Host guest hybrid materials and nanostructured supramolecular systems for photonic and biophotonic applications

Abstract

At the Laboratory of Spectroscopy of Functional Materials (LEMAF) in IFSC/USP, we carry out interdisciplinary research in the field optical and luminescent materials for photonic and biophotonic applications. Among the targeted materials are: 1) Glasses and glass ceramics doped with trivalent rare earth ions TR3+ for scintillators, solar concentrators and sensors; 2) Host-guest hybrids based on emissive guest molecules immobilized in mesoporous hosts and photoresponsive supramolecular systems towards applications in bioimaging, photodynamic therapy, biosensors, and lighting devices. This project aims at realize significant progress in line (2) through a team of 6 directly involved researchers (3PDs, 2DRs, 1IC) and solid collaborations in Brazil and abroad. We propose the production, characterization and, whenever feasible, development of prototypes based on: i) Films and bulk samples of silicate and organo-silicate matrices produced by sol-gel and loaded with the triplet emitting complexes of Ir(III) e Pt(II) displaying high quantum yield from the blue to the red, in concentrations optimized to result in maximum molecular dispersion or aggregation, aiming at white light generation and organic solar cell conversion; ii) Nanoparticles of NaYF4 doped with Er3+/Yb3+ and Tm3+/Yb3+ operating by upconversion (UCNPs) associated to species that are susceptible to resonant energy transfer (LRET), aiming at the development of paper sensors (micropads) for pathogenic bacteria; iii) Supramolecular nanostructures based on UCNPs decorated with cyclodextrin and azobenzene (AZO) molecules, in the presence of Au NPs, aiming at evaluating the luminescent response by exposure to the plasmon effect that might become available or be prevented by the conformational cis-trans photo-responsiveness of the AZO "switch" leading to assembly/disassembly of the system; iv) CdTe and CdS quantum dots for higher order harmonic generation via plasmon induced by femtosecond laser. (AU)