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[EN] Gold nanoparticles functionalized with resorcinol moieties have been prepared and used for detecting formaldehyde both in solution and gas phases. The detection mechanism is based on the color change of the probe upon the aggregation of the nanoparticles induced by the polymerization of the resorcinol moieties in the presence of formaldehyde. A limit of detection of 0.5 ppm in solution has been determined. The probe can be deployed for the detection of formaldehyde emissions from composite wood boards. ; We thank the Spanish Government (projects MAT2015-64139-C4-4-R and AGL2015-70235-C2-2-R (MINECO/FEDER)) and the Generalitat Valenciana (project PROMETEOII/2014/047) for support. ; Martínez-Aquino, C.; Costero, AM.; Gil Grau, S.; Gaviña, P. (2019). Resorcinol Functionalized Gold Nanoparticles for Formaldehyde Colorimetric Detection. Nanomaterials. 9(2):1-9. https://doi.org/10.3390/nano9020302 ; S ; 1 ; 9 ; 9 ; 2 ; Salthammer, T. (2013). Formaldehyde in the Ambient Atmosphere: From an Indoor Pollutant to an Outdoor Pollutant? Angewandte Chemie International Edition, 52(12), 3320-3327. doi:10.1002/anie.201205984 ; Bruemmer, K. J., Brewer, T. F., & Chang, C. J. (2017). Fluorescent probes for imaging formaldehyde in biological systems. Current Opinion in Chemical Biology, 39, 17-23. doi:10.1016/j.cbpa.2017.04.010 ; Lang, I., Bruckner, T., & Triebig, G. (2008). Formaldehyde and chemosensory irritation in humans: A controlled human exposure study. Regulatory Toxicology and Pharmacology, 50(1), 23-36. doi:10.1016/j.yrtph.2007.08.012 ; IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Vol. 100F (2012). Chemical Agents and Related Occupations: Formaldehydehttps://monographs.iarc.fr/wp-content/uploads/2018/06/mono100F-29.pdf ; Chung, P.-R., Tzeng, C.-T., Ke, M.-T., & Lee, C.-Y. (2013). Formaldehyde Gas Sensors: A Review. Sensors, 13(4), 4468-4484. doi:10.3390/s130404468 ; Soman, A., Qiu, Y., & Chan Li, Q. (2008). HPLC-UV Method Development and Validation for the Determination of Low ...

A limiting factor of solvent‐induced nanoparticle self‐assembly is the need for constant sample dilution in assembly/disassembly cycles. Changes in the nanoparticle concentration alter the kinetics of the subsequent assembly process, limiting optical signal recovery. Herein, we show that upon confining hydrophobic nanoparticles in permeable silica nanocapsules, the number of nanoparticles participating in cyclic aggregation remains constant despite bulk changes in solution, leading to highly reproducible plasmon band shifts at different solvent compositions. ; L.M.L.-M. and M.G. acknowledge funding from the Spanish MINECO (Grant #MAT2013-46101R). N.C. and S.B. acknowledge financial support from European Research Council (ERC Starting Grant #335078-COLOURATOM). D.M.S., and J.M.T, acknowledge funding from the European Regional Development Fund (ERDF) and the Spanish MINECO (Projects TEC2017-85376-C2-1-R, TEC2017-85376-C2-2-R), and from the ERDF and the Galician Regional Government under agreement for funding the Atlantic Research Center for Information and Communication Technologies (AtlantTIC).

[EN] Propiolates cyclotrimerize in the presence of catalytic amounts of gold nanoparticles to give aryl benzoates in high yields and with turnover frequencies of thousands per hour. Types of alkynes other than propiolates do not react, and, if molecular oxygen is present and dissociated by the gold nanoparticles, electron-rich arenes engage with the propiolate to form a new C–C bond. The activation of propiolates and electron-rich arenes to form C–C bonds, beyond gold-catalyzed Michael additions, constitutes a new example of how and where gold nanoparticles modify the electronic density of unsaturated C–C bonds and opens the door to future transformations. ; A.L.-P. thanks CSIC for a contract. J.O.-M. thanks ITQ for a postgraduate scholarship. J.R.C.-A. and P.R.-M. thank MECD for the concession of a FPU contract. Financial support by the Severo Ochoa program and Consolider-Ingenio 2010 (proyecto MULTICAT) from MICIINN is acknowledged, and also the King Saud University. P.S. thanks European Union Seventh Framework programme (PIOF-GA-2009-253129). ; Leyva Perez, A.; Oliver Meseguer, J.; Cabrero Antonino, JR.; Rubio Marqués, P.; Serna, P.; Al-Resayes, SI.; Corma Canós, A. (2013). Reactivity of Electron-Deficient Alkynes on Gold Nanoparticles. ACS Catalysis. 3(8):1865-1873. https://doi.org/10.1021/cs400362c ; S ; 1865 ; 1873 ; 3 ; 8

