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M. Algarra
Department of Inorganic Chemistry, Faculty of Science, University of Málaga, 29007 Málaga, Spain

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Journal article
Published: 24 July 2021 in Chemosensors
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Here we report the rational development of a carbon dot (CDs)-based fluorescent pH nanosensor by employing an active surface preservation strategy. More specifically, citric acid, urea and fluorescein were subjected to a one-pot hydrothermal treatment, which preserved fluorescein-like structures on the surface of the CDs. The obtained CDs showed pH-sensitive green emission, which can be used to determine pH variations from 3.7 to 12.1 by fluorescence enhancement. Moreover, the obtained nanoparticles showed excellent selectivity toward pH, fluorescence reversibility in different pH values, photostability, while being compatible with human cell lines (even at high concentrations). Furthermore, their performance as pH sensors was comparable with reference pH determination procedures. Thus, an active surface preservation strategy was successfully employed to develop fluorescence pH nanosensors in a rational manner and without post-synthesis functionalization strategies, which show potential for future use in pH determination.

ACS Style

Ana Afonso; Ana Correia; Diana Duarte; Ana Brandão; Maria de Yuso; José Jiménez-Jiménez; Nuno Vale; Carlos Pereira; Manuel Algarra; Luís Pinto da Silva. An Active Surface Preservation Strategy for the Rational Development of Carbon Dots as pH-Responsive Fluorescent Nanosensors. Chemosensors 2021, 9, 191 .

AMA Style

Ana Afonso, Ana Correia, Diana Duarte, Ana Brandão, Maria de Yuso, José Jiménez-Jiménez, Nuno Vale, Carlos Pereira, Manuel Algarra, Luís Pinto da Silva. An Active Surface Preservation Strategy for the Rational Development of Carbon Dots as pH-Responsive Fluorescent Nanosensors. Chemosensors. 2021; 9 (8):191.

Chicago/Turabian Style

Ana Afonso; Ana Correia; Diana Duarte; Ana Brandão; Maria de Yuso; José Jiménez-Jiménez; Nuno Vale; Carlos Pereira; Manuel Algarra; Luís Pinto da Silva. 2021. "An Active Surface Preservation Strategy for the Rational Development of Carbon Dots as pH-Responsive Fluorescent Nanosensors." Chemosensors 9, no. 8: 191.

Review
Published: 01 July 2021 in Toxics
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Phthalates are a group of chemicals used in a multitude of important industrial products (e.g., medical devices, children’s toys, and food packages), mainly as plasticizers to improve mechanical properties such as flexibility, transparency, durability, and longevity of polyvinyl chloride (PVC). The wide occurrence of phthalates in many consumer products, including foods (e.g., bottled water, soft drinks, wine, milk, and meat) brings that most people are exposed to phthalates every day, which raises some concerns. Adverse health outcomes from phthalates exposure have been associated with endocrine disruption, deformities in the human reproductive system, increased risk of preterm birth, carcinogen exposure, among others. Apprehension related to the health risks and ubiquitous incidence of phthalates in foods inspires the development of reliable analytical approaches that allow their detection and quantification at trace levels. The purpose of the current review is to provide information related to the presence of phthalates in the food chain, highlighting the health risks associated with their exposure. Moreover, an overview of emerging extraction procedures and high-resolution analytical approaches for a comprehensive quantification of phthalates is presented.

ACS Style

Catarina Luís; Manuel Algarra; José Câmara; Rosa Perestrelo. Comprehensive Insight from Phthalates Occurrence: From Health Outcomes to Emerging Analytical Approaches. Toxics 2021, 9, 157 .

AMA Style

Catarina Luís, Manuel Algarra, José Câmara, Rosa Perestrelo. Comprehensive Insight from Phthalates Occurrence: From Health Outcomes to Emerging Analytical Approaches. Toxics. 2021; 9 (7):157.

Chicago/Turabian Style

Catarina Luís; Manuel Algarra; José Câmara; Rosa Perestrelo. 2021. "Comprehensive Insight from Phthalates Occurrence: From Health Outcomes to Emerging Analytical Approaches." Toxics 9, no. 7: 157.

Journal article
Published: 29 June 2021 in Conservar Património
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ISEP Museum was founded in 1999. It stores the memory of industrial school dated from the second half of XIX century. The education, at that time, was very practical and the methodology was based on models and tools. The collections are formed by 3 main typological groups: objects, prints/drawings and photos, a total of about 10 thousand pieces. The complexity of this collection causes multiple challenges concerning to conservation and management subjects. Recently, the main concern focus on the objects, because the lack of technical interventions by specialists. For instance, the Grenet and Leclanché cells are two case studies that show the prominent need of a technical intervention. This article presents a historical contextualization of cells, their composition and the conservation state of their constituent materials. The obtained results will attend to clarify further conservation and restoration approaches.

ACS Style

Guilhermina Cadeco; Patrícia Costa; Bruno B. Campos; Manuel Algarra; M.ª Valle Martínez de Yuso; Patrícia R. Moreira; Paulo Silva; Eduarda Vieira. The scientific collection of ISEP Museum: Grenet and Leclanché cells. Conservar Património 2021, 1 .

AMA Style

Guilhermina Cadeco, Patrícia Costa, Bruno B. Campos, Manuel Algarra, M.ª Valle Martínez de Yuso, Patrícia R. Moreira, Paulo Silva, Eduarda Vieira. The scientific collection of ISEP Museum: Grenet and Leclanché cells. Conservar Património. 2021; ():1.

