Sequential detection of Cu2+ and cysteine using an imidazole‐based chemosensor in aqueous solution. Issue 5 (15th November 2018)

• Record Type: Journal Article
• Authors: Saha, Baptu; Saha, Pinki; Mandal, Abhijit; Naskar, Jnan Prakash; Maiti, Debasish; Chowdhury, Shubhamoy
• Is Part Of: Journal of the Chinese Chemical Society. Volume 66:Issue 5(2019)
• Page Start: 506
• Page End: 514
• Publication Date: 2018-11-15
• Subjects: colorimetric -- copper -- cysteine -- fluorometric -- sequential detection; Chemistry -- Periodicals; Electronic journals; 540.5
• DOI: 10.1002/jccs.201800200
• Languages: English
• ISSNs: 0009-4536

Abstract

Abstract : A highly substituted imidazole‐based colorimetric and fluorogenic chemosensor, 2‐methoxy‐4‐(4, 5‐diphenyl‐1H‐imidazol‐2‐yl)phenol (L), for the detection of Cu 2+ ion and subsequent colorimetric detection of an amino acid, cysteine, was investigated. L exhibited a distinct color change from colorless to red in the presence of Cu 2+ in an aqueous medium. The L‐Cu 2+ complex can also be used to detect cysteine by the naked eye over a series of amino acids. The receptor L behaves as a highly selective colorimetric and fluorescent sensor for Cu 2+ ions at concentrations as low as 4.33 and 2.25 μM, respectively. These values are much less compared to the WHO recommended limit of 30 μM for Cu 2+ in drinking water. From Job's plot and the ESI‐MS spectrum, a 1:1 stoichiometric complex between L and Cu 2+ ions can readily be reckoned. This binding was also substantiated by the EPR spectrum and magnetic susceptibility measurements. Additionally, the binding of L with Cu 2+ ions was also manifested in the detection of B16F10 cells. This was substantiated through fluorescence microscopy. The spectrum of the L‐Cu 2+ entity was also attempted to reproduce theoretically. The probable structure of this was also propounded through Density Functional Theory. Abstract : 2‐methoxy‐4‐(4, 5‐diphenyl‐1H‐imidazol‐2‐yl)phenol was investigated as a sequential colorimetric sensor of Cu 2+, cysteine, and also to detect fluorometrically Cu 2+ in aqueous solution.