1 9 2 ; S Chung, P.-R., Tzeng, C.-T., Ke, M.-T., & Lee, C.-Y. (2013). Formaldehyde Gas Sensors: A Review. Sensors, 13(4), 4468-4484. doi:10.3390/s130404468 ; [EN] Gold nanoparticles functionalized with resorcinol moieties have been prepared and used for detecting formaldehyde both in solution and gas phases. The detection mechanism is based on the color change of the probe upon the aggregation of the nanoparticles induced by the polymerization of the resorcinol moieties in the presence of formaldehyde. A limit of detection of 0.5 ppm in solution has been determined. The probe can be deployed for the detection of formaldehyde emissions from composite wood boards. We thank the Spanish Government (projects MAT2015-64139-C4-4-R and AGL2015-70235-C2-2-R (MINECO/FEDER)) and the Generalitat Valenciana (project PROMETEOII/2014/047) for support. Martínez-Aquino, C.; Costero, AM.; Gil Grau, S.; Gaviña, P. (2019). Resorcinol Functionalized Gold Nanoparticles for Formaldehyde Colorimetric Detection. Nanomaterials. 9(2):1-9. https://doi.org/10.3390/nano9020302 Salthammer, T. (2013). Formaldehyde in the Ambient Atmosphere: From an Indoor Pollutant to an Outdoor Pollutant? Angewandte Chemie International Edition, 52(12), 3320-3327. doi:10.1002/anie.201205984 Bruemmer, K. J., Brewer, T. F., & Chang, C. J. (2017). Fluorescent probes for imaging formaldehyde in biological systems. Current Opinion in Chemical Biology, 39, 17-23. doi:10.1016/j.cbpa.2017.04.010 Lang, I., Bruckner, T., & Triebig, G. (2008). Formaldehyde and chemosensory irritation in humans: A controlled human exposure study. Regulatory Toxicology and Pharmacology, 50(1), 23-36. doi:10.1016/j.yrtph.2007.08.012 IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Vol. 100F (2012). Chemical Agents and Related Occupations: Formaldehydehttps://monographs.iarc.fr/wp-content/uploads/2018/06/mono100F-29.pdf Soman, A., Qiu, Y., & Chan Li, Q. (2008). HPLC-UV Method Development and Validation for the Determination of Low Level Formaldehyde in a ...

[EN] Metallic hollow nanoparticles exhibit interesting optical properties that can be controlled by geometrical parameters. Irradiation with femtosecond laser pulses has emerged recently as a valuable tool for reshaping and size modification of plasmonic metal nanoparticles, thereby enabling the synthesis of nanostructures with unique morphologies. In this Letter, we use classical molecular dynamics simulations to investigate the solid-to-hollow conversion of gold nanoparticles upon femtosecond laser irradiation. Here, we suggest an efficient method for producing hollow nanoparticles under certain specific conditions, namely that the particles should be heated to a maximum temperature between 2500 and 3500 K, followed by a fast quenching to room temperature, with cooling rates lower than 120 ps. Therefore, we describe the experimental conditions for efficiently producing hollow nanoparticles, opening a broad range of possibilities for applications in key areas, such as energy storage and catalysis. ; This work has been funded by the Spanish Ministry of Science, Innovation and Universities (MICIU) (Grants RTI2018-095844-B-I00, PGC2018-096444-B-I00, and MAT2017-86659-R), the EUROfusion Consortium through Project ENR-IFE19.CCFE-01, and the Madrid Regional Government (Grants P2018/NMT-4389 and P2018/EMT-4437). A.P. is thankful for the support of FONDECYT under Grants 3190123 and 11180557, as well as from Financiamiento Basal para Centros Cientificos y Tecnologicos de Excelencia FB-0807. K.L. acknowledges the support of the Russian Science Foundation (Project 19-19-00683). The authors acknowledge the computer resources and technical assistance provided by the Centro de Supercomputacion y Visualizacion de Madrid (CeSViMa) and the supercomputing infrastructure of the NLHPC (ECM-02). This Letter is based upon work from COST Action TUMIEE (CA17126) ; Castro-Palacio, JC.; Ladutenko, K.; Prada, A.; Gonzalez-Rubio, G.; Diaz-Nunez, P.; Guerrero-Martinez, A.; Fernández De Córdoba, P. (2020). Hollow Gold Nanoparticles Produced ...

