Effect of silica coating and further silica surface decoration by phospholipid bilayer on quenching of Tb(III) complexes by adrenochrome

Abstract

© 2015 Elsevier B.V. Abstract The present report introduces regularities and mechanisms of Tb(III)-centered luminescence quenching by adrenochrome for Tb(III)-p-sulfonatothiacalix[4]arene complexes in the aqueous solutions and the same complexes doped into silica nanoparticles. The choice of adrenochrome (the oxidized form of adrenaline) as quencher originates from its quenching effect on the Tb(III)-centered luminescence, which discriminates it from adrenaline and dopamine. The quenching through dynamic mechanism of the Tb(III) complexes in the solutions results from their concentration induced collision with adrenochrome molecules. The quenching of the Tb(III)-doped silica nanoparticles also occurs through dynamic mechanism, although it is insignificant due to the shielding effect of the silica surface. The inclusion of the Tb(III)-doped silica nanoparticles into phospholipid bilayers influences the quenching of the Tb(III)-centered luminescence by adrenochrome due to its binding with the bilayers deposited onto silica nanoparticles.