title: Tuning of the selectivity of fluorescent peptidyl bioprobe using aggregation induced emission for heavy metal ions by buffering agents in 100% aqueous solutions.
abstract: Smart fluorescent probes of which the detection of specific target molecules can be controlled are attracting remarkable interest. A fluorescent peptidyl bioprobe (1) was rationally synthesized by conjugating tetraphenylethylene, an aggregation-induced emission (AIE) fluorophore with a peptide receptor (AspHis) that acted as hard and intermediate bases. The selective detection of 1 for specific metal ion in 100% aqueous solutions was controlled by the buffering agents with the chelate effect without the change of pH. In distilled water and phosphate buffered aqueous solution at neutral pH, 1 exhibited a selective Off-On response to a soft metal ion, Hg2+among test metal ions by 100-fold enhancement of the emission at 470nm. 1 showed a selective Off-On response (180-fold enhancement) to a hard metal ion, Al3+ions among test metal ions in Tris buffered aqueous solution at neutral pH and Hexamine (hexamethylenetetramine) buffered aqueous solution at acidic pH. The detection limit of 0.46 ppb for Hg2+and 2.26 ppb for Al3+in each condition was lower than the maximum allowable level of the metal ions in drinking water by EPA. This research helps to understand how buffering agents participate in the complex formation and aggregation of fluorescent probes using an AIE process for the selective detection of specific metal ions in aqueous solutions.
authors.affiliation: Bioorganic Chemistry Laboratory, Center for Design and Applications of Molecular Catalysts, Department of Chemistry and Chemical Engineering, Inha University, Incheon 402-751, South Korea.
authors.forename: Lok Nath
authors.initials: LN
authors.lastname: Neupane
authors.affiliation: Bioorganic Chemistry Laboratory, Center for Design and Applications of Molecular Catalysts, Department of Chemistry and Chemical Engineering, Inha University, Incheon 402-751, South Korea.
authors.forename: Gi Won
authors.initials: GW
authors.lastname: Hwang
authors.affiliation: Bioorganic Chemistry Laboratory, Center for Design and Applications of Molecular Catalysts, Department of Chemistry and Chemical Engineering, Inha University, Incheon 402-751, South Korea. Electronic address: leekh@inha.ac.kr.
authors.forename: Keun-Hyeung
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000535:Aluminum / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods*; D002021:Buffers; D005456:Fluorescent Dyes / Q000737:chemistry*; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis; D010455:Peptides / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002021:Buffers; D005456:Fluorescent Dyes; D019216:Metals, Heavy; D010455:Peptides; D014874:Water Pollutants, Chemical; D014867:Water; D000535:Aluminum; D008628:Mercury
keywords: Aggregation-induced emission; Al(3+); Fluorescence; Heavy metal ions; Hg(2+); Probe