@article{Salonen2018,
title = {Adsorption of Pharmaceutical Pollutants from Water Using Covalent Organic Frameworks},
author = {Abdelkarim Mellah; Soraia P. S. Fernandes; Ramón Rodríguez; José Otero; Jairo Paz; Jacobo Cruces; Dana D. Medina; Harik Djamila; Begoña Espiña; Laura M. Salonen},
url = {https://doi.org/10.1002/chem.201801649},
doi = {10.1002/chem.201801649},
year = {2018},
date = {2018-06-12},
journal = {Chemical European Journal},
abstract = {Capture of pharmaceutical pollutants from water was studied using a novel fluorine‐bearing covalent organic framework TpBD‐(CF3)2, which showed ibuprofen adsorption capacity of 119 mg g‐1 at neutral pH. This value is further enhanced at pH 2, highlighting the potential of this class of materials to serve as adsorbents even under harsh conditions. The adsorbed pharmaceutical can be recovered from TpBD‐(CF3)2 in high yield, offering the option of recycling both the adsorbent and the pharmaceutical. The high efficiency of ibuprofen capture as compared to other less lipophilic pharmaceuticals suggests that COFs can be pre‐designed for selective capture of contaminants. },
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Freitas2018,
title = {Custom Magnet Design for a Multi-Channel Magnetic Microcytometer},
author = {Alexandre Chicharo ; L. C. Barnsley ; Marco Martins ; Susana Cardoso ; Lorena Diéguez ; Begoña Espiña ; P. P. Freitas},
url = {https://ieeexplore.ieee.org/document/8379352/},
doi = {10.1109/TMAG.2018.2835369},
issn = {1941-0069},
year = {2018},
date = {2018-06-11},
journal = {IEEE Transactions on Magnetics },
volume = {54},
number = {11},
abstract = {Magnetic microflow cytometers integrate magnetic field sensors and microfluidic channels to detect cell suspensions labeled with magnetic beads. As the magnetic beads are superparamagnetic, commercial permanent magnets (PMs) are typiacally positioned bellow the microchip for an out-of-plane magnetization. Though, they require careful alignment as their magnetic field can impact the sensors sensitivity. In this paper, we overcome this drawback by presenting an innovative custom-made PM that notably combines high out-of-plane magnetic field (>100 mT) and low in-plane magnetic field (<1 mT) over a large area (30.2 mm²). This configuration qualifies the setup for simultaneous detection in multiple microfluidic channels within the same microchip, allowing parallel analysis of different cell samples or faster analysis of larger volumes of cell suspension.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Vasimalai2018,
title = {Green synthesis of fluorescent carbon dots from spices for in vitro imaging and tumour cell growth inhibition},
author = {Nagamalai Vasimalai and Vânia Vilas-Boas and Juan Gallo and María de Fátima Cerqueira and Mario Menéndez-Miranda and José Manuel Costa-Fernández and Lorena Diéguez and Begoña Espiña and María Teresa Fernández-Argüelles.},
url = {https://www.beilstein-journals.org/bjnano/articles/9/51},
doi = {doi:10.3762/bjnano.9.51},
year = {2018},
date = {2018-02-13},
journal = {BEILSTEIN JOURNAL OF NANOTECHNOLOGY},
volume = {9},
pages = {530-544},
abstract = {Carbon dots have demonstrated great potential as luminescent nanoparticles in bioapplications. Although such nanoparticles appear to exhibit low toxicity compared to other metal luminescent nanomaterials, today we know that the toxicity of carbon dots (C-dots) strongly depends on the protocol of fabrication. In this work, aqueous fluorescent C-dots have been synthesized from cinnamon, red chilli, turmeric and black pepper, by a one-pot green hydrothermal method. The synthesized C-dots were firstly characterized by means of UV–vis, fluorescence, Fourier transform infrared and Raman spectroscopy, dynamic light scattering and transmission electron microscopy. The optical performance showed an outstanding ability for imaging purposes, with quantum yields up to 43.6%. Thus, the cytotoxicity of the above mentioned spice-derived C-dots was evaluated in vitro in human glioblastoma cells (LN-229 cancer cell line) and in human kidney cells (HK-2 non-cancerous cell line). Bioimaging and viability studies were performed with different C-dot concentrations from 0.1 to 2 mg·mL−1, exhibiting a higher uptake of C-dots in the cancer cultures compared to the non-cancerous cells. Results showed that the spice-derived C-dots inhibited cell viability dose-dependently after a 24 h incubation period, displaying a higher toxicity in LN-229, than in HK-2 cells. As a control, C-dots synthesized from citric acid did not show any significant toxicity in either cancerous or non-cancerous cells, implying that the tumour cell growth inhibition properties observed in the spice-derived C-dots can be attributed to the starting material employed for their fabrication. These results evidence that functional groups in the surface of the C-dots might be responsible for the selective cytotoxicity, as suggested by the presence of piperine in the surface of black pepper C-dots analysed by ESI-QTOF-MS.

