Polymer micro and nanoparticles containing B(III) compounds as emissive soft materials for cargo encapsulation and temperature-dependent applications

Polymer nanoparticles doped with fluorescent molecules are widely applied for biological assays, local temperature measurements, and other bioimaging applications, overcoming several critical drawbacks, such as dye toxicity, increased water solubility, and allowing imaging of dyes/drug delivery in water. In this work, some polymethylmethacrylate (PMMA), polyvinylpyrrolidone (PVP) and poly(styrene-butadiene-styrene) (SBS) based micro and nanoparticles with an average size of about 200 nm and encapsulating B(III) compounds have been prepared via the reprecipitation method by using tetrahydrofuran as the oil phase and water. The compounds are highly hydrophobic, but their encapsulation into a polymer matrix allows obtaining stable colloidal dispersions in water (3.39 µM) that maintain the photophysical behavior of these dyes. Although thermally activated non-radiative processes occur by increasing temperature from 25 to 80◦C, the colloidal suspension of the B(III) particles continues to emit greenish light (λ = 509 nm) at high temperatures. When samples are cooling back to room temperature, the emission is restored, being reversible. A probe of concept drug delivery study was conducted using coumarin 6 as a prototype of a hydrophobic drug.publishersversionpublishe

Synthesis, Structural Analysis, and Peroxidase-Mimicking Activity of AuPt Branched Nanoparticles

Funding Information: This work received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia, and Ministério da Ciência, Tecnologia e Ensino Superior) through the projects Met4Cat, EXPL/QUI-COL/0263/2021 DOI: 10.54499/EXPL/QUI-COL/0263/2021; UIDP/50006/2020 DOI: 10.54499/UIDP/50006/2020; and UIDB/50006/2020 DOI: 10.54499/UIDB/50006/2020. The authors thank the Spanish National Research Council (CSIC) (project 202480E088) for their support. Publisher Copyright: © 2024 by the authors.Bimetallic nanomaterials have generated significant interest across diverse scientific disciplines, due to their unique and tunable properties arising from the synergistic combination of two distinct metallic elements. This study presents a novel approach for synthesizing branched gold–platinum nanoparticles by utilizing poly(allylamine hydrochloride) (PAH)-stabilized branched gold nanoparticles, with a localized surface plasmon resonance (LSPR) response of around 1000 nm, as a template for platinum deposition. This approach allows precise control over nanoparticle size, the LSPR band, and the branching degree at an ambient temperature, without the need for high temperatures or organic solvents. The resulting AuPt branched nanoparticles not only demonstrate optical activity but also enhanced catalytic properties. To evaluate their catalytic potential, we compared the enzymatic capabilities of gold and gold–platinum nanoparticles by examining their peroxidase-like activity in the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB). Our findings revealed that the incorporation of platinum onto the gold surface substantially enhanced the catalytic efficiency, highlighting the potential of these bimetallic nanoparticles in catalytic applications.publishersversionpublishe

the role of adenosine monophosphate

Funding Information: The authors acknowledge financial support from the European Innovation Council (Horizon 2020 Project: 965018—BIOCELLPHE), the MCIN/AEI/10.13039/501100011033 (grant PID2019-108954RB-I00), the FSE (“El FSE invierte en tu futuro”), the Xunta de Galicia/FEDER (grant GRC ED431C 2020/09), the European Regional Development Fund (ERDF), and the Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior, FCT-MCTES (grants UIDB/50006/2020, UIDP/50006/2020 and Met4cat, EXPL/QUI-COL/0263/2021). J. F.-L. thanks FCT-UNL for the research contract through the Program DL 57/2016−Norma Transitória. S. N. thanks the FCT-MCTES Portugal for her doctoral grant associated with the Chemistry PhD program (SFRH/BD/144618/2019). C. F.-L. acknowledges Xunta de Galicia for a predoctoral scholarship (Programa de axudas á etapa predoutoral). C. L., A. F. L., S. N and J. F. L thank the financial support of the PROTEOMASS Scientific Society (Portugal) (General Funding Grants 2022-2023) and the Associate Laboratory Research Unit for Green Chemistry-Clean Processes and Technologies - LAQV/REQUIMTE. This work was carried out in part through the use of the INL Advanced Electron Microscopy, Imaging and Spectroscopy Facility and Microscopy Facility at CACTI (Universidade de Vigo). The authors thank Dr. Jamila Djafari for her assistance with the graphical abstract. Publisher Copyright: © 2023 The Royal Society of Chemistry.The seed-mediated growth of gold nanostructures is known to be strongly dependent not only on the gold seed nanocrystal structure but also on the presence of different additives that may influence the morphology, and therefore the crystalline structure of the final nanoparticle. Among the different additives or capping ligands, biomolecules are an interesting family due to their potential biomedical applications such as drug delivery, bioimaging, biosensing, phototherapy, and antimicrobial activities. Here, we develop a seed-mediated strategy for synthesizing uniform Au nanostars with tuneable optical properties which involves adenosine monophosphate (AMP) as a capping ligand. The experimental data reveal the key role of AMP not just providing colloidal stability and directing the reduction of the gold precursor via complexation but also mediating the anisotropic growth of the Au seeds via its selective adsorption on the different crystalline facets of Au nanoparticles. These observations agree with theoretical simulations carried out using molecular dynamics and density functional theory (DFT) calculations. Interestingly, the obtained Au nanostars showed high thermal stability as well as colloidal stability in polar organic solvents, which allowed their direct silica coating via the Stöber method. Importantly, we also explored the mimic enzymatic activity of the resulting gold nanostars and observed a superior catalytic activity compared with other gold nanoparticles reported in the literature.publishersversionpublishe

