Rational design and evaluation of the sensing mechanism of a europium( iii )-based luminescent turn-ON chemosensor for citrate

-sphere in Eu.1 suppresses the nonradiative vibrational energy transfer (VET), resulting in enhanced TRL from the f-f transitions, and thus acts as a reversible, selective and sensitive turn-ON sensor at the ppb level of citrate using both the TRL intensity and lifetime-based modalities.