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Prof. Carlos Pereira
CIQUP - Research Center in Chemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal

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0 Cytotoxicity
0 Energy Storage
0 Environmental Security
0 Ionic Liquids
0 Deep eutectic solvents

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Ionic Liquids
electrodeposition
Deep eutectic solvents
Energy Storage
ecotoxicity
Cytotoxicity

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Journal article
Published: 13 August 2021 in Journal of Materials Research and Technology
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Carbon nanotubes (CNTs) are receiving special attention due to their remarkable thermal, electrical, and mechanical properties. The present work reports an innovative synthesis procedure to decorate MWCNTs with silver nanoparticles (Ag-NPs) via pulsed reverse deposition technique using a deep eutectic solvent (DES) based on choline chloride and glycerol as an electrolyte at room temperature, not requiring any previous surface modification of MWCNTs. MWCNTs decorated with Ag-NPs disclose a significant enhancement of their electrochemical performance as demonstrated by the increase of electrode stability and specific capacitance. Electrochemical characterization of the composite material was performed using cyclic voltammetry and charge/discharge curves, achieving a specific capacitance up to 28.50 F. g−1, against 4.70 F. g−1 for the commercial MWCNTs in a three-electrode system. Retention of the specific capacitance up to 99% for the Ag-MWCNTs composites compared with a value of 78% for electrodes modified with commercial MWCNTs. The Ag-MWCNTs composites were characterized through SEM/EDX analysis, ultrahigh-resolution STEM, in which the Z – Contrast image was collected, and Raman analysis to prove the successful attachment of the Ag-NPs to the MWCNTs surface. AFM was performed to evaluate the conductivity of the composites.

ACS Style

Ana T.S.C. Brandão; Sabrina Rosoiu; Renata Costa; Oana Andreea Lazar; A. Fernando Silva; Liana Anicai; Carlos M. Pereira; Marius Enachescu. Characterization and electrochemical studies of MWCNTs decorated with Ag nanoparticles through pulse reversed current electrodeposition using a deep eutectic solvent for energy storage applications. Journal of Materials Research and Technology 2021, 15, 342 -359.

AMA Style

Ana T.S.C. Brandão, Sabrina Rosoiu, Renata Costa, Oana Andreea Lazar, A. Fernando Silva, Liana Anicai, Carlos M. Pereira, Marius Enachescu. Characterization and electrochemical studies of MWCNTs decorated with Ag nanoparticles through pulse reversed current electrodeposition using a deep eutectic solvent for energy storage applications. Journal of Materials Research and Technology. 2021; 15 ():342-359.

Chicago/Turabian Style

Ana T.S.C. Brandão; Sabrina Rosoiu; Renata Costa; Oana Andreea Lazar; A. Fernando Silva; Liana Anicai; Carlos M. Pereira; Marius Enachescu. 2021. "Characterization and electrochemical studies of MWCNTs decorated with Ag nanoparticles through pulse reversed current electrodeposition using a deep eutectic solvent for energy storage applications." Journal of Materials Research and Technology 15, no. : 342-359.

Journal article
Published: 30 July 2021 in Sensing and Bio-Sensing Research
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This work reports the development of a simple and rapid electrochemical immunosensor for the determination of breast cancer biomarker Cancer Antigen 15–3 (CA15–3). Disposable and cost-effective chips, consisting of gold screen-printed electrodes (AuSPEs), were used to develop the portable electrochemical devices for monitoring the biomarker in point-of-care (PoC), under clinical context. The biosensor preparation consisted of two simple steps. First, a self-assembled monolayer (SAM) of mercaptosuccinic acid (MSA) was formed at the AuSPE surface. Then, the CA15–3 antibody was covalently bound to the carboxylic groups standing at the electrode surface using EDC/NHS chemistry. The performance of the developed immunosensor was evaluated by assessing the sensor sensitivity, linear response interval, selectivity and detection limit (LOD). The developed immunosensor provided a wide linear concentration range (from 1.0 to 1000 U mL−1) and low detection levels were achieved (LOD of 0.95 U mL−1), enabling the sensitive detection of the cancer biomarker at clinically relevant levels, using square wave voltammetry (SWV) as electroanalytical technique. Moreover, selectivity studies performed against other cancer biomarkers (CA 125 and CA 19–9) revealed that the antibody has high selectivity for CA15-3 antigen. The immunosensor was applied to the quantification of CA15-3 in artificial serum samples with satisfactory results.

ACS Style

Tânia S.C.R. Rebelo; José A. Ribeiro; M. Goreti F. Sales; Carlos M. Pereira. Electrochemical immunosensor for detection of CA 15-3 biomarker in point-of-care. Sensing and Bio-Sensing Research 2021, 33, 100445 .

AMA Style

Tânia S.C.R. Rebelo, José A. Ribeiro, M. Goreti F. Sales, Carlos M. Pereira. Electrochemical immunosensor for detection of CA 15-3 biomarker in point-of-care. Sensing and Bio-Sensing Research. 2021; 33 ():100445.

Chicago/Turabian Style

Tânia S.C.R. Rebelo; José A. Ribeiro; M. Goreti F. Sales; Carlos M. Pereira. 2021. "Electrochemical immunosensor for detection of CA 15-3 biomarker in point-of-care." Sensing and Bio-Sensing Research 33, no. : 100445.