Copper(i) as a reducing agent for the synthesis of bimetallic PtCu catalytic nanoparticles

Funding Information: This work received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the projects UIDB/50006/2020 and UIDP/50006/2020. S. N., C. L., J. L. C., A. F. L., and J. F. L. are thankful for the financial support from national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through project Met4Cat, EXPL/QUI-COL/0263/2021. This work was supported by the Spanish Government and the Spanish National Research Council (CSIC) (project PIE 201980E081). We thank the financial support by the PROTEOMASS Scientific Society (Portugal) (General Funding Grant 2022). S. N. thanks FCT/MCTEC (Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) Portugal for her doctoral grant associated with the Chemistry PhD program (SFRH/ BD/144618/2019). J. F. L. thanks FCT for the research contract through the Program DL 57/2016–Norma Transitória. A. F. L., J. F. L., S. N., J. L. C., and C. L. thank FCT/MCTES (Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) for the national funds received through the project SiSi4Bacter PTDC/QUI-COL/1517/2020. This work was carried out in part through the use of the INL user facilities. The authors thank Dr Jamila Djafari for the conceptualization and design of the graphical abstract. We also thank Ramiro Martínez from Novozymes for the gift of enzymes. Funding Information: This work received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the projects UIDB/50006/2020 and UIDP/50006/2020. S. N., C. L., J. L. C., A. F. L., and J. F. L. are thankful for the financial support from national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through project Met4Cat, EXPL/QUI-COL/0263/2021. This work was supported by the Spanish Government and the Spanish National Research Council (CSIC) (project PIE 201980E081). We thank the financial support by the PROTEOMASS Scientific Society (Portugal) (General Funding Grant 2022). S. N. thanks FCT/MCTEC (Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) Portugal for her doctoral grant associated with the Chemistry PhD program (SFRH/ BD/144618/2019). J. F. L. thanks FCT for the research contract through the Program DL 57/2016-Norma Transitória. A. F. L., J. F. L., S. N., J. L. C., and C. L. thank FCT/MCTES (Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) for the national funds received through the project SiSi4Bacter PTDC/QUI-COL/1517/2020. This work was carried out in part through the use of the INL user facilities. The authors thank Dr Jamila Djafari for the conceptualization and design of the graphical abstract. We also thank Ramiro Martínez from Novozymes for the gift of enzymes. Publisher Copyright: © 2023 RSCThis work investigates the potential utilization of Cu(i) as a reducing agent for the transformation of the platinum salt K2PtCl4, resulting in the production of stable nanoparticles. The synthesized nanoparticles exhibit a bimetallic composition, incorporating copper within their final structure. This approach offers a convenient and accessible methodology for the production of bimetallic nanostructures. The catalytic properties of these novel nanomaterials have been explored in various applications, including their use as artificial metalloenzymes and in the degradation of dyes. The findings underscore the significant potential of Cu(i)-mediated reduction in the development of functional nanomaterials with diverse catalytic applications.publishersversionepub_ahead_of_prin

Synthesis and Structural Characterization of Branched Bimetallic AuPd Nanoparticles with a Highly Tunable Optical Response

