EuroTracker (R) dyes: design, synthesis, structure and photophysical properties of very bright europium complexes and their use in bioassays and cellular optical imaging

The development of the brightest luminescent europium(III) complexes is traced, including analysis of the C3-symmetric core complex based on a functionalized triazacyclononane and identification of the most suitable strongly absorbing chromophore. Strategies for the synthesis of the complexes, including enantiopure analogues, are outlined and opportunities for applications in time-resolved microscopy and spectral imaging emphasised. Practicable examples are introduced, including selective organelle staining for cellular optical imaging at 65 nm resolution and the development of new bioassays using time resolved FRET methods

EuroTracker dyes: highly emissive europium complexes as alternative organelle stains for live cell imaging

Nine very bright europium(III) complexes with different macrocyclic ligands have been prepared that exhibit excellent cell uptake behaviour and distinctive sub-cellular localisation profiles, allowing the use of fluorescence microscopy and time-gated spectral imaging to track their fate in cellulo. Their use as cellular imaging stains is described for the selective illumination of mitochondria, lysosomes or the endoplasmic reticulum of various mammalian cell types

Supplementary information files for Time-resolved luminescence detection of peroxynitrite using a reactivity-based lanthanide probe

Supplementary files for article Time-resolved luminescence detection of peroxynitrite using a reactivity-based lanthanide probe. Peroxynitrite (ONOO−) is a powerful and short-lived oxidant formed in vivo, which can react with most biomolecules directly. To fully understand the roles of ONOO− in cell biology, improved methods for the selective detection and real-time analysis of ONOO− are needed. We present a water-soluble, luminescent europium(III) probe for the rapid and sensitive detection of peroxynitrite in human serum, living cells and biological matrices. We have utilised the long luminescence lifetime of the probe to measure ONOO− in a time-resolved manner, effectively avoiding the influence of autofluorescence in biological samples. To demonstrate the utility of the Eu(III) probe, we monitored the production of ONOO− in different cell lines, following treatment with a cold atmospheric plasma device commonly used in the clinic for skin wound treatment

Microscopic Visualization of Metabotropic Glutamate Receptors on the Surface of Living Cells Using Bifunctional Magnetic Resonance Imaging Probes

A series of bimodal metabotropic glutamate-receptor targeted MRI contrast agents has been developed and evaluated, based on established competitive metabotropic Glu receptor subtype 5 (mGluR₅) antagonists. In order to directly visualize mGluR₅ binding of these agents on the surface of live astrocytes, variations in the core structure were made. A set of gadolinium conjugates containing either a cyanine dye or a fluorescein moiety was accordingly prepared, to allow visualization by optical microscopy <i>in cellulo</i>. In each case, surface receptor binding was compromised and cell internalization observed. Another approach, examining the location of a terbium analogue via sensitized emission, also exhibited nonspecific cell uptake in neuronal cell line models. Finally, biotin derivatives of two lead compounds were prepared, and the specificity of binding to the mGluR₅ cell surface receptors was demonstrated with the aid of their fluorescently labeled avidin conjugates, using both total internal reflection fluorescence (TIRF) and confocal microscopy

Appendix A. Sites at which neighbor-removal competition experiments were conducted with Centaurea stoebe as the target.

Sites at which neighbor-removal competition experiments were conducted with Centaurea stoebe as the target