Rapid and highly selective relay recognition of Cu(II) and sulfide ions by a simple benzimidazole-based fluorescent sensor in water

Phenazine containing indeno-furan based colorimetric and “on–off” fluorescent sensor for the detection of Cu 2+ and Pb 2+

“…S7(b)). This phenomenon is similar to the results of some recent reported studies [41], which indicates that the oxygen of carbonyl group coordinates with the Cu 2 þ ion. The possible binding mode of 1 was determined by 1 H NMR studies with Pb 2 þ as the paramagnetic nature of Cu 2 þ limits this application (Fig.…”

Design of a novel coumarin-based multifunctional fluorescent probe for Zn2+/Cu2+/S2− in aqueous solution

“…And, in short, firstly, the fluorescence of HL was quenched by Cu 2+ , and then Cu 2+ would be dragged out from the complex by S 2− which was known to react with Cu 2+ to make a very stable CuS (K sp = 6.3 × 10 −36 ), as a result, the quenched fluorescence recurred remarkably [50][51][52][53][54] (Scheme 3). It was further confirmed by the UV-vis spectra of reversible change [55][56][57]. Moreover, the selectivity of L-Cu for S 2 − was not affected by the presence of some other anions (Fig.…”

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

“…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.…”

“…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.…”