title: Selective colorimetric and fluorescence 'turn-on' sensor for Ag+and in-situ sensing of CN-(off-on-off) via displacement approach.
abstract: In this contemporary work we designed and synthesized a simple tetra dentate Schiff base, which displays colorimetric and fluorescence "turn on" sensing behavior towards Ag+in aqueous DMF (50%) solution. Benesi Hildebrand-plot reveals 1:2 binding mode between probe and Ag+with limit of detection down to 1.12μM. Cyclic voltammograms exhibits high anodic shift with Ag+due to the charge transfer from ligand to metal ion. The binding mode was proved by NMR titrations, FE-SEM elemental analysis & advance DFT calculation. Additionally, the subsequent Ag+-complex also shows an extremely selective response to CN-among other anions due to the displacement of Ag+via CN-, forming [Ag(CN)x]-species into the medium. Probe was used as coated paper test strip which served as mini colorimetric device for detection of Ag+and CN-.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Roorkee, India.
authors.forename: Nirma
authors.initials: N
authors.lastname: Maurya
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Roorkee, India.
authors.forename: Shubhrajyotsna
authors.initials: S
authors.lastname: Bhardwaj
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Roorkee, India. Electronic address: akscyfcy@iitr.ernet.in.
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Singh
mesh_terms: D003124:Colorimetry; D003486:Cyanides / Q000737:chemistry*; D055664:Electrochemical Techniques; D005456:Fluorescent Dyes / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D057230:Limit of Detection; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D011789:Quantum Theory; D012545:Schiff Bases / Q000737:chemistry; D012834:Silver / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D013818:Thermogravimetry
chemical_list: D003486:Cyanides; D005456:Fluorescent Dyes; D007477:Ions; D012545:Schiff Bases; D012834:Silver
keywords: Ag(+); CN(−); Cyclic voltammogram; DFT; NMR titration; Sensor