Nickel(ii) and iron(iii) selective off-on-type fluorescence probes based on perylene tetracarboxylic diimide

Abstract

Two novel "turn-on" fluorescent probes with perylene tetracarboxylic diimide (PDI) as the fluorophore and two different di-(2-picolyl)-amine (DPA) groups as the metal ion receptor (PDI-1 and PDI-2) were successfully synthesized with satisfactory yields. PDI-1 exhibited high selectivity toward Ni(2+) in the presence of various other metal cations including Zn(2+), Cd(2+) and Cu(2+) which were expected to interfere significantly. A 1 : 2 stoichiometry was found for the complex formed by PDI-1 and Ni(2+) by a Job's plot and by non-linear least square fitting of the fluorescence titration curves. By introducing an extra diamino ethylene group between DPA and the phenyl bridge, the receptor was modified and the high selectivity of the sensor toward Ni(2+) shifted to Fe(3+). The enhancement factor of the fluorescence response of PDI-2 to Fe(3+) was as high as 138. The binding behavior of the receptors in these two compounds is affected significantly by the PDI fluorophores. Most interestingly, both Ni(2+) and Fe(3+) are paramagnetic metal ions, which are known as fluorescence quenchers and are rarely targeted with "turn-on" fluorescence probes. This result suggests that PDIs are favorable fluorophores for a "turn-on" fluorescence probe for paramagnetic transition metal ions because of their high oxidation potential.

Siderophore-based detection of Fe(iii) and microbial pathogens

“…To date, few turn-on fluorescent detectors for Fe(III) have been reported, 49,72,[110][111][112] making these pyochelin-fluorophore conjugates important contributions to the broad field of metal-ion sensing. Moreover, several of the turn-on Fe(III) sensors reported to date have relatively low affinity (K d ~ 5 -300 µM) and hence high detection limits, which limit practical utility.…”

Off–on switchable chemosensor based on rhodamine armed with morpholine moiety

“…Although significant contributions to the development of spectroscopic sensing for Fe 3+ have been made over the last few decades [14][15][16][17], there have been relatively few fluorescent probes for Fe 3+ which showed "off-on" signal. It might be due to its paramagnetic nature which leads to fluorescence quenching.…”

Spectral studies on benzimidazole-based “bare-eye” probe for the detection of Ni 2+ : Application as a solid state sensor

“…Metal ions are desirable for a proper metabolic activity; though, they are, when in excess, associated to several pathologies. Examples of these are central nervous system disorder, cancer of lungs, nasal cavity, skin allergy, asthma, acute pneumonitis [24][25][26][27][28], Wilson's disease [29], Menkes disease [30], Prion and Alzheimer's diseases, Parkinson's, epilepsy, ischemic stroke and infantile diarrhea, vasodilation and so on [31][32][33][34][35][36].…”