Issue 14, 2012

A ratiometric fluorescent chemosensor for iron: discrimination of Fe2+ and Fe3+ and living cell application

Abstract

A newly designed probe, 6-thiophen-2-yl-5,6-dihydrobenzo[4,5]imidazo-[1,2-c] quinazoline (HL1) behaves as a highly selective ratiometric fluorescent sensor for Fe2+ at pH 4.0–5.0 and Fe3+ at pH 6.5–8.0 in acetonitrileHEPES buffer (1/4) (v/v) medium. A decrease in fluorescence at 412 nm and increase in fluorescence at 472 nm with an isoemissive point at 436 nm with the addition of Fe2+ salt solution is due to the formation of mononuclear Fe2+ complex [FeII(HL)(ClO4)2(CH3CN)2] (1) in acetonitrileHEPES buffer (100 mM, 1/4, v/v) at pH 4.5 and a decrease in fluorescence at 412 nm and increase in fluorescence at 482 nm with an isoemissive point at 445 nm during titration by Fe3+ salt due to the formation of binary Fe3+ complex, [FeIII(L)2(ClO4)(H2O)] (2) with co-solvent at biological pH 7.4 have been established. Binding constants (Ka) in the solution state were calculated to be 3.88 × 105 M−1 for Fe2+ and 0.21 × 103 M−1/2 for Fe3+ and ratiometric detection limits for Fe2+ and Fe3+ were found to be 2.0 μM and 3.5 μM, respectively. The probe is a “naked eye” chemosensor for two states of iron. Theoretical calculations were studied to establish the configurations of probe–iron complexes. The sensor is efficient for detecting Fe3+in vitro by developing a good image of the biological organelles.

Graphical abstract: A ratiometric fluorescent chemosensor for iron: discrimination of Fe2+ and Fe3+ and living cell application

Supplementary files

Article information

Article type
Paper
Submitted
22 Feb 2012
Accepted
03 May 2012
First published
07 Jun 2012

Analyst, 2012,137, 3335-3342

A ratiometric fluorescent chemosensor for iron: discrimination of Fe2+ and Fe3+ and living cell application

S. Sen, S. Sarkar, B. Chattopadhyay, A. Moirangthem, A. Basu, K. Dhara and P. Chattopadhyay, Analyst, 2012, 137, 3335 DOI: 10.1039/C2AN35258C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements