title: Chromo/Fluorogenic Detection of Co(2+), Hg(2+) and Cu(2+) by the Simple Schiff Base Sensor.
abstract: Herein, we reported the ditriazole Schiff base derivative 1 and evaluated its photophysical properties on induction of varieties of metal ions including Na(+), Ag(+), Ni(2+), Mn(2+), Pd(2+), Co(2+), Hg(2+), Cu(2+), Pb(2+), Cd(2+), Zn(2+), Sn(2+), Fe(2+), Fe(3+), Cr(3+) and Al(3+), in order to figure out its potential as ion sensor. The ligand 1 exhibited the strong colorimetric change in the reaction solution as well as absorption spectral shifting with the concomitant appearance of well-defined isosbestic points only upon Co(2+), Hg(2+) and Cu(2+) addition corroborates its applicability as multichannel ion detector. The different extent of spectral shifting as well as unique chromogenic change in the probe solution upon Co(2+), Hg(2+) and Cu(2+) introduction can be used as the discrimination tool for these metal ions. The ligand-metal binding stoichiometry was assessed by their optical response which was further supported by the FT-IR, NMR and mass spectrometric analysis. The association constant and the detection limits of the ligand toward Co(2+), Hg(2+) and Cu(2+) ions were calculated to be 1.52 × 10(-8), 3.26 × 10(-9), 1.16 × 10(-8) and 3.87 × 10(-10), 5.47 × 10(-11), 8.91 × 10(-11) M, respectively, employing the Benesi-Hilderbrand equation and 3 σ slope(-1) methods. Furthermore, the successive addition of Co(2+), Hg(2+) and Cu(2+) induce the constant decline in the fluorescence emission signal intensity of the probe. The quenching efficiency of the probe upon metallic induction was fitted to the Stern-Volmer equation which yielded the upward curvature in case of all the three metals ions (Co(2+), Hg(2+) and Cu(2+)) when (Io/I-1) was plotted against the quencher concentration indicating the occurrence of both the dynamic and static quenching process in the system with the average Stern-Volmer quenching constant values of 9.25 × 10(-7), 1.14 × 10(-7), 1.829 × 10(-7), respectively.
authors.affiliation: Department of Chemistry, Kongju National University, Gongju, Chungnam, 314-701, Republic of Korea.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Saleem
authors.affiliation: Department of Chemistry, Kongju National University, Gongju, Chungnam, 314-701, Republic of Korea.
authors.forename: Chung Ho
authors.initials: CH
authors.lastname: Khang
authors.affiliation: Biomaterial Research Center, Korea Research Institute of Chemical Technology, PO Box 107, Yuseong, Daejon, 305-600, Republic of Korea.
authors.forename: Moon-Hwan
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Kongju National University, Gongju, Chungnam, 314-701, Republic of Korea. khlee@kongju.ac.kr.
authors.forename: Ki Hwan
authors.initials: KH
authors.lastname: Lee
mesh_terms: D002853:Chromatography, Liquid; D003035:Cobalt / Q000032:analysis*; D003300:Copper / Q000032:analysis*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008628:Mercury / Q000032:analysis*; D012545:Schiff Bases / Q000138:chemical synthesis / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014230:Triazoles / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D012545:Schiff Bases; D014230:Triazoles; D003035:Cobalt; D003300:Copper; D008628:Mercury
keywords: Chromogenic; Fluorescence quenching; Fluorogenic; Isosbestic points; Schiff base