title: A new visible-light-excitable ICT-CHEF-mediated fluorescence 'turn-on' probe for the selective detection of Cd(2+) in a mixed aqueous system with live-cell imaging.
abstract: A new quinoline based sensor was developed and applied for the selective detection of Cd(2+) both in vitro and in vivo. The designed probe displays a straightforward approach for the selective detection of Cd(2+) with a prominent fluorescence enhancement along with a large red shift (∼38 nm), which may be because of the CHEF (chelation-enhanced fluorescence) and ICT (internal charge transfer) processes after interaction with Cd(2+). The interference from other biologically important competing metal ions, particularly Zn(2+), has not been observed. The visible-light excitability of the probe merits in the viewpoint of its biological application. The probe enables the detection of intracellular Cd(2+) with non-cytotoxic effects, which was demonstrated with the live RAW cells. The experimentally observed change in the structure and electronic properties of the sensor after the addition of Cd(2+) were modelled by the density functional theory (DFT) and time-dependent density functional theory (TDDFT) computational calculations, respectively. Moreover, the test strip experiment with this sensor exhibits both absorption and fluorescence color changes when exposed to Cd(2+) in a mixed aqueous solution, which also makes the probe more useful. The minimum limit of detection of Cd(2+) by the probe was in the range of 9.9 × 10(-8) M level.
authors.affiliation: Department of Chemistry, Indian Institute of Engineering Science and Technology, Shibpur, Howrah-711 103, India. spgoswamical@yahoo.com.
authors.forename: Shyamaprosad
authors.initials: S
authors.lastname: Goswami
authors.forename: Krishnendu
authors.initials: K
authors.lastname: Aich
authors.forename: Sangita
authors.initials: S
authors.lastname: Das
authors.forename: Chitrangada
authors.initials: C
authors.lastname: Das Mukhopadhyay
authors.forename: Deblina
authors.initials: D
authors.lastname: Sarkar
authors.forename: Tapan Kumar
authors.initials: TK
authors.lastname: Mondal
mesh_terms: D002104:Cadmium / Q000032:analysis*; D002413:Cations, Divalent / Q000032:analysis; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D045325:HCT116 Cells; D006801:Humans; D008027:Light; D061848:Optical Imaging; D011804:Quinolines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014867:Water / Q000032:analysis
chemical_list: D002413:Cations, Divalent; D005456:Fluorescent Dyes; D011804:Quinolines; D002104:Cadmium; D014867:Water; C037219:quinoline