Journal article
Published: 26 July 2021 in Electrochem
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The design and synthesis of artificial receptors based on molecular imprinting (MI) technology for the development of a new MIP-based biosensor for detection of the stress biomarker α-amylase in human saliva in point-of-care (PoC) applications is described in this work. The portable electrochemical devices for monitoring α-amylase consists of cost-effective and disposable gold screen-printed electrodes (AuSPEs). To build the electrochemical device, the template biomolecule was firstly immobilized directly over the working area of the gold chip previously activated with a self-assembled monolayer (SAM) of cysteamine (CA). Then, pyrrole (Py) monomer was selected as building block of a polymeric network prepared by CV electropolymerization. After the electropolymerization process, the enzyme was removed from the polymer film in order to build the specific recognition sites for the target enzyme. The MIP biosensor showed a very wide linear concentration range (between 3.0 × 10−4 to 0.60 mg mL−1 in buffer solution and between 3.0 × 10−4 to 3.0 × 10−2 mg mL−1 in human saliva) and low detection levels were achieved (LOD < 3.0 × 10−4 mg mL−1) using square wave voltammetry (SWV) as the electroanalytical technique.

ACS Style

Tânia Rebelo; Inês Miranda; Ana Brandão; Laura Sousa; José Ribeiro; António Silva; Carlos Pereira. A Disposable Saliva Electrochemical MIP-Based Biosensor for Detection of the Stress Biomarker α-Amylase in Point-of-Care Applications. Electrochem 2021, 2, 427 -438.

AMA Style

Tânia Rebelo, Inês Miranda, Ana Brandão, Laura Sousa, José Ribeiro, António Silva, Carlos Pereira. A Disposable Saliva Electrochemical MIP-Based Biosensor for Detection of the Stress Biomarker α-Amylase in Point-of-Care Applications. Electrochem. 2021; 2 (3):427-438.

Chicago/Turabian Style

Tânia Rebelo; Inês Miranda; Ana Brandão; Laura Sousa; José Ribeiro; António Silva; Carlos Pereira. 2021. "A Disposable Saliva Electrochemical MIP-Based Biosensor for Detection of the Stress Biomarker α-Amylase in Point-of-Care Applications." Electrochem 2, no. 3: 427-438.

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.

Research article
Published: 26 May 2021 in Analytical Chemistry
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In this work, we describe an innovative methodology based on combined surface plasmon resonance (SPR) and electrochemical responses (eSPR) in the same immunoassay for screening CA 15–3 cancer biomarker with high sensitivity (and selectivity), in a very simple, label-free, accurate, and fully automated manner. Detection was achieved by performing two simple steps. In the first step, direct SPR was used to monitor CA 15–3 interaction with surface immobilized antibody. Two linear response ranges were obtained and the detection limit achieved is poor (LOD of 21 U mL–1). However, in the second detection step, electrochemical measurements at the SPR gold surface were performed to measure the decrease of redox probe peak current upon antigen–antibody interaction, providing a suitable amplification strategy to lower detection levels of CA 15–3 (LOD of 0.0998 U mL–1), without the need of additional complex and/or expensive amplification steps to enhance the sensitivity. Moreover, selectivity studies were performed against other common cancer biomarkers and the results showed that the eSPR immunosensor is selective for the CA 15–3 protein. Finally, the clinical applicability of the developed eSPR biosensing methodology was successfully applied to detect CA 15–3 in human serum samples at clinically relevant levels due to the high sensitivity of electrochemical readout. The same concept may be further extended to other proteins of interest.

ACS Style

José A. Ribeiro; Maria Goreti F. Sales; Carlos M. Pereira. Electrochemistry-Assisted Surface Plasmon Resonance Biosensor for Detection of CA 15–3. Analytical Chemistry 2021, 93, 7815 -7824.

AMA Style

José A. Ribeiro, Maria Goreti F. Sales, Carlos M. Pereira. Electrochemistry-Assisted Surface Plasmon Resonance Biosensor for Detection of CA 15–3. Analytical Chemistry. 2021; 93 (22):7815-7824.

Chicago/Turabian Style

José A. Ribeiro; Maria Goreti F. Sales; Carlos M. Pereira. 2021. "Electrochemistry-Assisted Surface Plasmon Resonance Biosensor for Detection of CA 15–3." Analytical Chemistry 93, no. 22: 7815-7824.

Journal article
Published: 30 December 2020 in Nanomaterials
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The aim of the present study was to investigate the eco-cytotoxicity of several forms of nanomaterials (NM), such as nano-CuO, nano-TiO2, nano-SiO2 and nano-ZnO, on different aquatic species (Raphidocelis subcapitata, Daphnia magna and Lemna minor) following standard protocols and on human cell lines (Caco-2, SV-80, HepG2 and HaCaT). Predicted no-effect concentrations (PNEC) or hazard concentrations for 5% of the species (HC5) were also estimated based on the compilation of data available in the literature. Most of the NM agglomerated strongly in the selected culture media. For the ecotoxicity assays, nano-CuO and nano-ZnO even in particle agglomeration state were the most toxic NM to the freshwater organisms compared to nano-TiO2 and nano-SiO2. Nano-ZnO was the most toxic NM to R. subcapitata and D. magna, while nano-CuO was found to be very toxic to L. minor. Nano-CuO was very toxic to Caco-2 and HepG2 cells, particularly at the highest tested concentrations, while the other NM showed no toxicity to the different cell lines. The HC5 and PNEC values are still highly protective, due to data limitations. However, the present study provides consistent evidence of the potential risks of both nano-CuO and nano-ZnO against aquatic organisms and also their effects on public health.