Keywords: bioimaging; carbon quantum dots; fluorescence; spices },
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Vilas-Boas2018,
title = {Combining CXCR4-targeted and nontargeted nanoparticles for effective unassisted in vitro magnetic hyperthermia },
author = {Vânia Vilas-Boas and Begoña Espiña and Yury V. Kolen'ko and Manuel Bañobre-Lopez and José A. Duarte and Verónica C. Martins and Dmitri Y. Petrovykh and Paulo P. Freitas and Felix D. Carvalho},
url = {https://avs.scitation.org/doi/10.1116/1.5009989},
doi = {10.1116/1.5009989 },
year = {2018},
date = {2018-01-15},
journal = {Biointerphases},
volume = {13},
number = {1},
abstract = {The use of targeted nanoparticles for magnetic hyperthermia (MHT) increases MHT selectivity, but often at the expense of its effectiveness. Consequently, targeted MHT is typically used in combination with other treatment modalities. This work describes an implementation of a highly effective monotherapeutic in vitro MHT treatment based on two populations of magnetic particles. Cells were sequentially incubated with two populations of magnetic particles: nonfunctionalized superparamagnetic nanoparticles and anti-CXCR4-functionalized particles. After removing the excess of free particles, an alternating magnetic field (AMF) was applied to produce MHT. The induced cytotoxicity was assessed at different time-points after AMF application. Complete loss of cell viability was observed 72 h after MHT when the iron loading of the anti-CXCR4-functionalized particles was boosted by that of a nontargeted population. Additionally, induction of necrosis resulted in more efficient cell death than did induction of apoptosis. Achieving a uniquely high effectiveness in monotherapeutic MHT demonstrates the potential of this approach to achieve complete loss of viability of cancer cells while avoiding the side effects of dual-treatment strategies that use MHT only as a sensitizing therapy.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Vasimalai2017,
title = {Detection of sulfide using mercapto tetrazine protected fluorescent gold nanodots: The preparation of paper based testing kit for on-site monitoring},
author = {Vasimalai N, Fernández-Argüelles MT, Espiña B.},
url = {https://www.ncbi.nlm.nih.gov/pubmed/29271189},
doi = {10.1021/acsami.7b11769},
year = {2017},
date = {2017-12-22},
journal = {ACS Appl Mater Interfaces},
abstract = {This work demonstrates the development of a highly sensitive method to detect and quantify the sulfide ions (S2-) in water samples. First, we synthesized 6-mercapto-s-triazolo(4,3-b)-s-tetrazine (MTT) by the reaction between formaldehyde and 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole at room temperature. The synthetic MTT was used as a capping ligand for the synthesis of gold nanodots (AuNDs) via one-pot green method at room temperature with only a 10 min reaction time. TEM images exhibited that the MTT-AuNDs has an average particle size of 1.9 nm and an emission maximum at 672 nm upon excitation at 360 nm. The synthesized highly red emissive MTT-AuNDs are used as specific fluorescent probes for the detection of S2-. The fluorescence of MTT-AuNDs was significantly and dose-dependently quenched from the addition of S2-. The observed fluorescence quenching was ascribed to the formation of an Au2S complex, which was determined by Raman and mass spectroscopy. A good linearity was achieved for the increasing concentration of S2- from 870 nM to 16 µM and the detection limit (LOD) was found to be 2 nM (S/N = 3). The S2- detection system that is described in this study was validated and agreed well with the standard methylene blue method. Furthermore, the present sensor was examined for the use in quantifying S2- in real water samples obtained from lake and river. In addition, the specificity was checked against the most likely ion interferences in real water. Moreover, a cost-effective and viable paper based S2- sensor was fabricated for environmental monitoring based on the use of MTT-AuNDs. The developed system would be an environmentally friendly and easy to use detection device for S2- in water.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Salonen2017,
