Smartphone‐Assisted Quinoline‐Based Chromogenic Probe for the Selective Detection of Hg2+ in Protic Media. Issue 2 (12th January 2022)

• Record Type: Journal Article
• Authors: Kumar, Saravana S.; Kumar, Selva R.; Vetriarasu, V.; Bhaskar, R.; Somkuwar, Pranati; Joseph, Suman; Mohurle, Shital; Ashok Kumar, S. K.
• Is Part Of: ChemistrySelect. Volume 7:Issue 2(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-12
• Subjects: Colorimetric sensor -- Quinoline -- Mercury -- RGB -- DFT; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.202103422
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: High selectivity and sensitivity detection of Hg 2+ in aqueous environment by the naked‐eye has always been a challenge. In this paper, a simple ligand based on 2‐(hydroxymethyl)quinolin‐8‐ol (L ) was synthesized and its structure was confirmed by NMR, IR and mass analysis. The probe L showed distinct colorimetric upon interaction with Hg 2+ in CH3 OH‐H2 O (8 : 2, v/v) media. The ligand L exhibit unique absorbance band at 243 nm due to ligand‐to‐ligand charge transfer (LLCT). Upon interaction with Hg 2+, the L formed new UV‐Vis bands at 269 and 316 nm due to ligand‐to‐metal charge transitions (LMCT). The UV‐Vis spectral studies indicate the formation of a 1 : 1 host‐guest complex between the L and Hg 2+ with an association constant of 8.6×10 4 M −1 . The ligand L can work in the pH range of 3–8 without interfering with other competing ions. The detection limit of Hg 2+ can reach a concentration of as low as 0.13 μM (2.6 ppb) with high selectivity, even in a solution containing diverse metal ions. Besides, the selective colour change of L with Hg 2+ was integrated with smartphone to monitor the change in RGB tool and test paper kit. The binding mechanism of L with Hg 2+ was studied by using 1 H NMR, SEM and TDDFT analysis. Overall, ligand L demonstrates a promising and potential for the detection of toxic contaminate in aqueous environment. Abstract : A new 8‐hydroxy 2‐hydroxymethyl quinoline based ligand L exhibits colorimetric and chromogenic responses with Hg 2+ ions. It can detect Hg 2+ as low as 2.6 ppb level. The selective color change of L with Hg 2+ was integrated with smartphone based RGB detection method detect Hg 2+ down to 30ppb. The binding mechanism of L‐Hg 2+ formation was studied by 1 H NMR, mass and DFT.