ACS Style

Tatiana Andreani; Verónica Nogueira; Ana Gavina; Saul Fernandes; José Luís Rodrigues; Vera V. Pinto; Maria José Ferreira; Amélia M. Silva; Carlos M. Pereira; Ruth Pereira. Ecotoxicity to Freshwater Organisms and Cytotoxicity of Nanomaterials: Are We Generating Sufficient Data for Their Risk Assessment? Nanomaterials 2020, 11, 66 .

AMA Style

Tatiana Andreani, Verónica Nogueira, Ana Gavina, Saul Fernandes, José Luís Rodrigues, Vera V. Pinto, Maria José Ferreira, Amélia M. Silva, Carlos M. Pereira, Ruth Pereira. Ecotoxicity to Freshwater Organisms and Cytotoxicity of Nanomaterials: Are We Generating Sufficient Data for Their Risk Assessment? Nanomaterials. 2020; 11 (1):66.

Chicago/Turabian Style

Tatiana Andreani; Verónica Nogueira; Ana Gavina; Saul Fernandes; José Luís Rodrigues; Vera V. Pinto; Maria José Ferreira; Amélia M. Silva; Carlos M. Pereira; Ruth Pereira. 2020. "Ecotoxicity to Freshwater Organisms and Cytotoxicity of Nanomaterials: Are We Generating Sufficient Data for Their Risk Assessment?" Nanomaterials 11, no. 1: 66.

Journal article
Published: 27 November 2020 in U.Porto Journal of Engineering
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The study of sensing materials to the detection of carbon dioxide (CO2) was achieved using p-nitrophenol (pNPh) as a colorimetric indicator. The sensing material was polymerized (NPLn), functionalized with 3-triethoxysilyl propyl isocyanate (IPTES) which sensitivity was tested in the form of a membrane as is and encapsulated in hollow silica nanoparticles. The sensing membranes were tested in a closed gas system comprising very precise flow controllers to deliver different concentrations of CO2 (vs. N2). The combination of the sensing membranes with multimode optical fibers and a dual-wavelength diode (LED) allows the measurement of the CO2 through the analysis of the induced absorbance changes with a self-referenced ratiometric scheme. The analysis of the sensing materials have shown significant changes in their chemical and physical properties and the results attest these materials with a strong potential for assessing CO2 dynamics in environmental, medical, and industrial applications.

ACS Style

João Mendes; Luís Coelho; Carlos Manuel De Melo Pereira; Pedro Jorge. Colorimetry-based System for Gaseous Carbon Dioxide Detection. U.Porto Journal of Engineering 2020, 6, 59 -69.

AMA Style

João Mendes, Luís Coelho, Carlos Manuel De Melo Pereira, Pedro Jorge. Colorimetry-based System for Gaseous Carbon Dioxide Detection. U.Porto Journal of Engineering. 2020; 6 (2):59-69.

Chicago/Turabian Style

João Mendes; Luís Coelho; Carlos Manuel De Melo Pereira; Pedro Jorge. 2020. "Colorimetry-based System for Gaseous Carbon Dioxide Detection." U.Porto Journal of Engineering 6, no. 2: 59-69.

Journal article
Published: 27 November 2020 in U.Porto Journal of Engineering
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Metal and alloys electrodeposition from aqueous electrolytes is restricted due to the narrow electrochemical window and hydrogen evolution. To overcome these disadvantages, over the past years, ionic liquids (ILs) and deep eutectic solvents (DES) based on choline chloride have been successfully applied for the electrodeposition of different metals.Tin (Sn) layers applied to automotive or decorative plating are thought of as ecological alternatives to exchange lead and nickel/chromium coatings. Over the past few years, the attention drawn by metallic alloys and composites, namely Sn alloys (nickel, indium, copper, zinc…) and Sn-carbon materials composites, has increased due to the possibility of applying these materials as anodes for lithium-ion batteries.This review will highlight the leading research regarding the electrodeposition of Sn and several alloys and carbon composites, emphasizing the morphological changes of the alloy combinations using DESs as electrolytes.

ACS Style

Ana Teresa Silva Cardoso Brandão; Renata Costa; António Fernando Silva; Carlos Manuel De Melo Pereira. Nanostructured Tin-based Alloys Composites using Deep Eutectic Solvents as Electrolytes. U.Porto Journal of Engineering 2020, 6, 70 -85.

AMA Style

Ana Teresa Silva Cardoso Brandão, Renata Costa, António Fernando Silva, Carlos Manuel De Melo Pereira. Nanostructured Tin-based Alloys Composites using Deep Eutectic Solvents as Electrolytes. U.Porto Journal of Engineering. 2020; 6 (2):70-85.

Chicago/Turabian Style

Ana Teresa Silva Cardoso Brandão; Renata Costa; António Fernando Silva; Carlos Manuel De Melo Pereira. 2020. "Nanostructured Tin-based Alloys Composites using Deep Eutectic Solvents as Electrolytes." U.Porto Journal of Engineering 6, no. 2: 70-85.