The global economic success of man-made nanoscale materials has led to a higher production rate and diversification of emission sources in the environment. For these reasons, novel nanosafety approaches to assess the environmental impact of engineered nanomaterials are required. While studying the potential toxicity of metal nanoparticles (NPs), we realized that gold nanoparticles (AuNPs) have a growth-promoting rather than a stress-inducing effect. In this study we established stable short-and long-term exposition systems for testing plant responses to NPs. Exposure of plants to moderate concentrations of AuNPs resulted in enhanced growth of the plants with longer primary roots, more and longer lateral roots and increased rosette diameter, and reduced oxidative stress responses elicited by the immune-stimulatory PAMP flg22. Our data did not reveal any detri-mental effects of AuNPs on plants but clearly showed positive effects on growth, presumably by their protective influence on oxidative stress responses. Differential transcriptomics and proteomics analyses revealed that oxidative stress responses are downregulated whereas growth-promoting genes/proteins are upregulated. These omics datasets after AuNP exposure can now be exploited to study the underlying molecular mechanisms of AuNP-induced growth-promotion. ; This research received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement PANDORA, no. 671881.

Despite the obvious advantages of gold nanoparticles for biomedical applications, controversial and incomplete toxicological data hamper their widespread use. Here, we present the results from an in vivo toxicity study using gold nanoparticles coated with polyethylene glycol (PEG-AuNPs). The pharmacokinetics and biodistribution of PEG-AuNPs were examined in the rat's liver, lung, spleen, and kidney after a single i.v. injection (0.7 mg/kg) at different time intervals. PEG-AuNPs had a relatively long blood circulation time and accumulated primarily in the liver and spleen, where they remained for up to 28 days after administration. Increased cytoplasmic vacuolation in hepatocytes 24 h and 7 days after PEG-AuNPs exposure and apoptotic-like cells in white splenic pulp 24 h after administration has been detected, however, 28 days post-exposure were no longer observed. In contrast, at this time point, we identified significant changes in lipid metabolism, altered levels of liver injury markers, and elevated monocyte count, but without marked biological relevance. In blood cells, no DNA damage was present in any of the studied time intervals, with the exception of DNA breakage transiently detected in primary kidney cells 4 h post-injection. Our results indicate that the tissue accumulation of PEG-AuNPs might result in late toxic effects. ; This paper is supported by European Union's Horizon 2020 research and innovation program under grant agreement No. 857381, project VISION (Strategies to strengthen scientific excellence and innovation capacity for early diagnosis of gastrointestinal cancers), project HISENTS No. 685817, VEGA grants 2/0055/20, 2/0121/21.