title = {Adsorption of marine phycotoxin okadaic acid on a covalent organic framework},
author = {L. M. Salonen, S. R. Pinela, S. P. S Fernandes, J. Louçano, E. Carbó-Argibay, M.P. Sarria, C. Rodríguez-Abreu, J. Peixoto, B. Espiña.},
url = {https://www.ncbi.nlm.nih.gov/pubmed/29037592},
doi = {10.1016/j.chroma.2017.10.017 },
year = {2017},
date = {2017-11-24},
journal = {J Chromatogr A.},
volume = {1525:17-22},
abstract = {Phycotoxins, compounds produced by some marine microalgal species, can reach high concentrations in the sea when a massive proliferation occurs, the so-called harmful algal bloom. These compounds are especially dangerous to human health when concentrated in the digestive glands of seafood. In order to generate an early warning system to alert for approaching toxic outbreaks, it is very important to improve monitoring methods of phycotoxins in aquatic ecosystems. Solid-phase adsorption toxin tracking devices reported thus far based on polymeric resins have not been able to provide an efficient harmful algal bloom prediction system due to their low adsorption capabilities. In this work, a water-stable covalent organic framework (COF) was evaluated as adsorbent for the hydrophobic toxin okadaic acid, one of the most relevant marine toxins and the parental compound of the most common group of toxins responsible for the diarrhetic shellfish poisoning. Adsorption kinetics of okadaic acid onto the COF in seawater showed that equilibrium concentration was reached in only 60min, with a maximum experimental adsorption of 61mgg-1. Desorption of okadaic acid from the COF was successful with both 70% ethanol and acetonitrile as solvent, and the COF material could be reused with minor losses in adsorption capacity for three cycles. The results demonstrate that COF materials are promising candidates for solid-phase adsorption in water monitoring devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Viegas2017,
title = {Adapting Bobbert-Vlieger model to spectroscopic ellipsometry of gold nanoparticles with bio-organic shells},
author = {D Viegas, E Fernandes, R Queirós, DY Petrovykh and PAA De Beule},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5560823/},
doi = {10.1364/BOE.8.003538},
year = {2017},
date = {2017-08-01},
journal = {Biomed Opt Express},
volume = {8},
pages = {3538–3550},
abstract = {We investigate spectroscopic imaging ellipsometry for monitoring biomolecules at surfaces of nanoparticles. For the modeling of polarimetric light scattering off surface-adsorbed core-shell nanoparticles, we employ an extension of the exact solution for the scattering by particles near a substrate presented by Bobbert and Vlieger, which offers insight beyond that of the Maxwell-Garnett effective medium approximation. Varying thickness and refractive index of a model bio-organic shell results in systematic and characteristic changes in spectroscopic parameters Ψ and Δ. The salient features and trends in modeled spectra are in qualitative agreement with experimental data for antibody immobilization and fibronectin biorecognition at surfaces of gold nanoparticles on a silicon substrate, but achieving a full quantitative agreement will require including additional effects, such as nanoparticle-substrate interactions, into the model.