Full paper
Published: 04 May 2020 in ChemistrySelect
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In this work, three universally used redox probes in amperometric biosensing devices, [Fe(CN)6]3−/[Fe(CN)6]4−, Ru[(NH3)6]3+, and ferrocenedimethanol (FDM), were selected to evaluate the stability of electrochemical signals provide by the reporting systems. Studies were carried out at disposable gold screen‐printed electrode (AuSPE) biosensing platforms, commonly used for screening chemical and biological relevant biomolecules. Firstly, electrochemical combined‐surface plasmon resonance (eSPR) studies were performed to evaluated adsorption reversibility and/or formation of redox probe complexes at the bare gold surface when routinely used electrochemical techniques, namely cyclic voltammetry (CV) and square‐wave voltammetry (SWV), are recorded. Then, the results obtained were compared with those obtained at the AuSPE under the same electrochemical conditions. Based on our findings, best experimental conditions, including the type of electrochemical technique used, are speculated for each reporting system in order to improve the analytical signal stability. Finally, a methodology based on SWV technique was applied to modified electrodes to provide a simple and easy tool to ensure diffusion controlled permeability of probes thorough the films to electrode surface.

ACS Style

José A. Ribeiro; Elisa Silva; Patrícia S. Moreira; Carlos Pereira. Electrochemical Characterization of Redox Probes at Gold Screen‐Printed Electrodes: Efforts towards Signal Stability. ChemistrySelect 2020, 5, 5041 -5048.

AMA Style

José A. Ribeiro, Elisa Silva, Patrícia S. Moreira, Carlos Pereira. Electrochemical Characterization of Redox Probes at Gold Screen‐Printed Electrodes: Efforts towards Signal Stability. ChemistrySelect. 2020; 5 (17):5041-5048.

Chicago/Turabian Style

José A. Ribeiro; Elisa Silva; Patrícia S. Moreira; Carlos Pereira. 2020. "Electrochemical Characterization of Redox Probes at Gold Screen‐Printed Electrodes: Efforts towards Signal Stability." ChemistrySelect 5, no. 17: 5041-5048.

Journal article
Published: 23 April 2020 in Sensors and Actuators B: Chemical
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In this work, we combined electrochemical techniques with SPR (eSPR) for the label-free detection of cancer biomarker miRNA-145. Detection was performed in a simple two-step assay. In the first step, the gold sensor surface, previously functionalized with a self-assembled monolayer (SAM) of thiolated RNA probes is incubated with the sample containing the target RNA biomarker. In this step, hybridization of RNA fragments with complementary immobilized probes was monitored in real-time by SPR. In the second step, eSPR measurements were performed to improve the sensitivity of the hybridization assay. Potential-induced deposition of a redox probe at the sensor surface resulted in enhanced SPR response promoted by the electrochemical process, thereby allowing the detection of miRNA-145 at femtomolar level (LOD = 0.56 fM), without sample derivatization or post-hybridization treatment for signal amplification. Good linearity was achieved (R2 = 0.984) over the concentration range from 1.0 fM and 10 nM. Furthermore, the developed eSPR biosensor showed high selectivity towards single-base and two-base mismatch sequences and detection of target miRNA-145 in synthetic human serum was successful achieved.

ACS Style

José A. Ribeiro; M. Goreti F. Sales; Carlos M. Pereira. Electrochemistry-assisted surface plasmon resonance detection of miRNA-145 at femtomolar level. Sensors and Actuators B: Chemical 2020, 316, 128129 .

AMA Style

José A. Ribeiro, M. Goreti F. Sales, Carlos M. Pereira. Electrochemistry-assisted surface plasmon resonance detection of miRNA-145 at femtomolar level. Sensors and Actuators B: Chemical. 2020; 316 ():128129.

Chicago/Turabian Style

José A. Ribeiro; M. Goreti F. Sales; Carlos M. Pereira. 2020. "Electrochemistry-assisted surface plasmon resonance detection of miRNA-145 at femtomolar level." Sensors and Actuators B: Chemical 316, no. : 128129.

Research article
Published: 29 March 2020 in Environmental Science and Pollution Research
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This work reports the role of different dispersants, namely, polyethylene glycol (PEG 200 2%), ethylene glycol 5%, ethanol 2%, dimethyl sulfoxide (DMSO 5%), and polyvinyl alcohol (PVA 5%) in the toxicity profile of several commercial nanomaterials (NM), such as hydrophilic and hydrophobic TiO2, hydrophilic SiO2, SiO2 in aqueous suspension (aq), and ZnO towards the bioluminescent bacterium Aliivibrio fischeri. The majority of NM showed tendency to form agglomerates in the different dispersants. Although some particle agglomeration could be detected, DMSO at 5% was the best dispersant for hydrophobic TiO2 NM while PVA at 5% was the most effective dispersant for the other types of NM. Average size was not the most relevant aspect accounting for their toxicity. A remarkable reduction in average size was followed by a decrease in NM toxicity, as demonstrated for SiO2 aq. in PVA 5%. Contrarily, despite of high particle agglomeration, ZnO NM showed a higher toxicity to bacteria when compared with other tested NM. Independently of the average particle size or surface charge, the dispersant either enhanced the toxicity to bacteria or acted as physical barrier decreasing the NM harmful effect to A. fischeri.

ACS Style

Tatiana Andreani; Paula Vale Fernandes; Verónica Nogueira; Vera V. Pinto; Maria José Ferreira; Maria Graca Rasteiro; Ruth Pereira; Carlos Pereira. The critical role of the dispersant agents in the preparation and ecotoxicity of nanomaterial suspensions. Environmental Science and Pollution Research 2020, 27, 19845 -19857.