Funding Information: This work received financial support from Portugal national funds [Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior (FCT/MCTES)] through the Projects UIDB/50006/2020 and UIDP/50006/2020. Silvia Nuti, Carlos Lodeiro, José-Luis Capelo-Martinez, Adrián Fernández-Lodeiro, and Javier Fernández-Lodeiro thank the financial support from national funds (FCT/MCTES) through Project Met4Cat (EXPL/QUI-COL/0263/2021). The authors thank the financial support by the PROTEOMASS Scientific Society (Portugal) (General Funding Grant 2023). The authors acknowledge funding from the European Union’s Horizon 2020 Research and Innovation Program under Grant 823717-ESTEEM3, and Ana B. Hungría thanks the financial support from Junta de Andalucía Project P20_00968. Silvia Nuti thanks FCT/MCTEC (Portugal) for her doctoral grant associated with the chemistry Ph.D. program (SFRH/BD/144618/2019). Javier Fernández-Lodeiro thanks FCT for the research contract through the Program DL 57/2016-Norma Transitória. The work was carried out partially through the INL User Facilities (Braga, Portugal) and the Electron Microscope Division (DME) of the Servicios Centrales de Investigación Científica y Tecnológica (SC-ICYT) at Cadiz University (Cadiz, Spain). The authors thank Dr. Jamila Djafari for the assistance with the design of the graphical abstract. Funding Information: This work received financial support from Portugal national funds [Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior (FCT/MCTES)] through the Projects UIDB/50006/2020 and UIDP/50006/2020. Silvia Nuti, Carlos Lodeiro, José-Luis Capelo-Martinez, Adrián Fernández-Lodeiro, and Javier Fernández-Lodeiro thank the financial support from national funds (FCT/MCTES) through Project Met4Cat (EXPL/QUI-COL/0263/2021). The authors thank the financial support by the PROTEOMASS Scientific Society (Portugal) (General Funding Grant 2023). The authors acknowledge funding from the European Union’s Horizon 2020 Research and Innovation Program under Grant 823717-ESTEEM3, and Ana B. Hungría thanks the financial support from Junta de Andalucía Project P20_00968. Silvia Nuti thanks FCT/MCTEC (Portugal) for her doctoral grant associated with the chemistry Ph.D. program (SFRH/BD/144618/2019). Javier Fernández-Lodeiro thanks FCT for the research contract through the Program DL 57/2016–Norma Transitória. The work was carried out partially through the INL User Facilities (Braga, Portugal) and the Electron Microscope Division (DME) of the Servicios Centrales de Investigación Científica y Tecnológica (SC-ICYT) at Cadiz University (Cadiz, Spain). The authors thank Dr. Jamila Djafari for the assistance with the design of the graphical abstract. Publisher Copyright: © 2023 The Authors. Published by American Chemical Society.Bimetallic nanostructures composed of gold (Au) and palladium (Pd) have garnered increased interest for their applications in heterogeneous catalysis. This study reports a simple strategy for manufacturing Au@Pd bimetallic branched nanoparticles (NPs), which offer a tunable optical response, using polyallylamine-stabilized branched AuNPs as template cores for Pd overgrowth. The palladium content can be altered by manipulating the concentration of PdCl42- and ascorbic acid (AA) that are injected, which permit an overgrowth of the Pd shell up to ca. 2 nm thick. The homogeneous distribution of Pd at the surfaces of Au NPs can be carried out regardless of their size or branching degree, which allows for an adjustment of the plasmon response in the near-infrared (NIR) spectral range. As a proof of concept, the nanoenzymatic activity of pure gold and gold-palladium NPs was compared, exploring their peroxidase-like activity in the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB). The bimetallic AuPd NPs demonstrate an increase in the catalytic properties attributed to the presence of palladium at the surface of gold.publishersversionpublishe

Synthesis of tuneable gold nanostars: the role of adenosine monophosphate

The seed-mediated growth of gold nanostructures is known to be strongly dependent not only on the gold seed nanocrystal structure but also on the presence of different additives that may influence the morphology, and therefore the crystalline structure of the final nanoparticle. Among the different additives or capping ligands, biomolecules are an interesting family due to their potential biomedical applications such as drug delivery, bioimaging, biosensing, phototherapy, and antimicrobial activities. Here, we develop a seed-mediated strategy for synthesizing uniform Au nanostars with tuneable optical properties which involves adenosine monophosphate (AMP) as a capping ligand. The experimental data reveal the key role of AMP not just providing colloidal stability and directing the reduction of the gold precursor via complexation but also mediating the anisotropic growth of the Au seeds via its selective adsorption on the different crystalline facets of Au nanoparticles. These observations agree with theoretical simulations carried out using molecular dynamics and density functional theory (DFT) calculations. Interestingly, the obtained Au nanostars showed high thermal stability as well as colloidal stability in polar organic solvents, which allowed their direct silica coating via the Stöber method. Importantly, we also explored the mimic enzymatic activity of the resulting gold nanostars and observed a superior catalytic activity compared with other gold nanoparticles reported in the literature.Agencia Estatal de Investigación | Ref. PID2019-108954RB-I00Xunta de Galicia | Ref. ED431C 2020/09Fundação para a Ciência e a Tecnologia | Ref. UIDB/50006/2020Fundação para a Ciência e a Tecnologia | Ref. UIDP/50006/2020Fundação para a Ciência e a Tecnologia | Ref. EXPL/QUI-COL/0263/2021Universidade de Vigo/CISU

