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The triplet spectra and dynamics in two types of oligomeric films deposited by thermal evaporation and spin coating techniques are described. The results demonstrated that even minor changes in molecular packing related to density and interaction could lead to large modification in triplet dynamics.

This work reports on the use of protein engineering as a versatile tool to rationally design metal-binding proteins for the synthesis of highly photoluminescent protein-stabilized gold nanoclusters (Prot-AuNCs). The use of a single repeat protein scaffold allowed the incorporation of a set of designed metal-binding sites to understand the effect of the metal-coordinating residues and the protein environment on the photoluminescent (PL) properties of gold nanoclusters (AuNCs). The resulting Prot-AuNCs, synthesized by two sustainable procedures, showed size-tunable color emission and outstanding PL properties. In a second stage, tryptophan (Trp) residues were introduced at specific positions to provide an electron-rich protein environment and favor energy transfer from Trps to AuNCs. This modification resulted in improved PL properties relevant for future applications in sensing, biological labeling, catalysis, and optics.

A novel gas sensing mechanism exploiting lanthanide luminescence modulation upon NO 2 adsorption is demonstrated here. Two isostructural lanthanide-based metal-organic frameworks (MOFs) are used, including an amino group as the sensitive recognition center for NO 2 molecules. The transfer of energy from the organic ligands to Ln is strongly dependent on the presence of NO 2 , resulting in an unprecedented photoluminescent sensing scheme. Thereby, NO 2 exposition triggers either a reversible enhancement or a decrease in the luminescence intensity, depending on the lanthanide ion (Eu or Tb). Our experimental studies combined with density functional theory and complete active space self-consistent field calculations provide an understanding of the nature and effects of NO 2 interactions within the MOFs and the signal transduction mechanism.