AMA Style

Tatiana Andreani, Paula Vale Fernandes, Verónica Nogueira, Vera V. Pinto, Maria José Ferreira, Maria Graca Rasteiro, Ruth Pereira, Carlos Pereira. The critical role of the dispersant agents in the preparation and ecotoxicity of nanomaterial suspensions. Environmental Science and Pollution Research. 2020; 27 (16):19845-19857.

Chicago/Turabian Style

Tatiana Andreani; Paula Vale Fernandes; Verónica Nogueira; Vera V. Pinto; Maria José Ferreira; Maria Graca Rasteiro; Ruth Pereira; Carlos Pereira. 2020. "The critical role of the dispersant agents in the preparation and ecotoxicity of nanomaterial suspensions." Environmental Science and Pollution Research 27, no. 16: 19845-19857.

Journal article
Published: 11 March 2020 in Materials
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The impact of fullerene side chain functionalization with thiophene and carbazole groups on the device properties of bulk-heterojunction polymer:fullerene solar cells is discussed through a systematic investigation of material blends consisting of the conjugated polymer poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3‴-di(2-octyldodecyl)-2,2′;5′,2″;5″,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD) as donor and C60 or C70 fulleropyrrolidines as acceptors. The photovoltaic performance clearly depended on the molecular structure of the fulleropyrrolidine substituents although no direct correlation with the surface morphology of the photoactive layer, as determined by atomic force microscopy, could be established. Although some fulleropyrrolidines possess favorable lowest unoccupied molecular orbital levels, when compared to the standard PC71BM, they originated OPV cells with inferior efficiencies than PC71BM-based reference cells. Fulleropyrrolidines based on C60 produced, in general, better devices than those based on C70, and we attribute this observation to the detrimental effect of the structural and energetic disorder that is present in the regioisomer mixtures of C70-based fullerenes, but absent in the C60-based fullerenes. These results provide new additional knowledge on the effect of the fullerene functionalization on the efficiency of organic solar cells.

ACS Style

Hugo Gaspar; Flávio Figueira; Karol Strutyński; Manuel Melle-Franco; Dzmitry Ivanou; João P. C. Tomé; Carlos M. Pereira; Luiz Pereira; Adélio Mendes; Júlio C. Viana; Gabriel Bernardo. Thiophene- and Carbazole-Substituted N-Methyl-Fulleropyrrolidine Acceptors in PffBT4T-2OD Based Solar Cells. Materials 2020, 13, 1267 .

AMA Style

Hugo Gaspar, Flávio Figueira, Karol Strutyński, Manuel Melle-Franco, Dzmitry Ivanou, João P. C. Tomé, Carlos M. Pereira, Luiz Pereira, Adélio Mendes, Júlio C. Viana, Gabriel Bernardo. Thiophene- and Carbazole-Substituted N-Methyl-Fulleropyrrolidine Acceptors in PffBT4T-2OD Based Solar Cells. Materials. 2020; 13 (6):1267.

Chicago/Turabian Style

Hugo Gaspar; Flávio Figueira; Karol Strutyński; Manuel Melle-Franco; Dzmitry Ivanou; João P. C. Tomé; Carlos M. Pereira; Luiz Pereira; Adélio Mendes; Júlio C. Viana; Gabriel Bernardo. 2020. "Thiophene- and Carbazole-Substituted N-Methyl-Fulleropyrrolidine Acceptors in PffBT4T-2OD Based Solar Cells." Materials 13, no. 6: 1267.

Original paper
Published: 13 February 2020 in Journal of Solid State Electrochemistry
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The synthesis of noble metal nanoparticles (i.e., silver and gold) for electrochemical applications has been widely studied using mainly wet synthesis chemical methods or electrochemical deposition methods. In this work, we propose a single-step flash photochemical method for synthesizing noble metal nanoparticles (i.e., silver, gold, and Au:Ag) in solution for electrochemical applications. The method is based on the intense pulsed radiation emitted from a xenon flashlamp, which induce the reduction of metal cations in solution to form metallic nanoparticles. The present method is based on the selective light absorption of the metal precursor salts combined with the decomposition of polyvinylpyrrolidone added to the solution. This approach can be termed as flash light synthesis.

ACS Style

Victor Costa Bassetto; Wanderson Oliveira Silva; Carlos Pereira; Hubert H. Girault. Flash light synthesis of noble metal nanoparticles for electrochemical applications: silver, gold, and their alloys. Journal of Solid State Electrochemistry 2020, 24, 1781 -1788.

AMA Style

Victor Costa Bassetto, Wanderson Oliveira Silva, Carlos Pereira, Hubert H. Girault. Flash light synthesis of noble metal nanoparticles for electrochemical applications: silver, gold, and their alloys. Journal of Solid State Electrochemistry. 2020; 24 (8):1781-1788.

Chicago/Turabian Style

Victor Costa Bassetto; Wanderson Oliveira Silva; Carlos Pereira; Hubert H. Girault. 2020. "Flash light synthesis of noble metal nanoparticles for electrochemical applications: silver, gold, and their alloys." Journal of Solid State Electrochemistry 24, no. 8: 1781-1788.

Journal article
Published: 16 January 2020 in Journal of Electroanalytical Chemistry
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Ion transfer electrochemistry is a powerful tool for the study of ionic species in solution. In this paper, square wave voltammetry and chronoamperometry are applied for the quantification and characterization of denatonium ion (N-benzyl-2-(2,6-dimethylphenylamino)-N,N-diethyl-2-oxoethanaminium) in water, an important additive present in commercial products. The method presented is based on the monitoring of the transfer of the cation across a microporous membrane separating an aqueous solution and an organic solution of 1,2-dichloroethane. Calibration curves are built with both techniques and the resulting detection limits and linear ranges of response are discussed. Furthermore, the different performance characteristics of the two techniques are exploited to extract the values of the aqueous diffusion coefficient of the ion denatonium and its standard transfer potential from water to 1,2-dichloroethane. The last parameter is of great importance for the evaluation of the ion lipophilicity, that plays a role in its distribution in living organisms and its impact on biological media.

