Selective Detection Of Fluoride Research Articles

Host-guest interactions of coumarin-based 1,2-pyrazole using analytical and computational methods: Paper strip-based detection, live cell imaging, logic gates and keypad lock applications

A novel Coumarin-based 1,2-pyrazole, HCPyTSC is synthesised and characterized. The chemosensor has been shown to have efficient colourimetric and fluorescence sensing capabilities for the quick and selective detection of fluoride and copper ions. At 376 and 430 nm, the HCPyTSC exhibits selective sensing for Cu2+ and F− ions. By examining the natural bond orbital (NBO) analysis and the potential energy curve (PES) of the ground state for the function of the C–H bond, it has been determined from the theoretical study at hand that the deprotonation was taken from the ‘CH’ proton of the pyrazole ring. For F− and Cu2+, the HCPyTSC detection limits were 4.62 nM and 15.36 nM, respectively. Similarly, the binding constants (Kb) for F− and Cu2+ ions in acetonitrile medium were found to be 2.06 × 105 M−1 and 1.88 × 105 M−1. Chemosensor HCPyTSC with and without F− and Cu2+ ions have an emission and absorption response that can imitate a variety of logic gates, including the AND, XOR, and OR gates. Additionally, a paper-based sensor strip with the HCPyTSC was created for use in practical, flexible F− sensing applications. The paper-based sensor was more effective in detecting F− than other anions. The effectiveness of HCPyTSC for the selective detection of F− in living cells as well as its cell permeability were examined using live-cell imaging in T24 cells.

Aggregation-Induced Emission, Mechanofluorochromism, and Selective Fluoride Detection by a Tripodal Salicylaldimine.

Fluoride ions are indispensable in biology and environmental science and hence the selective and sensitive detection of fluoride is important. This work reports the design and synthesis of a tripodal Schiff's base 1 through a simple condensation reaction between a commercially available aldehyde and an amine. Single crystal X-ray crystallography revealed that compound 1 is a planar entity with the three salicylidene derivatives on the three arms of the central phenyl moiety linked by imine groups. Compound 1 forms a molecular dimer that resembles a six-petal flower and is stabilized through multiple intermolecular interactions such as C-H.π and π.π interactions. Compound 1 exhibited moderately good emission in the solid state with aggregation induced emission and reversible mechanofluorochromic properties. Moreover, 1 was observed to selectively detect fluoride among various anions with a limit of detection of ∼9 ppm. Compound 1 was also capable of detecting fluoride under a variety of conditions such as in thin films and under cellular conditions.

Selective detection of fluoride and hydrogen sulfate anions by pyrimidine-based fluorescence chemosensor

The binding and sensing abilities of pyrimidine based fluorescence chemosensor L towards different anions such as F-, Cl-, Br-, I-, NO3-, ClO4-, H2PO4- and HSO4- have been examined by fluorescence spectroscopy in DMSO-H2O (7: 3, v/v). Upon successive addition of various anions to DMSO-H2O solutions of L; quenching in emission fluorescence is observed at 480 nm. Analysis of fluorescence emission changes suggested the formation of 1:1 complex of L with the anions. From the fluorescence binding constant data, it is found that L form strong complexes with F- and HSO4- ions through H-bonding interactions. The selective response of F- over other halides and HSO4- amongst other oxo-anions towards L may be explained on the basis of photo-induced electron transfer process.

Direct detection of fluoride ions in aquatic samples by surface-enhanced Raman scattering