Chicago/Turabian Style

Guilhermina Cadeco; Patrícia Costa; Bruno B. Campos; Manuel Algarra; M.ª Valle Martínez de Yuso; Patrícia R. Moreira; Paulo Silva; Eduarda Vieira. 2021. "The scientific collection of ISEP Museum: Grenet and Leclanché cells." Conservar Património , no. : 1.

Research article
Published: 28 May 2021 in Inorganic Chemistry Frontiers
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Cu/TiO2 photocatalysts can be considered a promising low-cost alternative to the well-known Pt/TiO2 system for hydrogen production under UV-Vis irradiation.

ACS Style

Laura Diaz; Vicente Rodriguez; Modesto González-Rodríguez; Enrique Rodriguez-Castellon; Manuel Algarra; Pedro Nunez; Elisa Moretti. M/TiO2 (M = Fe, Co, Ni, Cu, Zn) catalysts for photocatalytic hydrogen production under UV and visible light irradiation. Inorganic Chemistry Frontiers 2021, 1 .

AMA Style

Laura Diaz, Vicente Rodriguez, Modesto González-Rodríguez, Enrique Rodriguez-Castellon, Manuel Algarra, Pedro Nunez, Elisa Moretti. M/TiO2 (M = Fe, Co, Ni, Cu, Zn) catalysts for photocatalytic hydrogen production under UV and visible light irradiation. Inorganic Chemistry Frontiers. 2021; ():1.

Chicago/Turabian Style

Laura Diaz; Vicente Rodriguez; Modesto González-Rodríguez; Enrique Rodriguez-Castellon; Manuel Algarra; Pedro Nunez; Elisa Moretti. 2021. "M/TiO2 (M = Fe, Co, Ni, Cu, Zn) catalysts for photocatalytic hydrogen production under UV and visible light irradiation." Inorganic Chemistry Frontiers , no. : 1.

Journal article
Published: 07 May 2021 in Colloids and Surfaces B: Biointerfaces
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Carbon dots are biocompatible and non-toxic nanoparticles with chemical affinity to some heavy metals. Human activities increase soil pollution with copper. Cu is an essential microelement in plants, but excess can induce a harmful effects. In plant response to Cu, the cell wall plays an important role. This study aims to estimate possible amelioration effects of folic acid based CDs on Cu toxicity by studying the intracellular and cell wall compounds in maize (Zea mays L.) roots and leaves after 7 day-treatment in hydroponics. The sub-cellular compartmentalization and bio-macromolecular changes induced by 5 μM Cu applied alone or with CDs (167 and 500 mg/L) were studied using the Synchrotron-based Fourier transformmicro-spectroscopy (SR-FTIR) combined with X-Ray photoelectron spectroscopy (XPS). Cu induced changes in content of cell wall polysaccharides, proteins, and lipids. The XPS detected CDs transport throughout the plants. The Cu/167CDs treatment reduced Cu concentration in the roots, possibly by complexation/trapping between the functional groups on CDs surface and Cu2+. Principal component analysis of FTIR spectra confirmed that Cu/500CDs treatment increased Cu adverse effects in most tissues but alleviated adverse Cu effects on cell wall polysaccharides in the root xylem, and on polysaccharides and proteins in leaf phloem and mesophyll.

ACS Style

Tanja Dučić; Ivana Milenković; Dragosav Mutavdžić; Miroslav Nikolić; M. Valle Martínez de Yuso; Željko Vučinić; Manuel Algarra; Ksenija Radotić. Estimation of carbon dots amelioration of copper toxicity in maize studied by synchrotron radiation-FTIR. Colloids and Surfaces B: Biointerfaces 2021, 204, 111828 .

AMA Style

Tanja Dučić, Ivana Milenković, Dragosav Mutavdžić, Miroslav Nikolić, M. Valle Martínez de Yuso, Željko Vučinić, Manuel Algarra, Ksenija Radotić. Estimation of carbon dots amelioration of copper toxicity in maize studied by synchrotron radiation-FTIR. Colloids and Surfaces B: Biointerfaces. 2021; 204 ():111828.

Chicago/Turabian Style

Tanja Dučić; Ivana Milenković; Dragosav Mutavdžić; Miroslav Nikolić; M. Valle Martínez de Yuso; Željko Vučinić; Manuel Algarra; Ksenija Radotić. 2021. "Estimation of carbon dots amelioration of copper toxicity in maize studied by synchrotron radiation-FTIR." Colloids and Surfaces B: Biointerfaces 204, no. : 111828.

Journal article
Published: 20 April 2021 in Estudios sobre el Mensaje Periodístico
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En este artículo se hace una revisión de las 50 publicaciones en inglés y español con más impacto sobre tecnología y periodismo detectadas través de la herramienta Dimension combinada con Google Académico. Los objetivos son realizar un mapa de las líneas de investigación predominantes en este tema, las publicaciones más relevantes y los autores más citados, así como comprobar si hay en los contenidos de esas investigaciones unas líneas comunes que dibujan tendencias sobre la tecnología y el periodismo, las aportaciones y carencias. La tecnología ha afectado a las audiencias y al periodista, a los valores éticos y económicos de los medios, a la transmisión del saber periodístico; entre otros asuntos. Se echa de menos una mayor reflexión sobre lo que estos cambios pueden suponer para las democracias y la reorientación del poder y el conocimiento.

