title: Optimizing the Electron-Withdrawing Character on Benzenesulfonyl Moiety Attached to a Glyco-Conjugate to Impart Sensitive and Selective Sensing of Cyanide in HEPES Buffer and on Cellulose Paper and Silica Gel Strips.
abstract: Dansyl-derivatized, triazole-linked, glucopyranosyl conjugates, (5F)LOH, (2F)LOH, (1F)LOH, and (0F)LOH were synthesized and characterized. While the (5F)LOH acts as a molecular probe for CN(-), (2F)LOH, (1F)LOH, and (0F)LOH acts as control molecules. The reactivity of CN(-) toward (5F)LOH has been elicited through the changes observed in NMR, ESI MS, emission, and absorption spectroscopy. The conjugate (5F)LOH releases a fluorescent product upon reaction by CN(-) in aqueous acetonitrile medium by exhibiting an ∼125-fold fluorescence enhancement even in the presence of other anions. Fluorescence switch-on behavior has been clearly demonstrated on the basis of the nucleophilic substitution reaction of CN(-) on (5F)LOH. A minimum detection limit of (2.3 ± 0.3) × 10(-7) M (6 ± 1 ppb) was shown by (5F)LOH for CN(-) in solution. All the other anions studied showed no change in the fluorescence emission. The utility of (5F)LOH has been demonstrated by showing its reactivity toward CN(-) on a thin layer of silica gel as well as on Whatman No. 1 cellulose filter paper strips. The role of glucose moiety and the penta-fluorobenzenesulfonyl reactive center present in (5F)LOH in the selectivity of CN(-) over other anions has been demonstrated by fluorescence, absorption and thermodynamics study. Similar studies carried out with the control molecules showed no selectivity for CN(-). The mechanistic aspects of the reactivity of CN(-) toward (5F)LOH were supported by DFT computational study.
authors.affiliation: Bioinorganic Laboratory, Department of Chemistry, Indian Institute of Technology Bombay , Mumbai, Powai, Mumbai 400 076, India.
authors.forename: Sivaiah
authors.initials: S
authors.lastname: Areti
authors.affiliation: Bioinorganic Laboratory, Department of Chemistry, Indian Institute of Technology Bombay , Mumbai, Powai, Mumbai 400 076, India.
authors.forename: Sateesh
authors.initials: S
authors.lastname: Bandaru
authors.affiliation: Bioinorganic Laboratory, Department of Chemistry, Indian Institute of Technology Bombay , Mumbai, Powai, Mumbai 400 076, India.
authors.forename: Deepthi S
authors.initials: DS
authors.lastname: Yarramala
authors.affiliation: Bioinorganic Laboratory, Department of Chemistry, Indian Institute of Technology Bombay , Mumbai, Powai, Mumbai 400 076, India.
authors.forename: Chebrolu Pulla
authors.initials: CP
authors.lastname: Rao
mesh_terms: D001593:Benzyl Compounds / Q000737:chemistry*; D002021:Buffers; D002482:Cellulose / Q000737:chemistry*; D003486:Cyanides / Q000032:analysis*; D004583:Electrons; D006027:Glycosides / Q000737:chemistry*; D006531:HEPES / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010209:Paper; D058428:Silica Gel / Q000737:chemistry*
chemical_list: D001593:Benzyl Compounds; D002021:Buffers; D003486:Cyanides; D006027:Glycosides; D058428:Silica Gel; D002482:Cellulose; D006531:HEPES