Despite the obvious advantages of gold nanoparticles for biomedical applications, controversial and incomplete toxicological data hamper their widespread use. Here, we present the results from an in vivo toxicity study using gold nanoparticles coated with polyethylene glycol (PEG-AuNPs). The pharmacokinetics and biodistribution of PEG-AuNPs were examined in the rat's liver, lung, spleen, and kidney after a single i.v. injection (0.7 mg/kg) at different time intervals. PEG-AuNPs had a relatively long blood circulation time and accumulated primarily in the liver and spleen, where they remained for up to 28 days after administration. Increased cytoplasmic vacuolation in hepatocytes 24 h and 7 days after PEG-AuNPs exposure and apoptotic-like cells in white splenic pulp 24 h after administration has been detected, however, 28 days post-exposure were no longer observed. In contrast, at this time point, we identified significant changes in lipid metabolism, altered levels of liver injury markers, and elevated monocyte count, but without marked biological relevance. In blood cells, no DNA damage was present in any of the studied time intervals, with the exception of DNA breakage transiently detected in primary kidney cells 4 h post-injection. Our results indicate that the tissue accumulation of PEG-AuNPs might result in late toxic effects. ; This paper is supported by European Union's Horizon 2020 research and innovation program under grant agreement No. 857381, project VISION (Strategies to strengthen scientific excellence and innovation capacity for early diagnosis of gastrointestinal cancers), project HISENTS No. 685817, VEGA grants 2/0055/20, 2/0121/21.

Metal colloids are of great interest in the field of nanophotonics, mainly due to their morphology-dependent optical properties, but also because they are high quality building blocks for complex plasmonic architectures. Close-packed colloidal supercrystals not only serve for investigating the rich plasmonic resonances arising in strongly coupled arrangements, but also enables tailoring the optical response, on both the nano- and the macroscale. Bridging these vastly different length scales at reasonable fabrication costs has remained fundamentally challenging, but is essential for applications in sensing, photovoltaics or optoelectronics, among other fields. We present here a scalable approach to engineer plasmonic supercrystal arrays, based on the template-assisted assembly of gold nanospheres with topographically patterned polydimethylsiloxane molds. Regular square arrays of hexagonally packed supercrystals were achieved, reaching periodicities down to 400 nm and feature sizes around 200 nm, over areas up to 0.5 cm2. These two-dimensional supercrystals exhibit well-defined collective plasmon modes that can be tuned from the visible through the near-infrared by simple variation of the lattice parameter. We present electromagnetic modelling of the physical origin of the underlying hybrid modes, and demonstrate the application of superlattice arrays as surface-enhanced Raman scattering (SERS) spectroscopy substrates which can be tailored for a specific probe laser. We therefore investigated the influence of the lattice parameter, local degree of order, and cluster architecture, to identify the optimal configuration for highly efficient SERS of a non-resonant Raman probe with 785 nm excitation. ; The authors thank Dr. Guillermo González-Rubio for providing nanoparticles and assistance with the synthesis. C.H. acknowledges funding from the Alexander von Humboldt Foundation through a Feodor Lynen fellowship. Funding by the Spanish Ministerio de Economía, Industria y Competitividad (MINECO) is gratefully acknowledged (Grant SEV-2015-0496 in the framework of the Spanish Severo Ochoa Centre of Excellence program, and Grants MAT2016-79053-P and MAT2017-86659-R). A.M. is grateful to the funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 637116, ENLIGHTMENT). ; Peer reviewed

Recent advances in the synthesis of metal nanoparticles (MeNPs), and more specifically gold nanoparticles (AuNPs), have led to tremendous expansion of their potential applications in different fields, ranging from healthcare research to microelectronics and food packaging. The properties of functionalised MeNPs can be fine-tuned depending on their final application, and subsequently, these properties can strongly modulate their biological effects. In this review, we will firstly focus on the impact of MeNP characteristics (particularly of gold nanoparticles, AuNPs) such as shape, size, and aggregation on their biological activities. Moreover, we will detail different in vitro and in vivo assays to be performed when cytotoxicity and biocompatibility must be assessed. Due to the complex nature of nanomaterials, conflicting studies have led to different views on their safety, and it is clear that the definition of a standard biosafety label for AuNPs is difficult. In fact, AuNPs' biocompatibility is strongly affected by the nanoparticles' intrinsic characteristics, biological target, and methodology employed to evaluate their toxicity. In the last part of this review, the current legislation and requirements established by regulatory authorities, defining the main guidelines and standards to characterise new nanomaterials, will also be discussed, as this aspect has not been reviewed recently. It is clear that the lack of well-established safety regulations based on reliable, robust, and universal methodologies has hampered the development of MeNP applications in the healthcare field. Henceforth, the international community must make an effort to adopt specific and standard protocols for characterisation of these products.