ACS Style

Montserrat Doval-Avendaño; Manuel Martín Algarra. Periodismo y tecnología, tendencias de investigación y propuestas. Estudios sobre el Mensaje Periodístico 2021, 27, 463 -480.

AMA Style

Montserrat Doval-Avendaño, Manuel Martín Algarra. Periodismo y tecnología, tendencias de investigación y propuestas. Estudios sobre el Mensaje Periodístico. 2021; 27 (2):463-480.

Chicago/Turabian Style

Montserrat Doval-Avendaño; Manuel Martín Algarra. 2021. "Periodismo y tecnología, tendencias de investigación y propuestas." Estudios sobre el Mensaje Periodístico 27, no. 2: 463-480.

Research article
Published: 16 April 2021 in Journal of Medicinal Chemistry
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The control of Parkinson’s disease (PD) is challenged by the motor and non-motor fluctuations as well as dyskinesias associated with levodopa long-term therapy. As such, pharmacological alternatives to reduce the reliance on this drug are needed. Melanostatin (MIF-1), a positive allosteric modulator (PAM) of D2 receptors (D2R), is being explored as a novel pharmacological approach focused on D2R potentiation. In this work, 3-furoic acid (3-Fu) was successfully employed as an l-proline (Pro) surrogate, affording two potent MIF-1 analogues, methyl 3-furoyl-l-leucylglycinate (4a) and 3-furoyl-l-leucylglycinamide (6a). In this series, the C-terminal carboxamide moiety was found crucial to enhancing the potency and toxicological profile, yet it is not considered a requisite for the PAM activity. Conformational analysis excludes 4a from adopting the claimed type II β-turn. The discovery and validation of 6a as a lead compound open a new avenue for the development of a novel class of anti-Parkinson therapeutics targeting the D2R.

ACS Style

Ivo E. Sampaio-Dias; Ana Reis-Mendes; Vera Marisa Costa; Xerardo García-Mera; José Brea; María Isabel Loza; Beatriz L. Pires-Lima; Cristina Alcoholado; Manuel Algarra; José E. Rodríguez-Borges. Discovery of New Potent Positive Allosteric Modulators of Dopamine D2 Receptors: Insights into the Bioisosteric Replacement of Proline to 3-Furoic Acid in the Melanostatin Neuropeptide. Journal of Medicinal Chemistry 2021, 64, 6209 -6220.

AMA Style

Ivo E. Sampaio-Dias, Ana Reis-Mendes, Vera Marisa Costa, Xerardo García-Mera, José Brea, María Isabel Loza, Beatriz L. Pires-Lima, Cristina Alcoholado, Manuel Algarra, José E. Rodríguez-Borges. Discovery of New Potent Positive Allosteric Modulators of Dopamine D2 Receptors: Insights into the Bioisosteric Replacement of Proline to 3-Furoic Acid in the Melanostatin Neuropeptide. Journal of Medicinal Chemistry. 2021; 64 (9):6209-6220.

Chicago/Turabian Style

Ivo E. Sampaio-Dias; Ana Reis-Mendes; Vera Marisa Costa; Xerardo García-Mera; José Brea; María Isabel Loza; Beatriz L. Pires-Lima; Cristina Alcoholado; Manuel Algarra; José E. Rodríguez-Borges. 2021. "Discovery of New Potent Positive Allosteric Modulators of Dopamine D2 Receptors: Insights into the Bioisosteric Replacement of Proline to 3-Furoic Acid in the Melanostatin Neuropeptide." Journal of Medicinal Chemistry 64, no. 9: 6209-6220.

Journal article
Published: 27 February 2021 in Applied Sciences
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Phthalates are multifunctional synthetic chemicals found in a wide array of consumer and industrial products, mainly used to improve the mechanical properties of plastics, giving them flexibility and softness. In the European Union, phthalates are prohibited at levels greater than 0.1% by weight in most food packaging. In the current study, headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was optimized, through the multivariate optimization process, and validated to evaluate the occurrence of four common phthalates, di-iso-butyl phthalate (DIBP), butyl-benzyl phthalate (BBP), di-n-octyl phthalate (DOP), and 2,2,4,4-tetrabromodiphenyl (BDE), in different food packaging. The best extraction efficiency was achieved using the polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber at 80 °C for 30 min. The validated method showed good linearity, precision (RSD < 13%), and recoveries (90.2 to 111%). The limit of detection (LOD) and of quantification (LOQ) ranged from 0.03 to 0.08 µg/L and from 0.10 to 0.24 µg/L, respectively. On average, the phthalates concentration varied largely among the assayed food packaging. DIBP was the most predominant phthalate in terms of occurrence (71.4% of analyzed simples) and concentration (from 3.61 to 10.7 μg/L). BBP was quantified in only one sample and BDE was detected in trace amounts (

ACS Style

Rosa Perestrelo; Catarina Silva; Manuel Algarra; José Câmara. Evaluation of the Occurrence of Phthalates in Plastic Materials Used in Food Packaging. Applied Sciences 2021, 11, 2130 .

AMA Style

Rosa Perestrelo, Catarina Silva, Manuel Algarra, José Câmara. Evaluation of the Occurrence of Phthalates in Plastic Materials Used in Food Packaging. Applied Sciences. 2021; 11 (5):2130.

