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Projeto de investigação
Novo: Advanced water-soluble soft nanomaterials encapsulating luminescent inorganic and organic emitters and hydrophobic drugs as novel nanocarriers: from bioimaging to drug delivery and environmental applications. Antigo: Advanced water-soluble soft nanoparticles encapsulating luminescent PtII and BIII emitters and hydrophobic drugs as novel nanocarriers: from bio-imaging to drug delivery applications.
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Tetra dansylamides substituted cyclen and cyclam macrocycles as fluorescent sensing probes for metal ions and temperature-responsive materials in dopped polymers
Publication . Pereira-Gomes, Inês; Duarte, Frederico Gonçalo do Vale; Dobrikov, Georgi M.; Slavchev, Ivaylo; Kurutos, Atanas; Capelo-Martínez, José Luis; Santos, H. M.; Lodeiro, Carlos; DQ - Departamento de Química; LAQV@REQUIMTE; Elsevier
Two novel tetra-dansyl derivatives incorporating cyclen (1,4,7,10-tetraazacyclododecane) and cyclam (1,4,8,11-tetraazacyclotetradecane) macrocycles have been synthesized, thoroughly characterized, and their photophysical properties examined, both in solution and in the solid state. These compounds exhibit fluorescence emission with quantum yields up to 40 %, varying significantly with different solvents. They also display positive solvatofluorochromic behavior, with emissions ranging from green to yellow colours. Kamlet-Taft studies were conducted to better understand solute-solvent interactions. Furthermore, aggregation-induced emission was observed in solutions with high water content, confirmed via dynamic light scattering. Given the intrinsic properties of these compounds, their potential for environmental remediation was explored through metal ion sensing studies. Compounds L1 and L2 demonstrated high sensitivity to Cu2+ and Hg2+ ions, significantly modulating their emission, with L2 capable of detecting and quantifying Hg2+ concentrations as low as 2–3 μM. Additionally, the solid-state emission of these compounds encouraged an investigation into their potential as temperature sensors. Several doped polymer thin films were fabricated, establishing a linear relationship with temperature beyond their melting point. These findings suggest that these tetra-chromophoric compounds hold promise as molecular thermometers.
Exploring Coumarin-Based Boron Emissive Complexes as Temperature Thermometers in Polymer-Supported Materials
Publication . Pedro, Gonçalo; Duarte, Frederico; Cheptsov, Dmitrii A.; Volodin, Nikita Yu.; Ivanov, Ivan V.; Santos, Hugo M.; Capelo-Martínez, José Luis; Cuerva, Cristián; Oliveira, Elisabete; Traven, Valerii F.; Lodeiro, Carlos; DQ - Departamento de Química; LAQV@REQUIMTE; MDPI - Multidisciplinary Digital Publishing Institute
Three coumarin-based boron complexes (L1, L2 and L3) were designed and successfully incorporated into polymeric matrixes for evaluation as temperature probes. The photophysical properties of the complexes were carried out in different solvents and in the solid state. In solution, compound L1 exhibited the highest fluorescence quantum yield, 33%, with a positive solvatochromism also being observed on the absorption and emission when the polarity of the solvent increased. Additionally in the presence of anions, L1 showed a colour change from yellow to pink, followed by a quenching in the emission intensity, which is due to deprotonation with the formation of a quinone base. Absorption and fluorescence spectra of L1 were calculated at different temperatures by the DFT/B3LYP method. The decrease in fluorescence of compound L1 with an increase in temperature seems to be due to the presence of pronounced torsional vibrations of the donor and acceptor fragments relative to the single bond with C(carbonyl)-C (styrene fragment). L1, L2 and L3, through their incorporation into the polymeric matrixes, became highly emissive by aggregation. These dye@doped polymers were evaluated as temperature sensors, showing an excellent fluorescent response and reversibility after 15 cycles of heating and cooling.
