Dye-Polyelectrolyte Layer-by-Layer Self-Assembled Materials: Molecular Aggregation, Structural Stability, and Singlet Oxygen Photogeneration

MARTIN MIRENDA; CRISTIAN A. STRASSERT; LELIA E. DICELIO; ENRIQUE SAN ROMÁN

ACS APPLIED MATERIALS & INTERFACES

AMER CHEMICAL SOC

Año: 2010 vol. 2 p. 1556 - 1560

1944-8244

The interaction of rose Bengal (RB) and fluorescein (FL) with poly[diallyldimethylammonium] chloride (PDDA) was studied in layer-by-layer self-assembled thin films and in solution. The spectroscopic behavior is explained in terms of dye dye, dye polyelectrolyte, and in solution, dye solvent interactions. A correlation among dye hydrophobicity, aggregation tendency, polymer folding in solution, and the stability of self-assembled films is obtained. In spite of the very high dye concentration, RB-PDDA multilayer thin films are able to photogenerate singlet molecular oxygen, as demonstrated by chemical monitoring and IR phosphorescence detection.