title: Solvent-assisted selective detection of sub-micromolar levels of Cu2+ ions in aqueous samples and live-cells.
abstract: Two new rhodamine–indole conjugates 1 and 2 were synthesized for studying their ability to probe specific metal ions at physiological pH in the presence of other competing metal ions. In non-aqueous medium, probe 1 predominantly binds Cu(2+) ions with considerable interference from Fe(3+) and Ni(2+) ions. However, in aqueous medium, 1 exhibits a higher degree of selectivity for Cu(2+) ions with little interference from Fe(3+) ions, and no interference from Ni(2+) ions. The probe 2, obtained by tethering a triazole moiety with probe 1, selectively binds Cu(2+) ions in aqueous medium even in the presence of other metal ions including Fe(3+) ions. The sensitivity of probe 2 to pH variation and interaction with various amino acids were also investigated. The excellent stability of 2 in physiological pH conditions, non-toxicity, non-interference of amino acids in the detection process, and the remarkable selectivity for Cu(2+) ions in aqueous medium allowed the use of 2 in the imaging of live fibroblast cells treated with Cu(2+).
authors.affiliation: Organic Chemistry Division, CSIR-Central Leather Research Institute, Adyar, Chennai-600 020, India.
authors.forename: Narendra Reddy
authors.initials: NR
authors.lastname: Chereddy
authors.forename: Subramaniyan
authors.initials: S
authors.lastname: Janakipriya
authors.forename: Purna Sai
authors.initials: PS
authors.lastname: Korrapati
authors.forename: Sathiah
authors.initials: S
authors.lastname: Thennarasu
authors.forename: Asit Baran
authors.initials: AB
authors.lastname: Mandal
mesh_terms: D000818:Animals; D002470:Cell Survival; D003300:Copper / Q000032:analysis* / Q000737:chemistry; D051379:Mice; D041681:NIH 3T3 Cells; D012235:Rhodamines / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D014867:Water / Q000032:analysis* / Q000737:chemistry
chemical_list: D012235:Rhodamines; D012997:Solvents; D014867:Water; D003300:Copper