title: Highly sensitive colorimetric detection of Hg(II) and Cu(II) in aqueous solutions: from amino acids toward solid platforms.
abstract: A chemosensor (NBD-H) based on an amino acid with 7-nitro-2,1,3-benzoxadiazole was used for selective detection of Hg(II) and Cu(II) among 15 metal ions in aqueous solutions by a colorimetric change. NBD-H sensitively differentiated Hg(II) and Cu(II) in aqueous solutions by a color change; a pink color for Hg(II) and an orange color for Cu(II). NBD-H showed nanomolar detection limits for Hg(II) (176 nM, R2 = 0.996) and Cu(II) (163 nM, R2 = 0.996). The detection limit for Cu(II) was much lower than the maximum allowable level of Cu(II) in drinking water recommended by the U.S. EPA. The binding mode study showed that deprotonation of the NH group of NBD-H played a critical role in the binding and sensing of metal ions. NBD-H immobilized on PEG-PS resin maintained the potent binding affinity and sensing ability for the metal ions. The resin with NBD-H was recyclable for the detection of metal ions in 100% aqueous solutions.
authors.affiliation: Bioorganic Chemistry Lab, Center for Design and Applications of Molecular Catalysts, Department of Chemistry and Chemical Engineering, Inha University, Incheon, 402-751, South Korea. leekh@inha.ac.kr.
authors.forename: Jooyoung
authors.initials: J
authors.lastname: Park
authors.forename: Byunggyu
authors.initials: B
authors.lastname: In
authors.forename: Lok Nath
authors.initials: LN
authors.lastname: Neupane
authors.forename: Keun-Hyeung
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D001393:Azoles / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods*; D003300:Copper / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008628:Mercury / Q000032:analysis*; D015394:Molecular Structure; D009578:Nitrobenzenes / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: C510797:7-nitrobenz-2-oxa-1,3-diazol-4-yl; D000596:Amino Acids; D001393:Azoles; D005456:Fluorescent Dyes; D009578:Nitrobenzenes; D012117:Resins, Synthetic; D014867:Water; D003300:Copper; D008628:Mercury