[EN] A simple and effective colorimetric method for the detection of normetanephrine (NMN), an O-methylated metabolite of norepinephrine, using functionalised gold nanoparticles is described. This metabolite is an important biomarker in the diagnosis of adrenal tumours such as pheocromocytoma or paraganglioma. The colorimetric probe consists of spherical gold nanoparticles (AuNPs) functionalised with two different ligands, which specifically recognize different functional groups in normetanephrine. Thus, a benzaldehyde-terminated ligand was used for the recognition of the amino alcohol moiety in NMN, by forming the corresponding oxazolidine. On the other hand, N-acetyl-cysteine was chosen for the recognition of the phenolic hydroxyl group through the formation of hydrogen bonds. The selective double molecular recognition between the probe and the hydroxyl and the amino-alcohol moieties of normetanephrine led to interparticle-crosslinking aggregation resulting in a change in the color of the solution, from red to blue, which could be observed by naked eye. The probe was highly selective towards normetanephrine and no color changes were observed in the presence of other neurotransmitter metabolites such as homovanillic acid (HVA) (dopamine metabolite), 5-hydroxyindoleacetic acid (5-HIAA) (serotonin metabolite), or other biomolecules present in urine such as glucose (Glc), uric acid (U.A), and urea. Finally, the probe was evaluated in synthetic urine with constituents that mimic human urine, where a limit of detection of 0.5 mu M was achieved. ; Financial support from the Spanish Government (project MAT2015-64139-C4) and Generalitat Valenciana (Project PROMETEOII/2014/047 and AICO/2017/093) is gratefully acknowledged. T. Godoy-Reyes is grateful to Generalitat Valenciana for her Santiago Grisolia fellowship. ; Godoy-Reyes, TM.; Costero, AM.; Gaviña, P.; Martínez-Máñez, R.; Sancenón Galarza, F. (2019). Colorimetric detection of normetanephrine, a pheochromocytoma biomarker, using bifunctionalised gold nanoparticles. ...

We developed a nanostructure to enhance the photoluminescence intensity of two-dimensional monolayers of transition metal dichalcogenides based on plasmonic supercrystal arrays. These plasmonic supercrystal arrays are deposited on top the monolayers by means of a template-assisted assembly of gold nanospheres with patterned polydimethylsiloxane molds [1]. These supercrystals arrays consist on square arrays of hexagonally packed gold nanoparticles (50 nm of diameter) which exhibit well-defined surface lattice resonance modes that can be tuned from the visible through the near-infrared by simple variation of the lattice parameter. This tunability can be used to enhance the photoluminescence emission of different transition metal dichalcogenides monolayers. So, as proof of concept, the photoluminescence signal of the monolayer MoS2 and MoSe2 can be significantly enhanced up to 5-6-fold coupling the frequency of the surface lattice resonance of the plasmonic supercrystal to the frequency emission of the transition metal dichalcogenides monolayer. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 840064

Positively polarized gold nanoparticles have been demonstrated for use as stable olefin carriers for facilitated olefin transport membranes. The formation and size of gold nanoparticles stabilized by 4-dimethylaminopyridine (DMAP) were monitored using X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–visible spectroscopy. Nanocomposite membranes that deliver high separation performance for olefin/paraffin mixtures were prepared by dispersing gold nanoparticles stabilized by DMAP in a polymer matrix, poly(vinyl pyrrolidone) (PVP). X-ray photoelectron spectroscopy (XPS) and zeta potential measurements revealed that gold nanoparticles stabilized by DMAP exhibited a high positive polarity, which is responsible for the reversible interaction between the gold nanoparticles and olefin molecules. Compared to neat PVP membranes, the composite membranes consisting of PVP and the polarized gold nanoparticles showed stable and enhanced separation of olefin/paraffin mixtures. ; This work was supported by Energy Technology R&D program (2006-E-ID11-P-13) under the Korea Ministry of Commerce, Industry and Energy (MOCIE). KC acknowledges the financial support of NSI-NCRC and the Ministry of Education through the Brain Korea 21 Program at Seoul National University. This work was also supported by ERC Program of KOSEF grant funded by the Korea government(MEST) (R11-2005-048-00000-0).