Highly selective colorimetric and fluorometric chemosensor for cyanide on silica gel and DMSO/H2O (7:3 v/v) mixed solvent and its imaging in living cells

Bisphenol-based cyanide sensing: Selectivity, reversibility, facile synthesis, bilateral "OFF-ON" fluorescence, C2ν structural and conformational analysis

A structurally characterized novel dual-pocketed tetra-conjugated bisphenol-based chromophore (fluorescence = 652 nm) was synthesized in gram scale in ~90% yield from its tetraaldehyde. Highly selective, naked-eye detection of CN^- (DMSO/H₂O) was confirmed by interferent testing. A detection limit of 0.38 µM, within the permissible limit of CN^- concentration in drinking water was achieved as mandated by WHO. The "reversibility" study shows potential applicability and reusability of Sen. Moreover, cost-effective and on-site interfaces, application tools such as fabricated cotton swabs, plastic Petri dishes, and filter papers further demonstrated the specific selectivity of Sen for the toxic CN^-. In addition, an easily available and handy smartphone-assisted "Color Picker" app was utilized to help estimate the concentration of CN^- ion present. A dual phenol deprotonation mechanism is active and supported by ¹H NMR spectroscopic data and DFT calculation results.

Two novel tetraphenylethylene-skeleton salamo-type fluorescent probes: specific recognition of cyanide through different response patterns

The possible sensing mechanism of probes TPES1 and TPES2 towards CN− ions.

Dimethyl sulfoxide as a strongly coordinating solvent: 3′,4′-dihydroxyflavone-Cu(II)-DMSO system case study

Dimethyl sulfoxide (DMSO) is an aprotic organic solvent widely used in laboratory practice due to its ability to dissolve both polar and nonpolar compounds. However, DMSO is also commonly known as a strongly coordinating solvent, especially towards transition metal containing complexes. In this study, estimation of the coordination ability of DMSO towards the Cu(II) ion was attempted, employing a model system composed of 3′,4′-dihydroxyflavone-Cu(II) complex in the presence of explicit DMSO molecules, using the density functional theory (DFT). Nature of the Cu-DMSO chemical interaction (i.e. Cu-O bonding) was studied within the framework of quantum theory of atoms in molecules (QTAIM). Impact of DMSO coordination on the charge and spin distribution at Cu(II) ion was inspected using Mulliken population and QTAIM analysis.

Naphthalimide based smart sensor for CN−/Fe3+ and H2S. Synthesis and application in RAW264.7 cells and zebrafish imaging

Probe R designed as tailor-fit triple action smart chemosensor for the sequential detection of CN⁻ and Fe³⁺via colorimetric and fluorometric ‘on–off’ method and H₂S through colorimetric method in semi-aqueous conditions.

Visual detection of cyanide ion in aqueous medium by a new chromogenic azo-azomethine chemosensor

A simple and new chromogenic azo-azomethine chemosensor N'-(5-((2,4-dichloro- phenyl) diazenyl)-2-hydroxylbenzylidene) picolinohydrazide (L) has been synthesized as an effective colorimetric sensor for cyanide ion. The sensing behavior of the probe L towards CN^- over other anions was examined by naked-eye, UV-vis spectroscopy and NMR studies. L exhibited a selective sensing ability to CN^- in DMSO/H₂O(6:4, v:v) binary solution and DMSO/Tris(10 mM, pH = 7.1, 6:4, v:v) buffer solution by changing color from colorless to yellow. The detection limit was calculated to be 6.4 μM. The recognition mechanism was attributed to deprotonation process according to ¹H NMR titration method. Moreover, test strips coated with L were easily fabricated with low cost and could be used to detect CN^- in aqueous solution conveniently.

A new ratiometric, colorimetric and ‘‘turn-on’’ fluorescent chemosensor for the detection of cyanide ions based on a phenol–bisthiazolopyridine hybrid

This optical probe recognizes CN⁻ over various anions and cations via the deprotonation mechanism as evidenced by ¹H NMR titration.

A simple azoquinoline based highly selective colorimetric sensor for CN− anion in aqueous media

Azoquinoline based sensor AZQ was designed and synthesized as a new molecular ion sensor containing an azo group in its structure. The structural characterization of AZQ was carried out using FTIR, NMR, mass, and elemental analysis. Then, the interaction of AZQ with anions was observed visually and UV–vis measurements were made in EtOH/H2O (1:1, v/v) solvent mixture. As a result of this investigation, it was determined that AZQ is a fast and highly selective sensor for CN− ions. The solution colour of AZQ changed from light yellow to orange only in the presence of CN− ions. The limit of detection of AZQ was calculated as 2.6 μmol/L from anion titration experiments. Also, to identify the interaction mechanism of AZQ with CN− ions, 1H NMR spectra of AZQ in the presence of CN− anions were recorded and the structure was proposed for AZQ-CN− host–guest complex.

A highly selective colorimetric chemosensor for cyanide and sulfide in aqueous solution: experimental and theoretical studies

A selective chemosensor was developed for the colorimetric detection of CN⁻ and S²⁻ in aqueous solution.

Triphenylamine based lab-on-a-molecule for the highly selective and sensitive detection of Zn2+ and CN− in aqueous solution

A triphenylamine based lab-on-a-molecule TATP was designed and synthesized as a bifunctional sensor for the detection of Zn²⁺ and CN⁻ through fluorescence and UV-Vis absorption channels, with detection limits of 14 nM and 0.37 μM, respectively.