A new selective chromogenic and turn-on fluorogenic probe for copper(ii) in solution and vero cells: recognition of sulphide by [CuL]

Abstract

A new coumarin-appended thioimidazole-linked imine conjugate, viz. has been synthesized and characterized. has been found to recognize Cu(2+) selectively among a wide range of biologically relevant metal ions. The chemosensing behavior of has been demonstrated through fluorescence, absorption, visual fluorescence color changes, ESI-MS and (1)H NMR titrations. The chemosensor showed selectivity toward Cu(2+) by switch on fluorescence among the 18 metal ions studied with a detection limit of 1.53 μM. The complex formed between and Cu(2+) is found to be 1 : 1 on the basis of absorption and fluorescence titrations and was confirmed by ESI-MS. DFT and TDDFT calculations were performed in order to demonstrate the structure of and [CuL] and the electronic properties of chemosensor and its copper complex. This highly fluorescent [CuL] complex has been used to recognize sulphide selectively among the other allied anions. Microstructural features of and its Cu(2+) complex have been investigated by SEM imaging (scanning electron microscopy). The biological applications of were evaluated in Vero cells and it was found to exhibit low cytotoxicity and good membrane permeability for the detection of Cu(2+).

Cu2+ sensing via noncovalent complexes of fluorescent whitening agents and imidazole‐based polymeric dye transfer inhibitors

“…The performance of sensor A (FWA‐DTI complex) is comparable with other reported fluorescence‐based probes for Cu 2+ (Table ). Unlike many probes reported in the literature, the approach introduced herein produces 100% water‐soluble Cu 2+ sensors. The main advantage of the approach described in this work however, is its simplicity; it enables sensor assembly via single‐step mixing of inexpensive commercial materials, which circumvents the multistep synthesis and purification involved in the production of current Cu 2+ sensors.…”

Carbazole–azine based fluorescence ‘off–on’ sensor for selective detection of Cu2+ and its live cell imaging

“…The United States Environmental Protection Agency recommends an upper limit of 1.3 mg copper in humans . Because of the toxicity of copper ions and their role as a critical catalytic co‐factor in a variety of metallo enzymes, such as superoxide dismutase, cytochrome c oxidase and tyrosinasemore, researchers have explored efficient recognition probes for Cu 2+ . Although many analytical techniques have been developed, they are time consuming and expensive, and a simple, distinct reaction of toxic metal ions via colorimetric quantification is required.…”

Chemosensing Ensembles of 2-(2-Thiazolylazo)-p-cresol with Metal Ions in Colorimetric Detection of Anions

“…Metal ions take part in two distinct processes with two different roles, including (1) following the binding site-signaling subunit approach, in which the metal ion can act as binding site for the anion to form a strong coordinate bond; 6 and (2) following the displacement approach, in which the stability constant of a complex formed by metal-anion affinity is larger than that of the complex of a metal and its organic receptor. [9][10][11][12][13][14] Considering the above-mentioned information, we report herein the facile design of 2-(2-thiazolylazo)-p-cresol (TAC)-based metal complexes and the use of such ensembles for the selective and sensitive detection of anions. TAC was selected as the organic chromophore because it possesses multiple metal binding sites, such as nitrogen, sulfur, and oxygen atoms, which facilitate its binding with various metal ions.…”

“…Cu 2+ complexes have been widely developed as chemosensors for the detection of CN -and S 2-, and it operates through a displacement mechanism. [9][10][11][12][13][14]25 Sulfide is known to react with copper ions to make a stable CuS form with a low solubility product constant Ksp = 6.3 × 10 -36 of cyanide (3.2 × 10 -20 ). 26 However, designing a Cu 2+ complex-based chemosensor that can simultaneously detect and differentiate sulfide and CN -is highly challenging.…”

“…7,8 Recent studies have developed organic-metal ensemble-based chemosensors as an effective approach for anion recognition or sensing because of its operation simplicity, labor efficiency, quick response, high sensitivity, and good selectivity on a target anion. [9][10][11][12][13][14][15] This anion-recognizing ability can be tuned by varying the organic functionality 16 or the metal [17][18][19] of ensemble using a rational design. Rational designs of effective chemosensors are of paramount importance to achieve high affinity, selectivity, and sensitivity.…”