In the photo-antenna effect, electrons in this block are excited when a pendant chromophore absorbs light. For 10 points each:
[10e] Lanthanides luminesce because their valence electrons lie in a subshell denoted by the number 4 and what letter?
ANSWER: f [or f-block; or f electrons; or 4f subshell]
[10m] Once it’s conjugated to an antenna, this rare earth metal makes an excellent phosphorescent red label for microscopy and immunoassays. This most reactive lanthanide is at the center of most NMR shift reagents.
ANSWER: europium [or Eu]
[10h] Because of its phosphorescence, a europium cryptate is the typical donor for this type of sensitive homogeneous FRET. Often abbreviated to two letters, this assay condition means that the donor fluorophore decays slowly compared to the duration of the excitation pulse.
ANSWER: time-resolved fluorescence [or TR; or TR-FRET or TR-Förster resonance energy transfer]
<S, Chemistry>