A rhodamine-B-based turn-on fluorescent sensor for biological iron(III)

Author(s)

Bordini, Jeane ^[1] ; Calandreli, Ivy ^[1] ; Silva, Gisdelia O. ^[1] ; Ferreira, Kleber Q. ^[1] ; Leitao-Mazzi, Denise P. S. ^[2] ; Espreafico, Enilza M. ^[2] ; Tfouni, Elia ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Biol Celular & Mol & Bioagentes Patogen, BR-14040901 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Inorganic Chemistry Communications; v. 35, p. 255-259, SEP 2013.
• Web of Science Citations: 22

Abstract

Rhodenal, a turn-on fluorescent sensor for iron, derived from rhodamine-B, was synthesized and characterized. Its electronic absorption spectrum in ethanol has bands at 410 (epsilon = 500 cm(-1) mol(-1) L), 316 (epsilon = 14 x 10(3) cm(-1) mol(-1) L), and 272 nm (epsilon = 32 x 10(3) cm(-1) mol(-1) L), and it is pH sensitive with two pK(a) values (1.2 and 2.8). It reacts promptly with Fe3+, with a pesudo-first order rate constant of 1 x 10(3) s(-1), with an equilibrium constant of 1.3 x 10(6) mol(-1) L, forming a violet complex (lambda(max) = 540 nm) with a fluorescent emission at 582 nm, with a higher sensitivity and selectivity compared to those of Fe2+, Ba2+, Al3+, K+, Ca2+, Ni2+, Co2+, Cd2+, Cr3+, Hg2+, Mg2+, Mn2+, Na+, or Cu2+. Biological assays with B16-F10 showed high permeability of plasma membrane to rhodenal and, according to confocal microscopy results, the fluorescent source originated from within the cell revealed iron pools within cytoplasmic and nuclear sub-compartments, making rhodenal a very good prospective Fe3+ sensor, in aqueous solution and especially for biological iron pool detection. (C) 2013 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 06/53266-4 - Chemistry, photochemistry and biological applications of ruthenium complexes with nitric oxide and related species. From solution to materials
• Grantee: Elia Tfouni
• Support Opportunities: Research Projects - Thematic Grants