Synthesis and photophysical properties of colloids fabricated by the layer-by-layer polyelectrolyte assembly onto Eu(III) complex as a core

The luminescent colloids have been synthesized through the layer-by-layer assembly of poly(sodium 4-styrenesulfonate) (PSS) and polyethyleneimine (PEI) onto the luminescent core. The latter has been obtained by the reprecipitation of complex Eu[(TTA)31] (where TTA− and 1 are thenoyltrifluoroacetonate and 2-(5-chlorophenyl-2-hydroxy)-2-phenylethenyl-bis-(2-methoxyphenyl)phosphine oxide, respectively) from organic solvent to aqueous solution. The variation of Eu(III) complexes indicates the role of the complex core in the development of such core–shell colloids. Complex Eu[(TTA)31] is most convenient precursor of Eu-doped luminescent nanocomposites. The fluorometric measurements at each step of the layer-by-layer polyelectrolyte assembly onto Eu[(TTA)31] core, at various pHs and additives reveal the quenching of Eu-centered luminescence as a result of the interfacial interaction of the core and the dye. The AFM images and electrochemical behavior of PSS–(PEI–PSS)n–Eu[(TTA)31] colloids deposited on the surface indicate the stability of the polyelectrolyte multilayer in the dried state.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The core–shell colloids exhibiting Eu3+ centered luminescence were synthesized through LbL polyelectrolyte assembly onto Eu3+ complex core. ► The ligand environment of Eu3+ affects luminescent and colloidal properties of the core–shell colloids. ► The exterior polyelectrolyte layer greatly affects the electrochemical behavior of the core–shell colloids. ► The quenching of Eu3+ centered luminescence results from the interfacial interactions with dye anions. ► The quenching effect depends on the charge of the exterior layer and the number of polyelectrolyte layers.