Determination of Trace Terbium(III) with N, N, N′-Tri(3-indolemethanal)triaminotriethylamine Based on a New Fluorescence Enhancement System

Abstract

Because they have long fluorescence lifetimes and their excited states have strong fluorescence emission, europium(III) and terbium(III) have extensive applications in biological medicine, especially in the fluorescence imagery cancer radiation treatment, 1 fluorescence mark, 2 and fluorescence analysis. 3 The bioactivity and magnetic performance of Schiff bases and their complexes with rare earth ions have been studied extensively. However, their fluorescence properties have rarely been studied due to their low luminescence. 4,5 So far, chemists have realized that it is essential to design appropriate ligands to optimize the luminescence properties of lanthanide ions by facilitating the well-known light conversion process, which that show to be efficient ligand-to-metal energy-transfer process (antenna effect). Recently, we designed a series of Schiff-base ligands having both selective abilities to coordinate lanthanide ions and enhancing their luminescence by providing proper conjugate absorption groups suitable for energy transfer, which could be used as a luminescent device. In the present work, we designed and synthesized a new and doubly functionalized Schiff-base ligand with a tripodal structure, (N,N′,N″-tri(3-indolemethanal)triaminotriethylamine (TTAIM)), and studied the fluorescence properties of the terbium(III) complex with the new ligand. We found that the Tb 3+ complex with TTAIM can emit intrinsic spectrum of Tb 3+ under excitation of ultraviolet light.Fluorescence enhancement in the field of analytical determination of rare earth elements has for a long time attracted much interest among scientists because of its lower detection limit and higher sensitivity. Phen, EDTA, TTA and TOPO etc., are currently being used as secondary ligands in fluorescence enhancement. 6-8 However, in our recent studies, it was found that NaAc could also strongly enhance the luminescence of Tb 3+ with TTAIM by about two orders of magnitude. Other reagents, such as HMTM, bipy, TBP, tris, sodium tartrate, TOPO, sodium citric acid, NH4Cl, NaH2PO4 and Na2HPO4, do not have the same effect as NaAc, and some of them even slow quenching of the fluorescence of Tb 3+. A further investigation found that dimethyl sulfoxide (DMSO) could enhance the fluorescence intensity of the Tb-TTAIMNaAc system by about 16 fold. Although hundreds of ligands have been used in the fluorescence enhancement field for the determination of lanthanide(III) ions, with some of them achieving low limits of detection, the enhancement effects of NaAc on Schiff bases ligands, up to now, has not been reported. Thus, the phenomenon is unusual. It can be exploited for the development of a new method for the determination of Tb 3+ . The advantages of the method over well-established current ones 9 are (a) high sensitivity and selectivity, (b) rapid reaction time (< 1 min at room temperature), (c) high stability ( 2 h), and (d) simple procedures. Then, the synthesized ligand TTAIM was used to investigate the phenomenon in detail. Experimental ApparatusCarbon, nitr...

Synthesis, spectroscopic characterization and antibacterial activities of three Schiff bases derived from dehydroacetic acid with various substituted anilines

“…Escherichia coli (ATCC 25922), and Pseudomonas aureginosa (ATCC 10197) by the agar well diffusion method [6,7,14,15].…”

“…Schiff bases have been reported to be potential anticancer drugs [4]. The azomethine linkage of the Schiff bases is responsible for various antibacterial, antifungal, herbicidal, clinical and analytical activities [5,6]. Schiff base ligands that contain strong donor sites like phenoxo oxygen atoms and imine nitrogen atoms are brilliant for analytical and biological applications [7,8].…”

Determination of terbium in phosphate rock by Tb3+-selective fluorimetric optode based on dansyl derivative as a neutral fluorogenic ionophore

“…In recent years a number of: isotope dilution mass spectrometry, neutron activation analysis [18,19], X-ray fluorescence spectrometry [20], flow injection analysis [21], fluorescence enhancement [22,23], Raman spectrometry [24], capillary zone electrophoresis [25], and fluorescence methods [26] have been reported in literature for the selective and sensitive determination of Tb 3+ ions. Although these methods are sensitive and accurate, most require a tedious sample pre-treatment (e.g.…”

Novel selective optode membrane for terbium ion based on fluorescence quenching of the 2-(5-(dimethylamino) naphthalen-1-ylsulfonyl)-N-henylhydrazinecarbothioamid

“…In recent years a number of techniques including isotope dilution mass spectrometry, neutron activation analysis, X-ray fluorescence spectrometry [22][23][24], flow injection analysis [25], fluorescence enhancement [26,27], raman spectrometry [28], capillary zone electrophoresis [29], fluorescence methods [30] and electrochemical methods [31,32] have been reported in literature for the selective and sensitive determination of Tb(III) ions. Although these methods are sensitive and accurate, most require a tedious sample pre-treatment (e.g.…”