Chicago/Turabian Style

Rosa Perestrelo; Catarina Silva; Manuel Algarra; José Câmara. 2021. "Evaluation of the Occurrence of Phthalates in Plastic Materials Used in Food Packaging." Applied Sciences 11, no. 5: 2130.

Journal article
Published: 07 February 2021 in Journal of Colloid and Interface Science
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A binary system composed of carbon dots (CDs) and N-doped CDs (N-CDs) embedded in an organic matrix was used for the analysis of cholesterol by MALDI (matrix-assisted laser desorption and ionization time-of-flight) mass spectrometry, as a model for detection of small, biologically relevant molecules. The results showed that both CDs are sensitive to the cholesterol and can be used either alone or in a binary system with 2,5-dihydroxybenzoic acid (DHB) to enhance the detection process. It was found that both COOH and NH2 groups on CDs surface contributed to the enhancement in the cholesterol detection by MALDI mass spectrometry in the presence of inorganic cations. Nevertheless, in the presence of NaCl, N-CDs led to a better reproducibility of results. It was due to the coexistence of positive and negative charge on N-CDs surface that led to a homogeneous analyte/substrate distribution, which is an important detection parameter. The enhancing effect of carbon dots was linked to a negative Gibbs energy of the complex formation between CDs, Na+, cholesterol and DHB, and it was supported by theoretical calculations. Moreover, upon the addition of CDs/N-CDs, such features as a low ionization potential, vertical excitation, dipole moment and oscillator strength positively affected the cholesterol detection by MALDI in the presence of Na+.

ACS Style

Dominika Houdová; Juan Soto; Rita Castro; João Rodrigues; Mª Soledad Pino-González; Marijana Petković; Teresa J Bandosz; Manuel Algarra. Chemically heterogeneous carbon dots enhanced cholesterol detection by MALDI TOF mass spectrometry. Journal of Colloid and Interface Science 2021, 591, 373 -383.

AMA Style

Dominika Houdová, Juan Soto, Rita Castro, João Rodrigues, Mª Soledad Pino-González, Marijana Petković, Teresa J Bandosz, Manuel Algarra. Chemically heterogeneous carbon dots enhanced cholesterol detection by MALDI TOF mass spectrometry. Journal of Colloid and Interface Science. 2021; 591 ():373-383.

Chicago/Turabian Style

Dominika Houdová; Juan Soto; Rita Castro; João Rodrigues; Mª Soledad Pino-González; Marijana Petković; Teresa J Bandosz; Manuel Algarra. 2021. "Chemically heterogeneous carbon dots enhanced cholesterol detection by MALDI TOF mass spectrometry." Journal of Colloid and Interface Science 591, no. : 373-383.

Journal article
Published: 23 November 2020 in Medicinal Chemistry
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Background: Curcumin is a safe, versatile natural product with unlimited number of biological activities and a precursor for various heterocyclic compounds. Objective: The present study was aimed to the development of a curcumin based antimicrobial reagent with high potency against gram-positive and gram-negative bacteria. Methods: Herein we report a simple and convenient one step method for synthesizing a series of 1,4-benzodiazepines via condensation cyclization reaction between curcumin and various 1,2- phenylenediamine in refluxed ethanol. Results: A series of new 1,4-benzodiazepins were synthesized and their structures were supported by FT-IR, 1H NMR, 13C NMR, and mass spectral analysis. Synthesized 1,4-benzodiazepins were evaluated for their in vitro antimicrobial activity against gram positive (S. aureus and S. epidermidis) and gram negative (E. coli and P. aeruginosa) bacteria. They exhibited low to high potency against the tested organisms. In particular, dichlorinated 1,4-benzodiazepine 9 exhibited a remarkable potency against the gram-positive bacteria S. aureus (MIC: 3.125 μg mL-1, MBC: 12 μg mL-1). It showed a higher potency than most of the tested reference drugs. Compound 9 showed the medium activity against E. coli. Genotoxic study revealed that, benzodiazepines 9 attacked the DNA of E. coli strains and damaged it. The potency of compound 9, could be attributed to the multiple chlorine atoms present on the aromatic ring. Conclusion: Some of the synthesized curcumin based benzodiazepines showed excellent potency against gram positive bacteria. These benzodiazepines could be a great candidate as a future antimicrobial agent.

ACS Style

Othman Hamed; Oswa Fares; Shaima Taleeb; Ghaleb Adwan; Haythem Saadeh; Shehdeh Jodeh; Manuel Algarra. New Insights Towards 1,4-Benzodiazepines from Curcumin. Design, Synthesis and Antimicrobial Activities. Medicinal Chemistry 2020, 16, 1112 -1123.

AMA Style

Othman Hamed, Oswa Fares, Shaima Taleeb, Ghaleb Adwan, Haythem Saadeh, Shehdeh Jodeh, Manuel Algarra. New Insights Towards 1,4-Benzodiazepines from Curcumin. Design, Synthesis and Antimicrobial Activities. Medicinal Chemistry. 2020; 16 (8):1112-1123.

Chicago/Turabian Style

Othman Hamed; Oswa Fares; Shaima Taleeb; Ghaleb Adwan; Haythem Saadeh; Shehdeh Jodeh; Manuel Algarra. 2020. "New Insights Towards 1,4-Benzodiazepines from Curcumin. Design, Synthesis and Antimicrobial Activities." Medicinal Chemistry 16, no. 8: 1112-1123.

