Quantum yields luminescent 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. 

Encapsulation of the chelates into nanopartieles often results in further improvements of their photophysical properties [219,220]. We have also seen above that relatively modest quantum yields can be compensated by introducing several emitting ions in one probe. This is achieved in luminescent metal-organic frameworks [221] or dendrimeric complexes [214] which then present attractive properties, including multifunctionality and nanoscale processability, for chemical sensors and bioprobes. 

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