High‐Efficiency FRET Processes in BODIPY‐Functionalized Quantum Dot Architectures
Annamaria Panniello, Mariachiara Trapani, Massimiliano Cordaro, Carlo Nazareno Dibenedetto, R. Tommasi, Chiara Ingrosso, Elisabetta Fanizza, Roberto Grisorio, Elisabetta Collini, Angela Agostiano, Maria Lucia Curri, Maria Angela Castriciano, Marinella Striccoli
Abstract
Efficient FRET systems are developed combining colloidal CdSe quantum dots (QDs) donors and BODIPY acceptors. To promote effective energy transfer in FRET architectures, the distance between the organic fluorophore and the QDs needs to be optimized by a careful system engineering. In this context, BODIPY dyes bearing amino-terminated functionalities are used in virtue of the high affinity of amine groups in coordinating the QD surface. A preliminary QD surface treatment with a short amine ligand is performed to favor the interaction with the organic fluorophores in solution. The successful coordination of the dye to the QD surface, accomplishing a short donor-acceptor distance, provides effective energy transfer already in solution, with efficiency of 76 %. The efficiency further increases in the solid state where the QDs and the dye are deposited as single coordinated units from solution, with a distance between the fluorophores down to 2.2 nm, demonstrating the effectiveness of the coupling strategy.