title: A highly selective redox, chromogenic, and fluorescent chemosensor for Hg2+ in aqueous solution based on ferrocene-glycine bioconjugates.
abstract: The synthesis, electrochemical, optical, and metal-cation-sensing properties of ferrocene-glycine conjugates C(30)H(38)O(8)N(8)Fe (2) and C(20)H(24)O(4)N(4)Fe (3) have been documented. Both compounds 2 and 3 behave as very selective redox (ΔE(1/2) = 217 mV for 2 and ΔE(1/2) = 160 mV for 3), chromogenic, and fluorescent chemosensors for Hg(2+) cations in an aqueous environment. The considerable changes in their absorption spectra are accompanied by the appearance of a new low-energy peak at 630 nm (2, ε = 1600 M(-1) cm(-1); 3, ε = 822 M(-1) cm(-1)). This is also accompanied by a strong color change from yellow to purple, which allows a prospective for the "naked eye" detection of Hg(2+) cations. These chemosensors present immense brightness and fluorescence enhancement (chelation-enhanced fluorescence = 91 for 2 and 42 for 3) following Hg(2+) coordination within the limit of detection for Hg(2+) at 7.5 parts per billion.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India.
authors.forename: Arunabha
authors.initials: A
authors.lastname: Thakur
authors.forename: Sinjinee
authors.initials: S
authors.lastname: Sardar
authors.forename: Sundargopal
authors.initials: S
authors.lastname: Ghosh
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D003116:Color; D003300:Copper / Q000032:analysis / Q000737:chemistry; D004563:Electrochemistry; D005296:Ferrous Compounds / Q000737:chemistry*; D005998:Glycine / Q000737:chemistry*; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D000075163:Metallocenes; D010084:Oxidation-Reduction; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity; D014867:Water / Q000737:chemistry*
chemical_list: D005296:Ferrous Compounds; D000075163:Metallocenes; D012996:Solutions; D014867:Water; D003300:Copper; D008628:Mercury; D005998:Glycine; C004998:ferrocene