ACS Style

J.M. Olmos; C.M. Pereira. Electrochemical sensing and characterization of denatonium ion by ion transfer at polarized liquid/liquid interfaces. Journal of Electroanalytical Chemistry 2020, 859, 113860 .

AMA Style

J.M. Olmos, C.M. Pereira. Electrochemical sensing and characterization of denatonium ion by ion transfer at polarized liquid/liquid interfaces. Journal of Electroanalytical Chemistry. 2020; 859 ():113860.

Chicago/Turabian Style

J.M. Olmos; C.M. Pereira. 2020. "Electrochemical sensing and characterization of denatonium ion by ion transfer at polarized liquid/liquid interfaces." Journal of Electroanalytical Chemistry 859, no. : 113860.

Article
Published: 17 December 2019 in Journal of Polymer Science
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A study on the Pb(II) imprinting performed within mesoporous sulphated biopolymer/siloxane composites, prepared in media containing deep eutectic solvent (DES), is described. In general, the process of imprinting resulted in greatly increased surface areas relatively to the corresponding nonimprinted composites [up to fivefold (from 76 m2 g−1 to 360 m2 g−1) for fucoidan (Fuc) and up to twofold (from 208 m2 g−1 to 351 m2 g−1) for chondroitin sulfate (CS) composites], the diminishing of mean pore size (from 3.3–4.6 nm to 2.9–3.4), and higher biopolymer contents (from mass fractions of 0.42–0.52 to 0.46–0.68). The sorption features depended a great deal on the biopolymer/DES combination. The best CS composite, allowed for 12% capacity and 20% binding strength, as well as Pb(II)/Cd(II) selectivity enhancements. The largest of the capacities was obtained with the imprinted Fuc/DES‐E composite, 86 mg g−1, a 10% increase. Concerning the selectivity [Pb(II) versus Cd(II)], there was a significant increase for the CS composites (from 1.0–1.1 (αqmax)/1.1–1.2 (αK) to 1.3–1.4 (αqmax)/1.3–1.6 (αK)]. In particular, the DES‐E CIC presented high selectivity factors (αqmax 3.0/αK 3.2) in line with those of the microporous version (αqmax 2.0/αK 3.3) but showing a significant increase in terms of the αqmax selectivity. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48842.

ACS Style

Vanessa Regina Azevedo Ferreira; M. A. Azenha; Carlos Pereira; A Fernando Silva. Cation‐bioimprinted mesoporous polysaccharide/sol–gel composites prepared in media containing choline chloride‐based deep eutectic solvents. Journal of Polymer Science 2019, 137, 1 .

AMA Style

Vanessa Regina Azevedo Ferreira, M. A. Azenha, Carlos Pereira, A Fernando Silva. Cation‐bioimprinted mesoporous polysaccharide/sol–gel composites prepared in media containing choline chloride‐based deep eutectic solvents. Journal of Polymer Science. 2019; 137 (26):1.

Chicago/Turabian Style

Vanessa Regina Azevedo Ferreira; M. A. Azenha; Carlos Pereira; A Fernando Silva. 2019. "Cation‐bioimprinted mesoporous polysaccharide/sol–gel composites prepared in media containing choline chloride‐based deep eutectic solvents." Journal of Polymer Science 137, no. 26: 1.

Journal article
Published: 13 December 2019 in Sensors
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A sensing configuration for the real-time monitoring, detection, and quantification of dissolved carbon dioxide (dCO2) was developed for aquaculture and other applications in freshwater and saline water. A chemical sensing membrane, based on a colorimetric indicator, is combined with multimode optical fiber and a dual wavelength light-emitting diode (LED) to measure the dCO2-induced absorbance changes in a self-referenced ratiometric scheme. The detection and processing were achieved with an embeded solution having a mini spectrometer and microcontroller. For optrode calibration, chemical standard solutions using sodium carbonate in acid media were used. Preliminary results in a laboratory environment showed sensitivity for small added amounts of CO2 (0.25 mg·L−1). Accuracy and response time were not affected by the type of solution, while precision was affected by salinity. Calibration in freshwater showed a limit of detection (LOD) and a limit of quantification (LOQ) of 1.23 and 1.87 mg·L−1, respectively. Results in saline water (2.5%) showed a LOD and LOQ of 1.05 and 1.16 mg·L−1, respectively. Generally, performance was improved when moving from fresh to saline water. Studies on the dynamics of dissolved CO2 in a recirculating shallow raceway system (SRS+RAS) prototype showed higher precision than the tested commercial sensor. The new sensor is a compact and robust device, and unlike other sensors used in aquaculture, stirring is not required for correct and fast detection. Tests performed showed that this new sensor has a fast accurate detection as well as a strong potential for assessing dCO2 dynamics in aquaculture applications.

ACS Style

J.P. Mendes; L. Coelho; B. Kovacs; J.M.M.M. De Almeida; C.M. Pereira; P.A.S. Jorge; M.T. Borges. Dissolved Carbon Dioxide Sensing Platform for Freshwater and Saline Water Applications: Characterization and Validation in Aquaculture Environments. Sensors 2019, 19, 5513 .

