Luminescent lanthanide sensors complexes

Keywords Lanthanide Sensor Sensitized luminescence Dipicolinate Macrocycle Ternary complex Bacterial spore Ancillary ligand Gadolinium break Catecholamine Salicylic acid Salicylurate. 

Figure 13.4 Typical design principle of lanthanide complex-based chemosensors based on binding of an analyte (an) (a) directly influencing the Ln(III) luminescence, (b) influencing photophysical properties of the ligand, and (c) addition of a sensitizing analyte onto a poorly luminescent lanthanide-containing sensor [1]. (Reproduced from J.C.G. Bunzli and C. Piguet, Taking advantage of luminescent lanthanide ions, Chemical Society Reviews, 34, 1048-1077, 2005, by permission of The Royal Society of Chemistry.)...

Lanthanide(III) complexes demand special attention in view of the specific spectra-structure relationship for biological applications, chiral catalysis, molecular magnetism and luminescence. One unique chiral stereochemistry is realized by the combination of labile Ln complexes and weak Na+-fluorocarbon interactionwhich show intense CD (circular dichroism) with variation of Ln(III) and/or M(I) ions to chiroptical spectra-structure relations and an important role in configurational chirality for chemical sensors, NMR shift reagents or chiral catalysis. Trivalent lanthanides are also found to be incorporated into heterobimetallic complexes showing intramolecular energy transfer processes. 

The photophysics of lanthanide complexes has drawn considerable attention in recent years, in part because of the potential applications of lanthanides (sensors, electroluminescent displays, etc.) and several recent reviews highlighting applications of luminescent lanthanide complexes have appeared. A discussion of infrared f-f luminescence of Yb, Nd, and Er in complexes having macrocyclic ligands such as porphyrins, cyclen derivatives, and calixarenes was published by Korovin and Rusakova. " In addition, DaSilva and co-workers describe the development of highly luminescent lanthanide complexes and their application as light-conversion molecular devices. ... 

Although not particularly designed to be a pH-sensitive luminescent probe, Beeby et al. described a phenanthridine-carrying water-soluble Yb complex, in which the photosensitisation mechanism is switched as a functi(m of pH [93], A crown ether-modified neodymium(III) cryptand was proposed for barium ion detection [94], but as with many prototype cation sensors, the probe only works in acetonitrile. Moreover, the complex necessitates ultraviolet excitation, which removes one of the main advantages of using NIR luminescent lanthanide complexes. 

Hauenstein BL, Picemo R, Brittain HG, Nestor JR (1989) Luminescent oxygen sensor based on a lanthanide complex. US Patent 4861727... 

Although several luminescent lanthanide complexes respond to environmental changes such as pH and temperature modifications, biological cage proteins containing lanthanide cations have been developed recently and provide environmental sensors in aqueous media. 

Complexation of TV+ occurred more rapidly and reversibly to induce Tb luminescence changes at pH 6.0 to 8.0 (Figure 16.18a). Apolactoferrin formed a more stable TV+ complex than the apotransferrin complex and its TV+ complex exhibited pH-dependent luminescence behavior at a lower pH. Such pH-dependent luminescence changes were detectable by the naked eye. Since the apotransferrin-Yb + complex permeated into the cell via a transferrin receptor mechanism, incorporating luminescent lanthanide complexes into biological proteins may provide tools for sensors in intracellular environments. 

Parker D, Bretonnifere Y. Luminescent Lanthanide Complexes as Sensors and Imaging Probes. In Bogdanov AAJ, Licha K, editors. Molecular Imaging Springer, Heidelberg 2005. pp. 123-146. 

Halides are negatively charged spherical structures which normally bind to anion receptors in a non-directional fashion. One of the first examples of the use of halides for binding to lanthanide complexes, by direct metal coordination within a coordinatively unsaturated environment, was that of Charbonniere et al. [55] who developed lanthanide complexes of a bis-bipyridine-phosphine oxide ligand (Scheme 6.9a), as luminescent anion sensors for halides. In this design, the bipyridine (bpy) units were expected to coordinate to the... 

The first two chapters of this work cover theoretical and practical aspects of the emission process, the spectroscopic techniques and the equipment used to characterize the emission. Chapter 3 introduces and reviews the property of circularly polarized emission, while Chapter 4 reviews the use of lanthanide ion complexes in bioimaging and fluorescence microscopy. Chapter 5 covers the phenomenon of two-photon absorption, its theory as well as applications in imaging, while Chapter 6 reviews the use of lanthanide ions as chemo-sensors. Chapter 7 introduces the basic principles of nanoparticle upconversion luminescence and its use for bioimaging and Chapter 8 reviews direct excitation of the lanthanide ions and the use of the excitation spectra to probe the metal ion s coordination environment in eoordination compounds and biopolymers. Finally, Chapter 9 describes the formation of heterobimetallic complexes, in whieh the lanthanide ion emission is promoted through the hetero-metal. 

The aim of this chapter is limited to reviewing some recent developments concerning luminescent dendrimers that can play the role of ligands and sensors for luminescent and nonluminescent metal ions, mainly investigated in our laboratories, with particular references to transition metal or lanthanide ions. We will not discuss dendrimers constituted by polypyridine metal complexes [21] and porphyrins [22] since it is outside the scope of the present paper. 

Given their favourable luminescence properties and propensity to coordinate oxy-anions, it is perhaps surprising that complexes of lanthanide(III) ions have received comparatively little attention as anion sensors. 

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