate by a colorimetric chemosensor in a near-perfect aqueous solution

A colorimetric chemosensor was developed for Fe^3+/2+ and pyrophosphate with low detection limit and practical application for Fe³⁺ in water samples.