title: CHEF induced highly selective and sensitive turn-on fluorogenic and colorimetric sensor for Fe3+.
abstract: A new fluorescent probe was synthesized from rhodamine-6G and 6-(hydroxymethyl) picolinohydrazide for the sensing of Fe(3+) in an aqueous environment. The structure of the sensor was confirmed through its single crystal X-ray study. It exhibits a high specificity and sensitivity towards Fe(3+) over other interfering heavy and transition metal ions (HTM). The turn-on greenish-yellow fluorescence and a colorimetric change from colourless to pink were observed upon addition of Fe(3+) which evokes almost 116- and 23-fold enhancement in absorbance and emission intensity respectively in an acetonitrile-water (1:1, v/v, 25 °C) solution at a neutral pH (pH = 7.2). The Fe(3+) promoted ring opening of the spirolactam framework to the open chain amide platform of the sensor is responsible for its visible colour change and turn-on fluorescence activity. It also exhibits an excellent performance in the "dip stick" method. Moreover the limit of detection of the probe is in the 10(-8) M range.
authors.affiliation: Department of Chemistry, Bengal Engg. and Science University, Shibpur, Howrah-711 103, India. spgoswamical@yahoo.com.
authors.forename: Shyamaprosad
authors.initials: S
authors.lastname: Goswami
authors.forename: Sangita
authors.initials: S
authors.lastname: Das
authors.forename: Krishnendu
authors.initials: K
authors.lastname: Aich
authors.forename: Deblina
authors.initials: D
authors.lastname: Sarkar
authors.forename: Tapan Kumar
authors.initials: TK
authors.lastname: Mondal
authors.forename: Ching Kheng
authors.initials: CK
authors.lastname: Quah
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D003124:Colorimetry; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D007501:Iron / Q000032:analysis* / Q000737:chemistry; D057230:Limit of Detection; D008958:Models, Molecular; D015394:Molecular Structure; D011789:Quantum Theory; D012235:Rhodamines / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D002614:Chelating Agents; D005456:Fluorescent Dyes; D012235:Rhodamines; C026188:rhodamine 6G; D007501:Iron