title: Coumarin-based fluorescent probes for dual recognition of copper(II) and iron(III) ions and their application in bio-imaging.
abstract: Two new coumarin-based "turn-off" fluorescent probes, (E)-3-((3,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS1) and (E)-3-((2,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS2), were synthesized and their detection of copper(II) and iron(III) ions was studied. Results show that both compounds are highly selective for Cu²⁺ and Fe³⁺ ions over other metal ions. However, BS2 is detected directly, while detection of BS1 involves a hydrolysis reaction to regenerate 3-amino-7-hydroxycoumarin (3) and 3,4-dihydroxybenzaldehyde, of which 3 is able to react with copper(II) or iron(III) ions. The interaction between the tested compounds and copper or iron ions is associated with a large fluorescence decrease, showing detection limits of ca. 10⁻⁵ M. Preliminary studies employing epifluorescence microscopy demonstrate that Cu²⁺ and Fe³⁺ ions can be imaged in human neuroblastoma SH-SY5Y cells treated with the tested probes.
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 7800024, Chile. ojgarciab@ug.uchile.cl.
authors.forename: Olimpo
authors.initials: O
authors.lastname: García-Beltrán
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 7800024, Chile. bcassels@u.uchile.cl.
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Cassels
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 7800024, Chile. claudio.perez.mendez@gmail.com.
authors.forename: Claudio
authors.initials: C
authors.lastname: Pérez
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 7800024, Chile. npaz81@hotmail.com.
authors.forename: Natalia
authors.initials: N
authors.lastname: Mena
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 7800024, Chile. mnunez@uchile.cl.
authors.forename: Marco T
authors.initials: MT
authors.lastname: Núñez
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 7800024, Chile. natalia.dpma@gmail.com.
authors.forename: Natalia P
authors.initials: NP
authors.lastname: Martínez
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 7800024, Chile. ppavezg@uc.cl.
authors.forename: Paulina
authors.initials: P
authors.lastname: Pavez
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 7800024, Chile. mealiaga@uc.cl.
authors.forename: Margarita E
authors.initials: ME
authors.lastname: Aliaga
mesh_terms: D045744:Cell Line, Tumor; D058948:Cell Tracking; D003300:Copper / Q000737:chemistry; D003374:Coumarins / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes; D006801:Humans; D006861:Hydrogen Peroxide; D007477:Ions / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D057054:Molecular Imaging / Q000379:methods*
chemical_list: D003374:Coumarins; D005456:Fluorescent Dyes; D007477:Ions; D003300:Copper; C030123:coumarin; D006861:Hydrogen Peroxide; D007501:Iron