AMA Style

J.P. Mendes, L. Coelho, B. Kovacs, J.M.M.M. De Almeida, C.M. Pereira, P.A.S. Jorge, M.T. Borges. Dissolved Carbon Dioxide Sensing Platform for Freshwater and Saline Water Applications: Characterization and Validation in Aquaculture Environments. Sensors. 2019; 19 (24):5513.

Chicago/Turabian Style

J.P. Mendes; L. Coelho; B. Kovacs; J.M.M.M. De Almeida; C.M. Pereira; P.A.S. Jorge; M.T. Borges. 2019. "Dissolved Carbon Dioxide Sensing Platform for Freshwater and Saline Water Applications: Characterization and Validation in Aquaculture Environments." Sensors 19, no. 24: 5513.

Journal article
Published: 08 December 2019 in Materials
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Novel C60 and C70 N-methyl-fulleropyrrolidine derivatives, containing both electron withdrawing and electron donating substituent groups, were synthesized by the well-known Prato reaction. The corresponding highest occupied molecular orbital (HOMO)/lowest unoccupied molecular orbital (LUMO) energy levels were determined by cyclic voltammetry, from the onset oxidation and reduction potentials, respectively. Some of the novel fullerenes have higher LUMO levels than the standards PC61BM and PC71BM. When tested in PffBT4T-2OD based polymer solar cells, with the standard architecture ITO/PEDOT:PSS/Active-Layer/Ca/Al, these fullerenes do not bring about any efficiency improvements compared to the standard PC71BM system, however they show how the electronic nature of the different substituents strongly affects the efficiency of the corresponding organic photovoltaic (OPV) devices. The functionalization of C70 yields a mixture of regioisomers and density functional theory (DFT) calculations show that these have systematically different electronic properties. This electronic inhomogeneity is likely responsible for the lower performance observed in devices containing C70 derivatives. These results help to understand how new fullerene acceptors can affect the performance of OPV devices.

ACS Style

Hugo Gaspar; Flávio Figueira; Karol Strutyński; Manuel Melle-Franco; Dzmitry Ivanou; João P. C. Tomé; Carlos M. Pereira; Luiz Pereira; Adélio Mendes; Júlio C. Viana; Gabriel Bernardo. PffBT4T-2OD Based Solar Cells with Aryl-Substituted N-Methyl-Fulleropyrrolidine Acceptors. Materials 2019, 12, 4100 .

AMA Style

Hugo Gaspar, Flávio Figueira, Karol Strutyński, Manuel Melle-Franco, Dzmitry Ivanou, João P. C. Tomé, Carlos M. Pereira, Luiz Pereira, Adélio Mendes, Júlio C. Viana, Gabriel Bernardo. PffBT4T-2OD Based Solar Cells with Aryl-Substituted N-Methyl-Fulleropyrrolidine Acceptors. Materials. 2019; 12 (24):4100.

Chicago/Turabian Style

Hugo Gaspar; Flávio Figueira; Karol Strutyński; Manuel Melle-Franco; Dzmitry Ivanou; João P. C. Tomé; Carlos M. Pereira; Luiz Pereira; Adélio Mendes; Júlio C. Viana; Gabriel Bernardo. 2019. "PffBT4T-2OD Based Solar Cells with Aryl-Substituted N-Methyl-Fulleropyrrolidine Acceptors." Materials 12, no. 24: 4100.

Journal article
Published: 27 November 2019 in Coatings
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Nano carbons, such as graphene and carbon nanotubes, show very interesting electrochemical properties and are becoming a focus of interest in many areas, including electrodeposition of carbon–metal composites for battery application. The aim of this study was to incorporate carbon materials (namely oxidized multi-walled carbon nanotubes (ox-MWCNT), pristine multi-walled carbon nanotubes (P-MWCNT), and reduced graphene oxide (rGO)) into a metallic tin matrix. Formation of the carbon–tin composite materials was achieved by electrodeposition from a choline chloride-based ionic solvent. The different structures and treatments of the carbon materials will create metallic composites with different characteristics. The electrochemical characterization of Sn and Sn composites was performed using chronoamperometry, potentiometry, electrochemical impedance, and cyclic voltammetry. The initial growth stages of Sn and Sn composites were characterized by a glassy-carbon (GC) electrode surface. Nucleation studies were carried out, and the effect of the carbon materials was characterized using the Scharifker and Hills (SH) and Scharifker and Mostany (SM) models. Through a non-linear fitting method, it was shown that the nucleation of Sn and Sn composites on a GC surface occurred through a 3D instantaneous process with growth controlled by diffusion. According to Raman and XRD analysis, carbon materials were successfully incorporated at the Sn matrix. AFM and SEM images showed that the carbon incorporation influences the coverage of the surface as well as the size and shape of the agglomerate. From the analysis of the corrosion tests, it is possible to say that Sn-composite films exhibit a comparable or slightly better corrosion performance as compared to pure Sn films.

ACS Style

Ana T. S. C. Brandão; Liana Anicai; Oana Andreea Lazar; Sabrina Rosoiu; Aida Pantazi; Renata Costa; Marius Enachescu; Carlos M. Pereira; A. Fernando Silva. Electrodeposition of Sn and Sn Composites with Carbon Materials Using Choline Chloride-Based Ionic Liquids. Coatings 2019, 9, 798 .

