Luminescent Eu ^{IIIIII and Tb IIIIII Complexes Containing Dopamine Neurotransmitter: Biological Interactions, Antioxidant Activity and Cellular‐Imaging Studies}

摘要

> Two luminescent water‐soluble lanthanide(III) complexes, [Ln(DTPA‐DOPA)(H ₂ O)] ( 1–2 ) where Ln = Eu III ( 1 ), Tb III ( 2 ), formed by reaction with diethylenetriaminepentaacetic acid (DTPA) carrying the neurotransmitter dopamine with catechol functional groups [i.e., DTPA‐bis(3‐hydroxytyramide)], are characterized and their photophysical properties are studied. Strong characteristic red and green luminescence is observed for 1 and 2 upon photoexcitation, followed by efficient energy transfer from dopamine to Ln III , leading to intraconfigurational f – f transitions. They show distinguishable sharp emission bands due to intraconfigurational 5 D ₀ → 7 F _J transitions in Eu III and 5 D ₄ → 7 F _J transitions in Tb III . They exhibit long excited‐state lifetimes [ τ = 0.52 ms ( 1 ) and 0.33 ms ( 2 )] and calculated quantum yields, Φ _overall , of 0.022 ( 1 ) and 0.038 ( 2 ). The luminescent complexes are studied for their antioxidant activity, ability to interact with calf‐thymus DNA (CT‐DNA) and bovine serum albumin (BSA), hydrolytic cleavage of pUC