Lanthanide luminescent bioprobes and

The chromophore is directly coordinated to the lanthanide ion (see Figure 10a). Chromophores are thus designed to ensure an efficient positioning of the triplet energy, which would allow the photosensitization of the lanthanide ion, and enclose adequate coordination sites to guarantee a stable complexation of the cation. For further details, Lanthanides Luminescence Applications and Luminescent Bioprobes. 

Multiphoton or two-photon laser scanning microscopy is an alternative to confocal and time-resolved microscopy for bioimaging applications. The principle has been discussed in Lanthanides Luminescence Applications and concerns a two-photon excitation from the simultaneous absorption of two photons in a single quantized event. A bioprobe that normally absorbs ultraviolet light (Xex = 350 nm) can also be excited by two photons of NIR light, at 700 nm (the wavelength is twice that required for one-photon excitation). These two photons must interact simultaneously, which means in a very small lapse time. The instrumentation requires pulse lasers to provide sufficient power, as the photon density must... 

Bioimaging with Lanthanide Luminescent Probes and Bioprobes... 

Extension to the use of multi-photon induced luminescence lanthanide-based bioprobes adds new possibilities and challenges to the field. However, there are even fewer examples of multiphoton lanthanide bioprobes because achieving acceptable quantum yields is fairly difficult in view of the numerous nonradiative deactivation pathways created by a wealth of vibrations, including high energy oscillators located far from the emitting lanthanide ion. 

Ligands Near-Infrared Materials Lanthanides Magnetic Resonance Imaging Luminescent Bioprobes Sensors for Lanthanides and Actinides. 

Some examples are emphasized in the next chapter Lanthanides Luminescence Applications). The luminescence spectra of various lanthanide ions will be given and several applications using luminescent lanthanide complexes will be presented. Luminescent Bioprobes, some practical data and a case of study will be presented. The properties of a series of lanthanide complexes (i.e., with ligands that share a common architectme) will be expUcated both from a physicochemical and from a photophysical point of view. It will be demonstrated that these complexes are highly stable and present interesting photophysical properties, so that their application as bioprobe can be imdertaken. 

Figure 13.27 (Top) Luminescence images of HeLa cells loaded with different concentrations of [Eu2(L62)3] in RPMI-1640 for 7h at 37°C. (Lex = 330nm, Xem >585nm, exposure time 60s). (Middle) Images of HeLa cells loaded with 250 p.M [Eu2(L62)3] (5h at 37°C, exposure time 10 s), then incubated with 40mgmL acridine orange (Xex = 450 90 nm Xem = 515-565 nm, exposure time 10 ms) in PBS (5 min at room temperature). (Bottom) Co-localization experiments cells loaded with 250 p.M [Eu2(L62)3] and 15 mgmL BIODIPY PL LDL (0.5 h, Xex = 470 nm, 2 s exposure time) [77]. (Reproduced from E. Deiters et al., Effect of the length of polyoxyethylene substituents on luminescent bimetallic lanthanide bioprobes, New Journal of Chemistry, 32, 1140-1152, 2008, by permission of The Royal Society of Chemistry (RSC) for the Centre National de la Recherche Scientifique (CNRS) and the RSC.)...

Deiters, E., Song, B., Chauvin, A.S., et al. (2009) Luminescent bimetallic lanthanide bioprobes for cellular imaging with excitation in the visible-Ught range. Chemistry —A European Journal, 15, 885—900. Charbonniere, L.J., Weibel, N., Estoumes, C., et al. (2004) Spatial and temporal discrimination of siUca particles functionalized with luminescent lanthanide markers using time-resolved luminescence microscopy. New Journal of Chemistry, 28, 777—781. 

S. Comby, Luminescent Lanthanide Bioprobes Emitting in the Visible and/or Near-InJiared Ranges Ph. D. dissertation, Ecole Poly technique FedCTale de Lausanne, 2008. 

---