Journal article
Published: 25 August 2020 in Talanta
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We studied the possibility of detection of [Ru(η5-C5H5)(PPh3)2Cl] (abbreviated by RuCp) complex as a model system for Ru-based metallodrugs in human urine by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) without previous purification or removal of inorganic salts. Inorganic salts might prevent the detection of RuCp by MALDI-TOF MS, most likely through the increased number and intensity of background/organic matrix signals. This problem might be overcome by the acquisition of matrix-free spectra and the addition of nanoparticles, such as carbon dots, to the urine solution. Our results suggest that RuCp is easily detectable by MALDI-TOF MS in all acquisition conditions, with the CHCA matrix being the best for acquisition in phosphate-containing solutions, whereas in urine, DHB and matrix-free approach demonstrated the highest sensitivity, precision, and reproducibility. The sensitivity of matrix-free MALDI detection of RuCp could be increased by the addition of carbon dots to the urine. Based on theoretical calculations for all matrix/analyte combinations, the model for the interaction of RuCp with carbon dots was established, and higher sensitivity explained.

ACS Style

Nádia Nunes; Iva Popović; Elder Abreu; Dina Maciel; João Rodrigues; Juan Soto; Manuel Algarra; Marijana Petkovic. Detection of Ru potential metallodrug in human urine by MALDI-TOF mass spectrometry: Validation and options to enhance the sensitivity. Talanta 2020, 222, 121551 .

AMA Style

Nádia Nunes, Iva Popović, Elder Abreu, Dina Maciel, João Rodrigues, Juan Soto, Manuel Algarra, Marijana Petkovic. Detection of Ru potential metallodrug in human urine by MALDI-TOF mass spectrometry: Validation and options to enhance the sensitivity. Talanta. 2020; 222 ():121551.

Chicago/Turabian Style

Nádia Nunes; Iva Popović; Elder Abreu; Dina Maciel; João Rodrigues; Juan Soto; Manuel Algarra; Marijana Petkovic. 2020. "Detection of Ru potential metallodrug in human urine by MALDI-TOF mass spectrometry: Validation and options to enhance the sensitivity." Talanta 222, no. : 121551.

Research article
Published: 04 August 2020 in ACS Applied Nano Materials
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Herein, we have fabricated nanoparticles of doped carbon dots with nitrogen (N-CDs) with an ecofriendly and easy approach, yielding spherical nanoparticles (mean size: 19 nm). N-CDs were further characterized by HR-TEM microscopy, XPS and fluorescence spectroscopy. In addition, it was developed a fluorometric method for determination of dopamine (DA) in hu-man fluids at nanomolar concentration (rapid and highly sensitive). The quenching effect over the emission of the doped carbon dots at 438 nm, was the basis of the quantification of DA. A linear trend between 0-652 nM was the range of applica-tion with a detection limit at 4 nM, acceptable accuracy (>80%) and precision (RSD<10%), showing a highest selectivity with related analytes. The obtained sensing method was applied for DA determination in human fluids (urine, and serum samples) with acceptable accuracy. In order to understand the interaction of dopamine with the nanoparticles of N-CDs, we have applied density functional theory. The bonding between the -NH3+ moiety of dopamine and the corresponding N-CDs surface ligand consists of the formation of hydrogen bonds. It is demonstrated that the selected geometrical models explain the spectroscopic experiments performed on such nanoparticles.

ACS Style

Marwa Louleb; Latifa Latrous; Ángel Ríos; Mohammed Zougagh; Enrique Rodríguez-Castellón; Manuel Algarra; Juan Soto. Detection of Dopamine in Human Fluids Using N-Doped Carbon Dots. ACS Applied Nano Materials 2020, 3, 1 .

AMA Style

Marwa Louleb, Latifa Latrous, Ángel Ríos, Mohammed Zougagh, Enrique Rodríguez-Castellón, Manuel Algarra, Juan Soto. Detection of Dopamine in Human Fluids Using N-Doped Carbon Dots. ACS Applied Nano Materials. 2020; 3 (8):1.

Chicago/Turabian Style

Marwa Louleb; Latifa Latrous; Ángel Ríos; Mohammed Zougagh; Enrique Rodríguez-Castellón; Manuel Algarra; Juan Soto. 2020. "Detection of Dopamine in Human Fluids Using N-Doped Carbon Dots." ACS Applied Nano Materials 3, no. 8: 1.

Research article
Published: 10 July 2020 in Journal of Agricultural and Food Chemistry
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Phthalates are a class of endocrine disruptors extensively used in plastic production as plasticizers, and as a result, they can be found in foods as a result of their migration ability. The occurrence of phthalates was monitored in 20 Portuguese wines using a simple, reliable, and environmentally friendly analytical method, headspace solid-phase microextraction combined with gas chromatography–mass spectrometry. Satisfactory figures of merit of method, linearity (correlation coefficient of ≥0.992), recovery (80.3–107.6%), precision (relative standard deviation of <13%), and limits of detection (0.03–0.11 μg/L) and quantification (0.09–0.36 μg/L) were achieved. Dibutyl phthalate and di-n-octyl phthalate were found in measurable quantities in table and fortified wines. The obtained results revealed that these wines do not represent any concern for human exposure, because their concentrations were lower than the tolerable daily intakes established by the European Food Safety Authority.