OCIS codes: (120.2130) Ellipsometry and polarimetry, (240.6680) Surface plasmons, (280.1415) Biological sensing and sensors, (280.4788) Optical sensing and sensors},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@inbook{Prado2016b,
title = {Detection of Foodborne Pathogens Using Nanoparticles. Advantages and Trends},
author = {Prado, M.; Espiña, B.; Fernandez-Arguelles, M. T.; Diéguez, L.; Fuciños, P.; Vial, S.; Oliveira, J. M.; Reis, R. L.; Boehme, K.},
url = {https://www.sciencedirect.com/science/book/9780128007235},
isbn = {978-0-12-800723-5},
year = {2016},
date = {2016-12-01},
booktitle = {Antimicrobial Food Packaging},
journal = {Academic Press, London},
pages = {pp.183-202},
publisher = {Jorge Barros-Velazquez},
edition = {1st Edition},
abstract = {Due to their critical impact on public health, the detection of foodborne pathogens in food and water is an important issue for both, the food industry and control authorities. Fast and reliable analytical methods are needed in order to ensure the health of consumers, to easily determine whether a food product has been subjected to cross-contamination, and, simultaneously, to identify how and when this cross-contamination occurred in order to establish the proper corrective actions.Recent developments in nanotechnology are greatly impacting the advancement of some analytical techniques, including foodborne pathogen detection. Herein, the advantages and the recent applications of nanoparticles (NPs) in foodborne pathogen detection are reviewed. The most frequently used NPs in this context (gold nanoparticles, quantum dots, and magnetic nanoparticles) are described, and their applicability for food analysis is emphasized. Finally, this chapter provides an overview of the use of micro and nanofluidics, combined with nanoparticles, for food pathogen analysis, and the integration of nanomaterial-based sensors for pathogen detection in food packaging systems.
},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
}

@article{J2016,
title = {Green synthesis of multimodal 'OFF-ON' activatable MRI/optical probes},
author = {Gallo J, Vasimalai N, Fernandez-Arguelles MT, Bañobre-López M.},
url = {https://www.ncbi.nlm.nih.gov/pubmed/27752669},
doi = {10.1039/c6dt02840c},
year = {2016},
date = {2016-11-28},
journal = {Dalton Trans.},
volume = {45},
pages = {17672-17680},
abstract = {Diagnosis by MRI is frequently non-trivial due to the low sensitivity of the technique. Signal enhancing contrast agents (CAs) are used to aid in the analysis of MR images. We present here a simple protocol for the preparation of responsive CAs based on Mn nanosheets. Mn nanostructures presented here undergo a chemical and structural change in the presence of altered physiological conditions that activate their signal. This strategy allows for a reduction of background, increasing the sensitivity of the technique. The simple synthetic protocol followed allows for the combination of the nanosheets with reporter molecules for other imaging techniques, like carbon quantum dots for optical imaging.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Vasimalai2016,
title = {Novel one-pot and facile room temperature synthesis of gold nanodots and application as highly sensitive and selective probes for cyanide detection},
author = {N. Vasimalai and Maria T. Fernández-Argüelles*. },
url = {https://www.ncbi.nlm.nih.gov/pubmed/27779114},
doi = {10.1088/0957-4484/27/47/475505 },
year = {2016},
date = {2016-11-01},
journal = {Nanotechnology},
volume = {Volume 27},
number = {Issue 47},
pages = { article id. 475505},