Synthesis of mesoporous silica coated gold nanorods loaded with methylene blue and its potentials in antibacterial applications

Funding Information: Funding: We thank the financial support by the PROTEOMASS Scientific Society (Portugal) (General Funding Grant 2019–2020), as well as the Associate Laboratory Research Unit for Green Chemistry— Clean Processes and Technologies—LAQV-REQUIMTE financed by national funds from FCT/MEC (UIDB/04077/2020) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER—007265). J.D.; A.F.-L.; C.L.; J.F.-L. and J.L.C.-M. thanks to the FCT-MEC the research grant SiSi4Bacter (PTDC/QUI-COL/1517/2020). J.F.-L. thank FCT/MEC (Portugal) the junior researcher contract under DL57 pro-gramme. J.D. thanks the Project PTDC/QEQ-MED/2118/2014 for her researcher contract. A.F.-L. thanks the FCT-MEC Portugal for his doctoral grant associated with the Green Chemistry PhD. Program (SFRH/BD/52528/2014) and the PROTEOMASS Scientific Society Postdoctoral grant during August 2019–March 2021. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.In this work, the successful preparation and characterization of gold nanorods (AuNRs) coated with a mesoporous silica shell (AuNRs@Simes) was achieved. Conjugation with methylene blue (MB) as a model drug using ultrasound-stimulated loading has been explored for further application in light-mediated antibacterial studies. Lyophilization of this conjugated nanosystem was analyzed using trehalose (TRH) as a cryogenic protector. The obtained stable dry formulation shows potent antimicrobial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria after a simple post-treatment irradiation method with a red laser during a short time period.publishersversionpublishe

Tailoring Mesoporous Silica-Coated Silver Nanoparticles and Polyurethane-Doped Films for Enhanced Antimicrobial Applications

This work was supported by the Associate Laboratory for Green Chemistry—LAQV which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020) as well as the Scientific Society PROTEOMASS (Portugal) for funding support (General Funding Grant). This work was also supported by the Mechanical Engineering and Resource Sustainability Center- MEtRICs which is funded by national funds from FCT/MCTES (https://doi.org/10.54499/UIDB/04077/2020, (28 February 2024), https://doi.org/10.54499/UIDP/04077/2020 (28 February 2024)). S.N., J.F.-L., A.F.-L., E.O., J.L.C-M. and C.L. thank the FCT-MEC for the research grant SiSi4Bacter (PTDC/QUI-COL/1517/2020). E.O. thanks FCT/MEC (Portugal) for the individual contract, CEECIND/05280/2022. S.N. and J.G. thank the FCT/MCTES (Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) for their doctoral grants associated with the Chemistry PhD program (SFRH/BD/144618/2019) and (2022.09495.BD). A.F.L. thanks the FCT/MCTES (Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) for his research contract through the project PTDC/QUI-COL/1517/2020. J.F-.L. thanks the FC/MEC (Portugal) for the individual research contract DL57/2016 Norma Transitoria. The work was carried out partially through the INL User Facilities (Braga, Portugal). Publisher Copyright: © 2024 by the authors.The global increase in multidrug-resistant bacteria poses a challenge to public health and requires the development of new antibacterial materials. In this study, we examined the bactericidal properties of mesoporous silica-coated silver nanoparticles, varying the core sizes (ca. 28 nm and 51 nm). We also investigated gold nanoparticles (ca. 26 nm) coated with mesoporous silica as possible inert metal cores. To investigate the modification of antimicrobial activity after the surface charge change, we used silver nanoparticles with a silver core of 28 nm coated with a mesoporous shell (ca. 16 nm) and functionalized with a terminal amine group. Furthermore, we developed a facile method to create mesoporous silica-coated silver nanoparticles (Ag@mSiO2) doped films using polyurethane (IROGRAN®) as a polymer matrix via solution casting. The antibacterial effects of silver nanoparticles with different core sizes were analyzed against Gram-negative and Gram-positive bacteria relevant to the healthcare and food industry. The results demonstrated that gold nanoparticles were inert, while silver nanoparticles exhibited antibacterial effects against Gram-negative (Escherichia coli and Salmonella enterica subsp. enterica serovar Choleraesuis) and Gram-positive (Bacillus cereus) strains. In particular, the larger Ag@mSiO2 nanoparticles showed a minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of 18 µg/mL in the Salmonella strain. Furthermore, upon terminal amine functionalization, reversing the surface charge to positive values, there was a significant increase in the antibacterial activity of the NPs compared to their negative counterparts. Finally, the antimicrobial properties of the nanoparticle-doped polyurethane films revealed a substantial improvement in antibacterial efficacy. This study provides valuable information on the potential of mesoporous silica-coated silver nanoparticles and their applications in fighting multidrug-resistant bacteria, especially in the healthcare and food industries.publishersversionpublishe