ACS Style

Rosa Perestrelo; Catarina L. Silva; Manuel Algarra; José S. Câmara. Monitoring Phthalates in Table and Fortified Wines by Headspace Solid-Phase Microextraction Combined with Gas Chromatography–Mass Spectrometry Analysis. Journal of Agricultural and Food Chemistry 2020, 68, 8431 -8437.

AMA Style

Rosa Perestrelo, Catarina L. Silva, Manuel Algarra, José S. Câmara. Monitoring Phthalates in Table and Fortified Wines by Headspace Solid-Phase Microextraction Combined with Gas Chromatography–Mass Spectrometry Analysis. Journal of Agricultural and Food Chemistry. 2020; 68 (31):8431-8437.

Chicago/Turabian Style

Rosa Perestrelo; Catarina L. Silva; Manuel Algarra; José S. Câmara. 2020. "Monitoring Phthalates in Table and Fortified Wines by Headspace Solid-Phase Microextraction Combined with Gas Chromatography–Mass Spectrometry Analysis." Journal of Agricultural and Food Chemistry 68, no. 31: 8431-8437.

Journal article
Published: 04 July 2020 in Journal of Colloid and Interface Science
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Optical and electrical modifications of a highly hydrophilic cellulose regenerated (RC) thin film as result of the inclusion in the film structure of cadmium-tellurium covered with mercaptosuccinic acid quantum dot nanoparticles (CdTe-MSA QDs) are analysed. CdTe-MSA QDs nanoparticles inclusion was performed by dip-coating of the RC film in an aqueous nano QDs solution, and two different immersion periods (2 h and 24 h) were considered. Impedance spectroscopy measurements, which can give information of changes in both film surface and bulk phase were performed for CdTe-MSA QDs inclusion confirmation as well as the estimation of electrical changes associated to QDs modification. Optical characterization of the original support and the CdTe-MSA(2 h) and CdTe-MSA(24 h) modified films was carried out by light transmittance and ellipsometry spectroscopy (at three different take-off angles). According to these results, the inclusion of CdTe-MSA QDs practically does not reduce the high transparency of the film support, but it increases the reflexion index and extinction coefficient of both modified films. Moreover, fluorescence and XPS measurements were also performed for more complete information on the effect caused by the presence of CdTe-MSA QDs in the cellulosic film. A comparison of changes in physicochemical properties of the cellulosic/CdTe-MSA QDs films and those modified with other nanoparticle quantum dots is also performed.

ACS Style

Manuel Algarra; Ana Cuevas; M. Valle Martínez de Yuso; Juana Benavente. Insights into the formation of an emissive CdTe-quantum-dots/cellulose hybrid film. Journal of Colloid and Interface Science 2020, 579, 714 -722.

AMA Style

Manuel Algarra, Ana Cuevas, M. Valle Martínez de Yuso, Juana Benavente. Insights into the formation of an emissive CdTe-quantum-dots/cellulose hybrid film. Journal of Colloid and Interface Science. 2020; 579 ():714-722.

Chicago/Turabian Style

Manuel Algarra; Ana Cuevas; M. Valle Martínez de Yuso; Juana Benavente. 2020. "Insights into the formation of an emissive CdTe-quantum-dots/cellulose hybrid film." Journal of Colloid and Interface Science 579, no. : 714-722.

Journal article
Published: 21 June 2020 in Nanomaterials
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Spent coffee grounds (SCGs) are known for containing many organic compounds of interest, including carbohydrates, lipids, phenolic compounds and proteins. Therefore, we investigated them as a potential source to obtain carbon dots (CDs) via a nanotechnology approach. Herein, a comparison was performed between CDs produced by SCGs and classic precursors (e.g., citric acid and urea). The SCG-based CDs were obtained via the one-pot and solvent-free carbonization of solid samples, generating nanosized particles (2.1–3.9 nm). These nanoparticles exhibited a blue fluorescence with moderate quantum yields (2.9–5.8%) and an excitation-dependent emission characteristic of carbon dots. SCG-based CDs showed potential as environmentally relevant fluorescent probes for Fe3+ in water. More importantly, life cycle assessment studies validated the production of CDs from SCG samples as a more environmentally sustainable route, as compared to those using classic reported precursors, when considering either a weight- or a function-based functional unit.

ACS Style

Diana M. A. Crista; Abderrahim El Mragui; Manuel Algarra; Joaquim C. G. Esteves Da Silva; Rafael Luque; Luís Pinto Da Silva. Turning Spent Coffee Grounds into Sustainable Precursors for the Fabrication of Carbon Dots. Nanomaterials 2020, 10, 1209 .

AMA Style

Diana M. A. Crista, Abderrahim El Mragui, Manuel Algarra, Joaquim C. G. Esteves Da Silva, Rafael Luque, Luís Pinto Da Silva. Turning Spent Coffee Grounds into Sustainable Precursors for the Fabrication of Carbon Dots. Nanomaterials. 2020; 10 (6):1209.

Chicago/Turabian Style

Diana M. A. Crista; Abderrahim El Mragui; Manuel Algarra; Joaquim C. G. Esteves Da Silva; Rafael Luque; Luís Pinto Da Silva. 2020. "Turning Spent Coffee Grounds into Sustainable Precursors for the Fabrication of Carbon Dots." Nanomaterials 10, no. 6: 1209.

