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1.
Nanoscale ; 16(27): 13211, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38952232

ABSTRACT

Correction for 'Photoluminescence modification of europium(III)-doped MAl2O4 (M = Zn, Mg) spinels induced by Ag@SiO2 core-shell nanoparticles' by Rodrigo A. Valenzuela-Fernández et al., Nanoscale, 2024, https://doi.org/10.1039/d4nr01526f.

2.
Nanoscale ; 16(27): 13161-13170, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38913015

ABSTRACT

In recent years, there has been an increasing interest in developing new inorganic compounds with exceptional properties for advanced materials. Specifically, compounds containing europium have attracted much attention due to their luminescent properties. These compounds are used in electronics, biotechnology, medicine, and catalysis. Eu is known for its characteristic red emission, which can be influenced by the environment. This study investigates the surface-enhancement luminescence of europium-doped spinel oxides using modified surface with silver (Ag@SiO2 core-shell) nanoparticles as the enhancers. The europium-doped spinels were synthesized through a sol-gel method, and characterization techniques were used to analyze their structure and morphology. Photoluminescence spectra exhibited characteristic Eu3+ transitions, with the hypersensitive transition being the most prominent. The interaction with an Ag@SiO2 modified-surface led to a significant increase in photoluminescence. The study also analyzed the photoluminescence excitation and lifetimes of the oxides, leading to a 7.3-fold increase in photoluminescence. The improvements observed in the luminescence of these tailor-made materials show their potential interest in next-generation technologies.

3.
Chemistry ; 30(10): e202302940, 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38078547

ABSTRACT

Aggregation-Induced Emission (AIE) luminogens have garnered significant interest due to their distinctive applications in different applications. Among the diverse molecular architectures, those based on triphenylamine and thiophene hold prominence. However, a comprehensive understanding of the deactivation mechanism both in solution and films remains lacking. In this study, we synthesized and characterized spectroscopically two AIE luminogens: 5-(4-(bis(4-methoxyphenyl)amino)phenyl)thiophene-2-carbaldehyde (TTY) and 5'-(4-(bis(4-methoxyphenyl)amino)phenyl)-[2,2'-bithiophene]-5-carbaldehyde (TTO). Photophysical and theoretical analyses were conducted in both solution and PMMA films to understand the deactivation mechanism of TTY and TTO. In diluted solutions, the emission behavior of TTY and TTO is influenced by the solvent, and the deactivation of the excited state can occur via locally excited (LE) or twisted intramolecular charge transfer (TICT) state. In PMMA films, rotational and translational movements are constrained, necessitating emission solely from the LE state. Nevertheless, in the PMMA film, excimers-like structures form, resulting in the emergence of a longer wavelength band and a reduction in emission intensity. The zenith of emission intensity occurs when molecules are dispersed at higher concentrations within PMMA, effectively diminishing the likelihood of excimer-like formations. Luminescent Solar Concentrators (LSC) were fabricated to validate these findings, and the optical efficiency was studied at varying concentrations of luminogen and PMMA.

4.
Discov Nano ; 18(1): 129, 2023 Oct 17.
Article in English | MEDLINE | ID: mdl-37847425

ABSTRACT

Carbon dots (CDs) have been quickly extended for nanomedicine uses because of their multiple applications, such as bioimaging, sensors, and drug delivery. However, the interest in increasing their photoluminescence properties is not always accompanied by cytocompatibility. Thus, a knowledge gap exists regarding their interactions with biological systems linked to the selected formulations and synthesis methods. In this work, we have developed carbon dots (CDs) based on poly (ethylene imine) (PEI) and chitosan (CS) by using microwave irradiation, hydrothermal synthesis, and a combination of both, and further characterized them by physicochemical and biological means. Our results indicate that synthesized CDs have sizes between 1 and 5 nm, a high presence of amine groups on the surface, and increased positive ζ potential values. Further, it is established that the choice and use of different synthesis procedures can contribute to a different answer to the CDs regarding their optical and biological properties. In this regard, PEI-only CDs showed the longest photoluminescent emission lifetime, non-hemolytic activity, and high toxicity against fibroblast. On the other hand, CS-only CDs have higher PL emission, non-cytotoxicity associated with fibroblast, and high hemolytic activity. Interestingly, their combination using the proposed methodologies allow a synergic effect in their CDs properties. Therefore, this work contributes to developing and characterizing CD formulations based on PEI and CS and better understanding the CD's properties and biological interaction.

5.
Bioresour Technol ; 260: 95-104, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29625293

ABSTRACT

This study shows the implementation of the Anaerobic Digestion Model (ADM1) in an anaerobic plug-flow reactor (PFR) with two approaches based on the use of consecutive continuous stirred tank reactors (CSTR) connected in serie for considering non-ideal mixing. The two-region (TR) model splits each CSTR into two regions, while the particulate retention (PR) model adds a retention parameter. The models were calibrated and validated based on experimental data from a bench-scale reactor treating cow manure. The PFR conventional model slightly outperformed the non-ideal mixing approaches. However, the PR model showed an increase in biomass retention time treating high solid content substrate. Biogas production was not sensitive to variations of the mixing parameters. The liquid fraction content was better represented by the PR model than the PFR and TR models. The study shows how reactor modelling is useful for monitoring and supervising biogas plants.


Subject(s)
Bioreactors , Manure , Anaerobiosis , Animals , Biofuels , Biomass , Female
6.
RSC Adv ; 8(55): 31261-31266, 2018 Sep 05.
Article in English | MEDLINE | ID: mdl-35548216

ABSTRACT

A new probe (E)-7-(diethylamino)-3-(3-(thiophen-2-yl)acryloyl)-2H-chromen-2-one (ChC16) was synthesized and studied as a turn-on fluorescent probe, based on a Michael addition mechanism for sensing SO2 derivatives, which is favored in the presence of cationic micellar media such as cetylpyridinium bromide (CPB). The probe showed high selectivity and sensitivity toward bisulfite over other anions and biothiols, including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), with a detection limit of 240 nM. Moreover, the probe showed great potential for its practical application in the detection of bisulfite in real samples, such as dry white wine, and in bioimaging.

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