Diphenyl ditelluride assisted synthesis of noble metal-based silver-telluride 2D organometallic nanofibers with enhanced aggregation-induced emission (AIE) after oleylamine treatment
Publication . Djafari, Jamila; Duarte, Frederico; Fernández-Lodeiro, Javier; Fernández-Lodeiro, Adrián; Santos, Hugo; Bladt, Eva; Bals, Sara; Savvidou, Aikaterini Flessa; Balicas, Luis; Rodríguez-González, Benito; Dos Santos, Alcindo Aparecido; Capelo-Martínez, José Luis; Lodeiro, Carlos; LAQV@REQUIMTE; DQ - Departamento de Química; Elsevier
Silver-Telluride 2D organometallic nanofibers (NFs), using diphenyl ditelluride (DPDT) as a precursor, were synthesized. The synthesis was carried out by reacting DPDT with AgNO3 in acetonitrile at room temperature (RT) under an inert atmosphere. The resulting material was fully characterized using various techniques, including UV-VIS-NIR spectroscopy, steady-state and excited-state fluorescence spectroscopy, IR-FTIR-ATR spectroscopy, HR-ESI MS spectrometry, high-resolution transmission electron microscopy (HRTEM), BF-STEM or HAADF-STEM, confocal fluorescence microscopy images and conductivity measurements. Initially, the nanofibers were almost non-emissive. However, a remarkable modification was observed after treating the nanofibers with oleylamine under ultrasound treatment. This methodology induced an aggregation emission effect (AIE) in the solution and in the solid state, resulting in the formation of a highly red emissive fluorescent nanomaterial. This research provides valuable insights for developing new fluorescent materials with potential applications in various optical fields.
Development of fluorochromic polymer doped materials as platforms for temperature sensing using three dansyl derivatives bearing a sulfur bridge
Publication . Duarte, Frederico; Dobrikov, Georgi; Kurutos, Atanas; Capelo-Martinez, José Luis; Santos, Hugo M.; Oliveira, Elisabete; Lodeiro, Carlos; DQ - Departamento de Química; LAQV@REQUIMTE; Elsevier
Three novel bis-dansyl derivatives bearing a sulfur bridge have been synthesized, fully characterized, and their photophysical characterization studied in solution, as well as, in the solid state. All compounds exhibit fluorescence emission with quantum yields up to 60%, which vary significantly depending on the solvent used, and the inherent molecular structure. Moreover, these compounds demonstrate positive solvatofluorochromic behaviour emitting from bluish-green to yellow. Kamlet-Taft studies were performed to better understand the solute–solvent interactions. Due to the intrinsic characteristics of the compounds, efforts were made to understand their potential usefulness for environmental remediation and thus metal ion sensing studies were investigated. Compounds L1 and L2 showed high sensitivity to Cu2+ and Hg2+ ions and were found to modulate their emission extensively, with L2 capable of detecting and quantifying up to 4 µM of Hg2+. Considering the solid-state emission of these compounds, the application towards temperature sensing was put forth. L3 was found to quench its emission in a linear relation with temperature up to 170 °C. Several doped polymer thin films were fabricated, which served as a platform to establish a linear relation with temperature beyond their melting point. Polymethylmetacrylate (PMMA) films emitted up to temperatures of 218 °C, which could be fully restored at room temperature. These results suggest the potential application of these bis-chromophoric compounds as molecular thermometers.
Enhancing water sensing via aggregation-induced emission (AIE) and solvatofluorochromic studies using two new dansyl derivatives containing a disulfide bound
Publication . Duarte, Frederico; Dobrikov, Georgi; Kurutos, Atanas; Santos, Hugo M.; Fernández-Lodeiro, Javier; Capelo-Martinez, José Luis; Oliveira, Elisabete; Lodeiro, Carlos; DQ - Departamento de Química; LAQV@REQUIMTE; Elsevier
Polarity-sensitive dansyl derivatives L1 and L2 were synthesized and their ability to sense pollutant metal ions was investigated. All compounds were found to be highly sensitive towards Cu2+ and Hg2+ metal ions, while L2 being able to detect and quantify Hg2+ concentrations as low as 2.5 μM. Both L1 and L2 exhibit positive solvatofluorochromic behaviour, modulated in the presence of water, which in turn results in fluorescence enhancement via aggregation-induced emission (AIE). Seeking stability and water solubility, luminescent L1-based polystyrene-block-polybutadiene-block-polystyrene (SBS) microparticles (size: 520 ± 76 nm) were successfully prepared while maintaining the fluorescence emission of fluorophore L1 (φ = 22%). This work exemplifies the multiple properties of dansyl-derivatives and their promising applications in biomedicine and environmental fields.
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Fundação para a Ciência e a Tecnologia
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OE
Número da atribuição
2021.05161.BD