Article
Published: 14 April 2020 in ChemPhysChem
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This work studies the photochemical and thermal decompositions of azidoacetonitrile (N 3 CH 2 CN) from both the experimental and theoretical points of view. The data of the photochemical experiments are taken from the literature, while the thermal decomposition have been carried out by us. In addition, we have performed ab initio calculations of the multiconfigurational type [complete active space self‐consistent field (CASSCF) and the multistate multireference perturbation theory (MS‐CASPT2)]. It is found that the first step of both type of decompositions is N 2 elimination and formation of closed shell singlet nitrene. Afterwards, the nitrene tends to rapidly rearrange into formimidoyl cyanide (HNCHCN). As both reactions progress, the imine isomerizes into formimidoyl isocyanide (HNCHNC). The photoisomerization of the imine takes places thorough a conical intersection, while the same reaction on the ground electronic state occurs via a conventional transition state. The last step of the global reaction is decomposition of the imines into HCN and CNH. In photochemical conditions, the conjunction of the imines and its dissociation products (HCN and CNH) yields adenine

ACS Style

Manuel Algarra; Juan Soto. Insights into the Thermal and Photochemical Reaction Mechanisms of Azidoacetonitrile. Spectroscopic and MS‐CASPT2 Calculations. ChemPhysChem 2020, 21, 1126 -1133.

AMA Style

Manuel Algarra, Juan Soto. Insights into the Thermal and Photochemical Reaction Mechanisms of Azidoacetonitrile. Spectroscopic and MS‐CASPT2 Calculations. ChemPhysChem. 2020; 21 (11):1126-1133.

Chicago/Turabian Style

Manuel Algarra; Juan Soto. 2020. "Insights into the Thermal and Photochemical Reaction Mechanisms of Azidoacetonitrile. Spectroscopic and MS‐CASPT2 Calculations." ChemPhysChem 21, no. 11: 1126-1133.

Research article
Published: 13 February 2020 in The Journal of Physical Chemistry A
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UV photo decomposition of azidomethyl methylsulfide (AMMS) yields to a transient S-methylthiaziridine which rapidly evolves to S-methyl-N-sulfenylmethanimine at 10K. This species was detected by infrared matrix isolation spectroscopy. The mechanism of the photoreaction of AMMS has been investigated by a combined approach, using low temperature matrix isolation FTIR spectroscopy in conjunction with two theoretical methods, namely complete active space self-consistent field (CASSCF) and multi-configurational second-order perturbation (MS-CASPT2). The key step of the reaction is governed by a S2/S1 conical intersection localized in the neighboring of the singlet nitrene minimum which is formed in the first reaction step of the photolysis, that is, N2 elimination from AMMS. Full assignment of the observed infrared spectra of AMMS has been carried out based on comparison with DFT and second-order perturbation Møller-Plesset (MP2) methods.

ACS Style

Manuel Algarra; Juan Soto; Luís Pinto Da Silva; María Soledad Pino-González; José Enrique Rodríguez-Borges; Joëlle Mascetti; Fabien Borget; Adel Reisi-Vanani; Rafael Luque. Insights into the Photodecomposition of Azidomethyl Methyl Sulfide: A S2/S1 Conical Intersection on Nitrene Potential Energy Surfaces Leading to the Formation of S-Methyl-N-sulfenylmethanimine. The Journal of Physical Chemistry A 2020, 124, 1911 -1921.

AMA Style

Manuel Algarra, Juan Soto, Luís Pinto Da Silva, María Soledad Pino-González, José Enrique Rodríguez-Borges, Joëlle Mascetti, Fabien Borget, Adel Reisi-Vanani, Rafael Luque. Insights into the Photodecomposition of Azidomethyl Methyl Sulfide: A S2/S1 Conical Intersection on Nitrene Potential Energy Surfaces Leading to the Formation of S-Methyl-N-sulfenylmethanimine. The Journal of Physical Chemistry A. 2020; 124 (10):1911-1921.

Chicago/Turabian Style

Manuel Algarra; Juan Soto; Luís Pinto Da Silva; María Soledad Pino-González; José Enrique Rodríguez-Borges; Joëlle Mascetti; Fabien Borget; Adel Reisi-Vanani; Rafael Luque. 2020. "Insights into the Photodecomposition of Azidomethyl Methyl Sulfide: A S2/S1 Conical Intersection on Nitrene Potential Energy Surfaces Leading to the Formation of S-Methyl-N-sulfenylmethanimine." The Journal of Physical Chemistry A 124, no. 10: 1911-1921.

Journal article
Published: 03 February 2020 in Talanta
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Nitrogen and sulphur-doped Carbons Dots (N-CDs and S-CDs) were synthesized by a hydrothermal method and incorporated as surface electrode modifiers to evaluate their properties for electrochemical sensing. The first task was to characterize the synthesized materials, for which different spectroscopies, scanning microscopes, mass spectrometry and elementary analysis were performed. Next, a glassy carbon electrode (GCE) was surface-modified with the doped CDs and applied to check the electrochemical signal of different organic compounds corresponding to different families. Water solubility of the doped carbon dots forced us to incorporate them in a graphite-polystyrene ink to complete the modification of electrodes. This modification needed a first activation to obtain a properly conductive surface. The organic compounds examined were salicylic acid, cysteine and ascorbic acid. The modified GCEs exhibited an enhanced sensitivity, probably caused by the increase of active surface, but in addition, signals of salicylic acid were shifted ca. 200 mV to lower potentials, what is a proof of the increase of the heterogeneous electron transfer rate, and a demonstration of an enhanced catalytic response.

