Publications by authors named "Raquel R C Vilela"

Development of efficient portable sensors for accurately detecting biomarkers is crucial for early disease diagnosis, yet remains a significant challenge. To address this need, we introduce the enhanced luminescence lateral-flow assay, which leverages highly luminescent upconverting nanoparticles (UCNPs) alongside a portable reader and a smartphone app. The sensor's efficiency and versatility were shown for kidney health monitoring as a proof of concept.

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Self-activated luminescent calcium phosphate (CaP) nanoparticles, including hydroxyapatite (HA) and amorphous calcium phosphate (ACP), are promising for bioimaging and theragnostic applications in nanomedicine, eliminating the need for activator ions or fluorophores. In this study, we developed luminescent and stable citrate-functionalized carbonated ACP nanoparticles for bioimaging purposes. Our findings revealed that both the CO content and the posterior heating step at 400 °C significantly influenced the composition and the structural ordering of the chemically precipitated ACP nanoparticles, impacting the intensity, broadness, and position of the defect-related photoluminescence (PL) emission band.

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Organically modified mesoporous silica nanoparticles (MSNs) containing Ir complexes (Ir1, Ir2 and Ir3) were successfully synthesized. These Ir-entrapped MCM41-COOH nanoparticles have shown relevant photophysical characteristics including high efficiency in the photoproduction and delivery of singlet oxygen (O), which is particularly promising for photodynamic therapy (PDT) applications. In vitro tests have evidenced that complex@MCM41-COOH are able to reduce cell proliferation after 10 min of blue-light irradiation in Hep-G2 liver cancer cells.

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In the search for understanding and improving the luminescence of optical materials based on Ir(III) complexes, three [Ir(CN)(dnbp)] (dnbp = 4,4'-dinonyl-2,2'-bipyridine) emitters were immobilized in MCM-41 mesoporous nanoparticles. By taking advantage of the amphiphilic nature of [Ir(CN)(dnbp)], the complexes were mixed with an appropriate surfactant and the resulting micelles served as templates for the synthesis of mesoporous silica host materials in a one-step sol-gel route. The MCM-encapsulated [Ir(CN)(dnbp)] complexes present intense emissions with prominent rigidochromic spectral changes that are substantially less affected by O as compared to methanolic solutions, with a thousand-fold decrease in quenching rate constants.

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