Given the strong hydration propensity of fluoride ions, it is difficult to detect fluoride, especially inorganic fluoride, in aqueous samples. Resolving the issue of fluoride detection in aqueous samples is a scientific undertaking of great practical significance. Herein, we propose a new method for the sensitive and selective detection of fluoride in aqueous samples without the addition of organic solvents. The method involves surface-enhanced Raman spectroscopy using 1,4-diketo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DPP) compounds and Ag nanoparticles. The method is based on a diketopyrrolopyrrole compound linked to 1-butyl iodide (DPP1), which can sense fluoride sensitively and selectively. When DPP1 was combined with Ag NPs and reacted with tetrabutylammonium fluoride or inorganic fluoride in aqueous samples, an obvious Raman enhancement was obtained at the excitation wavelength of 633nm. This response arises because the introduction of fluoride anions into the system changes the molecular orientation of DPP1 on the Ag NP substrate from horizontal to vertical, inducing a signal enhancement in the Raman spectrum. This system can detect inorganic fluoride at concentrations as low as 1.0μmolL−1 (0.018ppm), which is far below the public health service recommended levels for drinking water (0.7–1.2ppm). Furthermore, using the proposed method, a linear response for fluoride in the concentration range of 1.0 × 10−3–1.0 × 10−6molL−1 was obtained, which makes fluoride detection possible in practical samples, such as fluoride-containing toothpaste.

Correction: Selective detection of fluoride using fused quinoline systems: effect of pyrrole

Correction for ‘Selective detection of fluoride using fused quinoline systems: effect of pyrrole’ by Mahesh Akula et al., RSC Adv., 2015, 5, 57231–57234.

Quantitative determination of fluoride in pure water using luminescent europium complexes.

Two luminescent probes [Eu.L¹⁻²]⁺ are reported for the rapid detection of fluoride in water. Probes [Eu.L¹⁻²]⁺ exhibit exceptional enhancements in Eu emission in the presence of fluoride, permitting its selective determination within the environmentally relevant concentration range (20-210 μM).

Design and synthesis of ultrasensitive off-on fluoride detecting fluorescence probe via autoinductive signal amplification.

We prepared an off-on fluorometric probe, DPF1, by incorporating the concept of autoinductive signal amplification into its molecular design. In the presence of fluoride, DPF1 undergoes a cascade of self-immolative reactions concomitant with unmasking fluorogenic coumarin, which results in the ejection of two fluoride ions. These fluoride ions are continuously activating the cascade reaction and accumulating coumarins, which leads to exponentially amplifying the signal with high sensitivity. The fluorescence signal generated by this cascade reaction is rapid, specific and insensitive to other anions. Its limit of detection was 0.5 pM, considerably lower than other current methods of fluoride detection. In addition, DCC, a long wavelength fluorometric probe, was prepared. Interestingly, an assay platform coupling DPF1 and DCC showed an outstanding sensing ability at higher wavelengths, suggesting that this can be a promising method for the sensitive and selective detection of fluoride in biological samples. The practical applicability of the proposed approach has been demonstrated in urine and water samples.

Selective detection of fluoride using fused quinoline systems: effect of pyrrole

A hybrid pyrrole-quinoline system has been used for selective sensing of fluoride anion; presence of pyrrole ring is essential for detection.

Highly sensitive and selective fluoride detection in water through fluorophore release from a metal-organic framework

The detection, differentiation and visualization of compounds such as gases, liquids or ions are key challenges for the design of selective optical chemosensors. Optical chemical sensors employ a transduction mechanism that converts a specific analyte recognition event into an optical signal. Here we report a novel concept for fluoride ion sensing where a porous crystalline framework serves as a host for a fluorescent reporter molecule. The detection is based on the decomposition of the host scaffold which induces the release of the fluorescent dye molecule. Specifically, the hybrid composite of the metal-organic framework NH2-MIL-101(Al) and fluorescein acting as reporter shows an exceptional turn-on fluorescence in aqueous fluoride-containing solutions. Using this novel strategy, the optical detection of fluoride is extremely sensitive and highly selective in the presence of many other anions.

Rapid and selective detection of fluoride in aqueous solution by a new hemicyanine-based colorimetric and fluorescent chemodosimeter

A novel merocyanine-based chemodosimeter was developed to detect fluoride ions in aqueous solution. This chemodosimeter was found to be a highly selective and sensitive colorimetric and fluorescent sensor for fluoride, and moreover, it shows a fast response within a few minutes to fluoride, thus providing a new and very promising sensor for rapid detection of fluoride in aqueous solution.