ACS Style

Marta Bonet-San-Emeterio; Manuel Algarra; Marijana Petkovic; Manel del Valle. Modification of electrodes with N-and S-doped carbon dots. Evaluation of the electrochemical response. Talanta 2020, 212, 120806 .

AMA Style

Marta Bonet-San-Emeterio, Manuel Algarra, Marijana Petkovic, Manel del Valle. Modification of electrodes with N-and S-doped carbon dots. Evaluation of the electrochemical response. Talanta. 2020; 212 ():120806.

Chicago/Turabian Style

Marta Bonet-San-Emeterio; Manuel Algarra; Marijana Petkovic; Manel del Valle. 2020. "Modification of electrodes with N-and S-doped carbon dots. Evaluation of the electrochemical response." Talanta 212, no. : 120806.

Journal article
Published: 10 January 2020 in Journal of Cleaner Production
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Carbon dots (CDs) are carbon-based nanoparticles with remarkable luminescent properties, which have made them exciting and suitable alternatives to more traditional fluorophores and even to more recent luminescent nanomaterials (such as metal-based quantum dots). However, despite this high interest on CDs, there has been no focus on their sustainable development and fabrication, and so, there is lacking concrete data on their environmental impacts. A life cycle assessment (LCA) approach was used here to compare and understand the environmental impacts of carbon dots (CDs) obtained via six representative bottom-up synthetic strategies (cradle-to-gate). These routes consist on hydrothermal and microwave-assisted synthesis of CDs derived of citric acid (with the occasional addition of urea), which represent current trends in the synthesis of CDs. Results show that for hydrothermal synthesis the use of electricity is dominant for almost all environmental categories, while citric acid produces most impacts for microwave-assisted synthesis. A performance-based comparison was also made by rescaling results with the fluorescence quantum yield of the CDs. This approach changed the rank order of preference in all categories by a significant margin. While previous analysis indicated microwave-assisted synthesis of citric acid-derived CDs to be the most benign in environmental terms, now the option is the synthesis (either by hydrothermal or microwave-assisted treatment) of urea and citric acid-derived CDs.

ACS Style

Ricardo. Sendão; Maria Del Valle Martínez De Yuso; Manuel Algarra; Joaquim Esteves da Silva; Luís Pinto da Silva. Comparative life cycle assessment of bottom-up synthesis routes for carbon dots derived from citric acid and urea. Journal of Cleaner Production 2020, 254, 120080 .

AMA Style

Ricardo. Sendão, Maria Del Valle Martínez De Yuso, Manuel Algarra, Joaquim Esteves da Silva, Luís Pinto da Silva. Comparative life cycle assessment of bottom-up synthesis routes for carbon dots derived from citric acid and urea. Journal of Cleaner Production. 2020; 254 ():120080.

Chicago/Turabian Style

Ricardo. Sendão; Maria Del Valle Martínez De Yuso; Manuel Algarra; Joaquim Esteves da Silva; Luís Pinto da Silva. 2020. "Comparative life cycle assessment of bottom-up synthesis routes for carbon dots derived from citric acid and urea." Journal of Cleaner Production 254, no. : 120080.

Journal article
Published: 14 November 2019 in Journal of Colloid and Interface Science
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In this work, we utilize a top-down approach to synthesize nitrogen doped graphene quantum dots from a 3D-graphene precursor via an eco-friendly hydrothermal method. The nanoparticles obtained showed a 2-3 nm diameter and well dispersion behavior in aqueous media. The reaction mechanism of insertion of nitrogen from polyvinylpolypyrrolidone onto the 3D-graphene structure, via an esterification reaction, was studied by the density functional theory, in addition, the kinetic and thermodynamic magnitudes of the reaction was analyzed with the help of Eyring's transition state theory and statistical thermodynamics. After analysis by ss-NMR and XPS spectroscopies, the functional groups involved in this process were characterized, and N was found mainly as amide / amine groups. Fluorescence emission, which exhibited a red shift (552 nm) and an emission maximum at 512 nm when excited at 480 nm, demonstrated a low stoke shift (Δλ = 32 nm), explained by the proposed structural model.

ACS Style

Manuel Algarra; Virginia Moreno; Juan Lázaro Martínez; Enrique Rodriguez-Castellon; Juan Soto; Julián Morales; Almudena Benítez. Insights into the formation of N doped 3D-graphene quantum dots. Spectroscopic and computational approach. Journal of Colloid and Interface Science 2019, 561, 678 -686.

AMA Style

Manuel Algarra, Virginia Moreno, Juan Lázaro Martínez, Enrique Rodriguez-Castellon, Juan Soto, Julián Morales, Almudena Benítez. Insights into the formation of N doped 3D-graphene quantum dots. Spectroscopic and computational approach. Journal of Colloid and Interface Science. 2019; 561 ():678-686.

Chicago/Turabian Style

Manuel Algarra; Virginia Moreno; Juan Lázaro Martínez; Enrique Rodriguez-Castellon; Juan Soto; Julián Morales; Almudena Benítez. 2019. "Insights into the formation of N doped 3D-graphene quantum dots. Spectroscopic and computational approach." Journal of Colloid and Interface Science 561, no. : 678-686.