Three colorimetric and off–on fluorescent chemosensors for Fe³⁺ in aqueous media

Abstract

Three Rhodamine B derivatives were synthesized and characterized by ESI-MS, NMR, HR-MS and IR. The probes exhibit high selectivity and sensitivity towards Fe(3+) over other metal ions in CH3CN-water. Upon the addition of Fe(3+), the spirocyclic ring of the probe was opened and a significant enhancement of visible color and fluorescence within the range of 540-700 nm was observed. The colorimetric and fluorescent response to Fe(3+) can be conveniently detected even by the naked eye, which provides a facile method for the visual detection of Fe(3+). Job's plot, fluorescence titration and MS indicated the formation of 1:2 complexes between the probes and Fe(3+). The reversibility of the reaction establishes the potential of these probes as chemosensors for Fe(3+) detection.

Optical Detection of Fe3+ Ions in Aqueous Solution with High Selectivity and Sensitivity by Using Sulfasalazine Functionalized Microgels

“…Efficient chemical sensors are highly desired for the detection of Fe 3+ ions in aqueous solutions. Efforts are devoted to develop chemical sensors with the use of fluorophores and metal nanoparticles [6] like rhodamine-based chemical sensors [7], fluorescent chemosensors [8], quantum dots [9], and so on. For example, Wei et al [10] reported a PEGylated amphiphilic polymer (C 18 PMH-mPEG) modified core-shell upconversion nanoparticles (mPEG-UCNPs) for highly sensitive and selective detection of Fe 3+ ions in aqueous solution with the detection limit of 89.6 nM.…”

“…With the addition of Fe 3+ ions, the fluorescence of FS1 was “turn-on”, which exhibited high selectivity against the influence of other heavy metal ions with a detection limit of 0.1 μM for Fe 3+ ions. However, most of the above-mentioned chemical sensors required complicated and time consuming synthetic techniques, which might be not available for routine analysis [6,7,8,9,10,11,12]. Therefore, it is needed and worthy to further develop simple, low-cost, efficient, yet robust chemical sensors for the detection of Fe 3+ ions in aqueous solutions.…”

A dual functional probe for “turn-on” fluorescence response of Pb2+and colorimetric detection of Cu2+based on a rhodamine derivative in aqueous media

“…The carbonyl peak of the spirolactum ring (1716 cm −1 ) disappeared after adding Cu 2+ , which suggested that the carbonyl "O" atom was involved in the coordination with Cu 2+ . 32 This is key to the spiro ringopening and absorbance enhancement of the rhodamine dyes. 14e The peak at 1120 cm −1 corresponding to the stretching vibration of the N-O-bond shifted to a higher frequency (1138 cm −1 ) upon interaction with Cu 2+ , indicating that the hydroxamate "O" atom coordinated with Cu 2+ .…”