Selective Chemosensor of Fe³⁺ Based on Fluorescence Quenching by 2,2′‐Bisbenzimidazole Derivative in Aqueous Media

Abstract

2,2'-Bisbenzimidazole derivative (L) was designed as a fluorescent chemosensor for Fe 3＋ . This structurally simple chemosensor displays significant fluorescence quenching with increasing concentrations of Fe 3＋ . L exhibited high selectivity and antidisturbance for Fe 3＋ among environmentally relevant metal ions in aqueous media. The method of Job's plot indicated the formation of 1∶2 complex between L and Fe 3＋ , and the possible binding mode of the system was also proposed. In addition, further study demonstrates the detection limit on fluorescence response of the sensor to Fe 3＋ is down to 10 −7 mol•L −1 range. The binding mode was investigated by fluorescence spectra, ESI-MS, IR data, 1 H NMR, 13 C NMR and crystal data.

5,5′,6,6′‐Tetranitro‐2,2′‐bibenzimidazole: A Thermally Stable and Insensitive Energetic Compound

“…[2][3][4] Nowadays, acommonly used methodf or the synthesis of BBI involves the reaction between oxalic acid and 1,2-diaminobenzene in ethylene glycol (autoclave, 180 8C) with phosphorous acid as acatalyst. [5] The BBI system is very stable owing to intermoleculara nd intramolecular hydrogen bonding. The broad delocalization of p electrons in the BBI system stabilizes it further.D uring thermal analysis ( DTA) in an open crucible, BBI does not decompose, but sublimes at about 400 8C.…”

Discriminating Chemosensor for Detection of Fe3+ in Aqueous Media by Fluorescence Quenching Methodology

“…[8][9][10] Amongst numerous methods used so far for the detection of a metal ion in aqueous solutions, fluorescent sensors with selective and sensitive characteristics are best candidates for onsite quantitative determination of metal ions from ordinary and pharmaceutical samples. [25][26][27][28][29][30] The hydrophobicity of such fluorescent chemosensors limits their direct use in detection of Fe 3+ from ordinary samples. 14,15 Iron can exist in oxidation states between −2 and +7, but the most common oxidation states of iron are ferrous (+2) and ferric (+3) states.…”

“…Although these techniques have its own advantages, these methods fail to produce quick response time, easy handling, high selectivity, sensitivity, low detection limit, and use of water as a major solvent in the analysis. The fluorescent‐based chemosensors are widely applied for detection of Fe 3+ in aqueous medium . The hydrophobicity of such fluorescent chemosensors limits their direct use in detection of Fe 3+ from ordinary samples.…”

Rutin-modified silver nanoparticles as a chromogenic probe for the selective detection of Fe3+in aqueous medium

“…Although the trivalent form of iron is particularly important for oxygen transport in blood and the mitochondrial respiratory chain, high levels of this cation are associated with important pathologies. 3,4 The detection of metal ions in aqueous solution is traditionally performed by methods including atomic absorption spectrometry, 5 electrochemical measurements, 6,7 and inductively coupled plasma techniques, 8 among others. However, these techniques have important drawbacks, notably the need for sophisticated instrumentation, in addition to being time-consuming and requiring laborious procedures.…”

“…2d), resulting in a nal single AgNPs population with average diameter of 14.7 nm AE 8.9 nm. Due to the strong alkaline medium, the main specie responsible for the behavior of NPs is likely to be Fe(OH) 3 . A schematic illustration of the mechanism involving aggregation of RU-AgNPs induced by the addition of Fe 3+ is presented in Fig.…”