AMA Style

Ana T. S. C. Brandão, Liana Anicai, Oana Andreea Lazar, Sabrina Rosoiu, Aida Pantazi, Renata Costa, Marius Enachescu, Carlos M. Pereira, A. Fernando Silva. Electrodeposition of Sn and Sn Composites with Carbon Materials Using Choline Chloride-Based Ionic Liquids. Coatings. 2019; 9 (12):798.

Chicago/Turabian Style

Ana T. S. C. Brandão; Liana Anicai; Oana Andreea Lazar; Sabrina Rosoiu; Aida Pantazi; Renata Costa; Marius Enachescu; Carlos M. Pereira; A. Fernando Silva. 2019. "Electrodeposition of Sn and Sn Composites with Carbon Materials Using Choline Chloride-Based Ionic Liquids." Coatings 9, no. 12: 798.

Journal article
Published: 01 November 2019 in Analytica Chimica Acta
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Considering the high incidence level and mortality rate of ovarian cancer, particularly among the European female population, the carbohydrate antigen 125 (CA-125) was selected as the protein target for this study for the development of a MIP-based biosensor. This work presents the development of molecular imprinting polymers (MIPs) on gold electrode surface for CA-125 biomarker recognition. The preparation of the CA-125 imprinting was obtained by electropolymerization of pyrrole (Py) monomer in a gold electrode using cyclic voltammetry (CV) in order to obtain highly selective materials with great molecular recognition capability. The quantification of CA-125 biomarker was made through the comparison of two methods: electrochemical (square wave voltammetry -SWV) and optical transduction (surface plasmon resonance -SPR). SWV has been widely used in biological molecules analysis since it is a fast and sensitive technique. In turn, SPR is a non-destructive optical technique that provides high-quality analytical data of CA-125 biomarker interactions with MIP. Several analytical parameters, such as sensitivity, linear response interval, and detection limit were determined to proceed to the performance evaluation of the electrochemical and optical transduction used in the development of the CA-125 biosensor. The biosensor based in the electrochemical transduction was the one that presented the best analytical parameters, yielding a good selectivity and a detection limit (LOD) of 0.01 U/mL, providing a linear concentration range between 0.01 and 500 U/mL. This electrochemical biosensor was selected for the study and it was successfully applied in the CA-125 analysis in artificial serum samples with recovery rates ranging from 91 to 105% with an average relative error of 5.8%.

ACS Style

Tânia Rebelo; Renata Costa; Ana T.S.C. Brandão; A Fernando Silva; M. Goreti F. Sales; Carlos M. Pereira. Molecularly imprinted polymer SPE sensor for analysis of CA-125 on serum. Analytica Chimica Acta 2019, 1082, 126 -135.

AMA Style

Tânia Rebelo, Renata Costa, Ana T.S.C. Brandão, A Fernando Silva, M. Goreti F. Sales, Carlos M. Pereira. Molecularly imprinted polymer SPE sensor for analysis of CA-125 on serum. Analytica Chimica Acta. 2019; 1082 ():126-135.

Chicago/Turabian Style

Tânia Rebelo; Renata Costa; Ana T.S.C. Brandão; A Fernando Silva; M. Goreti F. Sales; Carlos M. Pereira. 2019. "Molecularly imprinted polymer SPE sensor for analysis of CA-125 on serum." Analytica Chimica Acta 1082, no. : 126-135.

Journal article
Published: 25 October 2019 in Journal of Molecular Liquids
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New molecular dynamics (MD) simulations and experimental data on a deep eutectic solvent, propeline, composed by choline chloride, ChCl, and propylene glycol, PG, in a molar ratio of 1:2 are reported in this work. The experimental physicochemical properties (density, viscosity and self-diffusion coefficients) were used as support in the development of a new OPLS based force field model (FFM) for propeline. Validation of the new force field was established both through measuring physicochemical properties over a range of temperatures (298.15–373.15 K) and by comparison with experimental and simulated data of ethaline (ChCl:ethylene glycol, at a molar ration of 1:2). Classical MD simulations using the new FFM led to good agreement between experimental and simulated data. Structural properties, namely radial and spatial distribution functions, coordination numbers, and hydrogen bonding were analyzed. Moreover, it was found that the interactions between the anion, Cl−, and the hydrogen bond donor (HBD) form a network that is immutable with increasing temperature. The higher prevalence of anion-HBD hydrogen bonds is likely the major reason for the relatively high viscosity of propeline.

ACS Style

Elisabete S.C. Ferreira; Iuliia V. Voroshylova; Nádia M. Figueiredo; Carlos M. Pereira; M. Natália D.S. Cordeiro. Computational and experimental study of propeline: A choline chloride based deep eutectic solvent. Journal of Molecular Liquids 2019, 298, 111978 .

AMA Style

Elisabete S.C. Ferreira, Iuliia V. Voroshylova, Nádia M. Figueiredo, Carlos M. Pereira, M. Natália D.S. Cordeiro. Computational and experimental study of propeline: A choline chloride based deep eutectic solvent. Journal of Molecular Liquids. 2019; 298 ():111978.

Chicago/Turabian Style

Elisabete S.C. Ferreira; Iuliia V. Voroshylova; Nádia M. Figueiredo; Carlos M. Pereira; M. Natália D.S. Cordeiro. 2019. "Computational and experimental study of propeline: A choline chloride based deep eutectic solvent." Journal of Molecular Liquids 298, no. : 111978.