abstract = {Highly fluorescent gold nanodots have been synthesized through a novel rapid, facile and one-pot room temperature route using trithiocyanuric acid as mild reducing agent and surface ligand. The proposed synthesis overcomes limitations of other synthetic routes in terms of cost, time, complexity and environmental risks, and gives rise to highly fluorescent gold nanodots within 10 min at room temperature, with a maximum emission wavelength at 623 nm and a large Stokes shift (213 nm). Moreover, the synthesized gold nanodots showed a large emission QY (9.62 × 10-2) and excellent photostability and colloidal properties during long periods. Increasing concentrations of CN- in aqueous solution progressively quenched the fluorescence emission and produced a slight blue shift of the synthesized gold nanodots. A good linear relationship was observed for CN- concentrations between 0.29 and 8.87 μM, obtaining a detection limit estimated according to the 3s IUPAC criteria of 150 nM. Besides, the influence on the fluorescence signal of potential interferents at high concentrations (1000 μM) was studied, including I-, F-, citrate, {{{{PO}}}4}3-, {{{{NO}}}3}-, {{{{SO}}}4}2-, CH3COO-, EDTA, Br-, {{{{CO}}}3}2-, Cl- and S2- K+, Na+, Li+, Mg2+, Ca2+, Ba2+, Cu2+, Zn2+, Ni2+, Al3+, Fe2+, Fe3+, Pb2+, Cd2+, Hg2+ and Co2+. Results showed a high selectivity towards all the investigated ions, except for Pb2+, Cd2+ and Hg2+, although the use of glutathione and BSA as masking agents drastically minimized the effect of such cations at high concentrations. The synthesized gold nanodots were successfully evaluated as highly sensitive and selective probes for cyanide determination in environmental water samples, including tap, river, lake and sea water, indicating the validity of TCA-AuNDs for analytical CN- contamination control.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{Oliveira2016,
title = {Counter ions and constituents combination affect DODAX:MO nanocarriers toxicity in vitro and in vivo},
author = {C.N. Oliveira, M.P. Sarria, P. Moreira, J. Fernandes, L. Castro, I. Lopes, M. Corte-Real, A. Cavaco-Paulo, M.E.C.D. Real Oliveira, A.C. Gomes},
url = {http://pubs.rsc.org/-/content/articlelanding/2016/tx/c6tx00074f/unauth#!divAbstract},
doi = {10.1039/C6TX00074F},
year = {2016},
date = {2016-06-13},
journal = {Toxicology Research },
volume = {5},
number = {Issue 4},
pages = {1244-1255 },
abstract = {Liposomes have received extensive attention as nanocarriers for bioactive compounds due to their good biocompatibility, possibility of targeting and incorporation of hydrophilic and hydrophobic compounds. Although generally considered as safe, detailed knowledge of the effects induced in cells and tissues with which they interact is still underexplored. The aim of this study is to gain insight into the toxicity profile of dioctadecyldimethylammonium (DODAX) : monoolein(MO) liposomes (X is bromide or chloride), previously validated for gene therapy, by evaluating the effect of the counter ions Br− or Cl−, and of the cationic : neutral lipid molar fraction, both in vitro and in vivo. Effects on cellular metabolism and proliferation, plasma membrane integrity, oxidative stress, mitochondrial membrane potential dysfunction and ability to trigger apoptosis and necrosis were evaluated in a dose-/time-dependent manner in normal human skin fibroblasts. Also, newly fertilized zebrafish zygotes were exposed to liposomes, permitting a fast-track evaluation of the morphophysiological modifications. In vitro data showed that only very high doses of DODAX : MO induce apoptosis and necrosis, inhibit cell proliferation, and affect the metabolism and plasma membrane integrity of fibroblasts in a dose-/time-dependent manner. Furthermore, liposomes affected mitochondrial function, increasing ROS accumulation and disturbing mitochondrial membrane potential. DODAC-based liposomes were consistently more toxic when compared to DODAB-based formulations; furthermore, the inclusion of MO was found to reduce toxicity, in contrast to liposomes with cationic DODAX only, especially in DODAB : MO (1 : 2) nanocarriers. These results were corroborated, in a holistic approach, by cytotoxicity profiling in five additional human cell lines, and also with the zebrafish embryotoxicity testing, which constitutes a sensitive and informative tool and accurately extends cell-based assays.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}