Exploring the Control in Antibacterial Activity of Silver Triangular Nanoplates by Surface Coating Modulation

In the present work, the synthesis and characterization of silver triangular nanoplates (AgNTs) and their silica coating composites are reported. Engineering control on the surface coating has demonstrated the possibility to modulate the antibacterial effect. Several AgNT-coated nanomaterials, such as PVP (Polyvinylpyrrolidone) and MHA (16-mercaptohexadecanoic acid) as a stable organic coating system as well as uniform silica coating (≈5 nm) of AgNTs, have been prepared and fully characterized. The antibacterial properties of the systems reported, organic (MHA) and inorganic (amine and carboxylic terminated SiO2) coating nanocomposites, have been tested on Gram-positive and Gram-negative bacteria strains. We observed that the AgNTs' organic coating improved antimicrobial properties when compared to other spherical silver colloids found in the literature. We have also found that thick inorganic silica coating decreases the antimicrobial effect, but does not cancel it. In addition, the effect of surface charge in AgNTs@Si seems to play a crucial role toward S. aureus ATCC 25923 bacteria, obtaining MIC/MBC values compared to the AgNTs with an organic coating

Pollutant metal ions detection and preparation of water-soluble fluorescent polymeric particles

Funding Information: G.D. thanks to the European Regional Development Fund within the Operational Programme Science and Education for Smart Growth 2014–2020 under the Project Center of Exellence: National center of mechatronics and clean technologies - BG05M2OP001-1.001-0008 for the financial support. Funding Information: This work was supported by the Associate Laboratory for Green Chemistry - LAQV which is financed by national funds from FCT/MCTES ( UIDB/50006/2020 and UIDP/50006/2020 ) as well as the PROTEOMASS Scientific Society (Portugal) for funding support (General Funding Grant 2022–2023). F.D. thanks to FCT / MEC (Portugal) for his doctoral grant 2021.05161.BD . E.O thanks FCT / MEC (Portugal) for the individual contract, CEECIND/00648/2017. J.F-.L. thanks the FCT / MEC (Portugal) for the individual research contract DL57. HMS acknowledges the Associate Laboratory for Green Chemistry-LAQV ( LA/P/0008/2020 ) funded by FCT / MCTES for his research contract. Funding Information: The financial support by the Bulgarian National Science Fund (BNSF) under grant – “Novel styryl and polymethine fluorophores as potential theranostic agents “contract N◦ КП-06-М59/1 from 15.11.2021 is gratefully acknowledged by A.K. This work is also developed and acknowledged by A.K. as part of contract №: BG-RRP-2.004-0002-C01, Laboratory of Organic Functional Materials (Project BiOrgaMCT), Procedure BG-RRP-2.004, Establishing of a network of research higher education institutions in Bulgaria”, funded by BULGARIAN NATIONAL RECOVERY AND RESILIENCE PLAN ”. Publisher Copyright: © 2023 The AuthorsPolarity-sensitive dansyl derivatives L1 and L2 were synthesized and their ability to sense pollutant metal ions was investigated. All compounds were found to be highly sensitive towards Cu2+ and Hg2+ metal ions, while L2 being able to detect and quantify Hg2+ concentrations as low as 2.5 μM. Both L1 and L2 exhibit positive solvatofluorochromic behaviour, modulated in the presence of water, which in turn results in fluorescence enhancement via aggregation-induced emission (AIE). Seeking stability and water solubility, luminescent L1-based polystyrene-block-polybutadiene-block-polystyrene (SBS) microparticles (size: 520 ± 76 nm) were successfully prepared while maintaining the fluorescence emission of fluorophore L1 (φ = 22%). This work exemplifies the multiple properties of dansyl-derivatives and their promising applications in biomedicine and environmental fields.publishersversionpublishe