Nanoestructures metal·lobiomoleculars

La miniaturització de materials metal·lorgànics a escala nanomètrica és una estratègia emergent per al desenvolupament de noves nanoestructures d'una gran diversitat composicional, estructural i morfològica. Aquests nous nanomaterials, molts d'ells porosos, poden presentar un ventall variat de propietats i, en conseqüència, poden ser utilitzats en diverses àrees tecnològiques, sigui en l'emmagatzematge o la separació de gasos i catàlisis, sigui per formar nous sensors, nanotransportadors de fàrmacs i agents de contrast. Immersos en el desenvolupament d'aquestes nanoestructures, el nostre grup de recerca està actualment desenvolupant una nova aproximació basada en l'ús de biomolècules com a lligands orgànics que, coordinades amb ions metàl·lics, permetin la creació de nanoarquitectures metal·lobiomoleculars. Aquestes nanoestructures combinaran les propietats dels nanomaterials metal·lorgànics (per exemple, la porositat) amb les propietats intrínseques de les biomolècules, com ara la biocompatibilitat, el reconeixement selectiu o la quiralitat. En aquesta comunicació s'exposaran els últims avanços efectuats en el desenvolupament de noves metodologies sintètiques i el seu ús per sintetitzar les primeres nanoestructures metal·lobiomoleculars formades per aminoàcids com l'àcid aspàrtic (Asp) i la cisteïna (Cys).The miniaturization of metal-organic materials to the nanoscale is an emerging strategy for the development of new nanostructures with tailored compositions, structures and morphologies. These new nanomaterials, many of which are porous, may have a wide range of properties and consequently show promise for many practical applications, such as gas storage or separation, catalysis, sensors, drug-delivery and contrast agents. With this aim, our research group is currently developing a new approach using biomolecules to coordinate metal ions and create metal-biomolecule nanoarchitectures. These new bioinspired nanostructures will combine the properties of more conventional metal-organic nanomaterials (e. g. porosity) with the intrinsic characteristics of the biomolecules, such as biocompatibility, chirality and selective recognition capabilities. This paper presents the latest advances in the development of new synthesis methodologies and their use in producing the first metal-biomolecule nanostructures based on amino acids, such as aspartic acid (Asp) and cysteine (Cys)

Functional supramolecular tetrathiafulvalene-based films with mixed valences states

Tetrathiafulvalene molecules substituted with a carboxylic acid group (TTFCOOH) were bound as redox-active moieties into a poly(4-vinyl pyridine) (P4VP) skeleton through non-covalent interactions (hydrogen bonds). The aspect of the resulting P4VP-TTFCOOH films showed a uniform and smooth morphology. Moreover, the redox function of TTFCOOH in P4VP-TTFCOOH was demonstrated using tetrachloroauric acid, iron(III) perchlorate and iodine vapors as doping agents. The oxidized states of TTFCOOH as well as the mixed valance state TTFCOOH0-TTFCOOH+• were generated in a controlled manner in solid state, resulting in an organic film capable of charge transport. The charge transport along the organic donor molecules hydrogen bonded to the polymer matrix was demonstrated employing Electrostatic Force Microscopy (EFM)Postprint (author's final draft

Towards nanowire sensors on a microfluidic platform: In-situ formation, positioning and sizing of nanowire bundles

Funding from the European Research Council under the 7th Framework Programme (ERC Strating Grant no. 203428 nµLIPIDS) is gratefully acknowledgedPeer Reviewe

Laser-induced chemical transformation of graphene oxide-iron oxide nanoparticles composites deposited on polymer substrates

© 2015 Elsevier Ltd. All rights reserved. Ultraviolet laser irradiation of films composed of graphene oxide (GO) and GO-magnetite (Fe3O4) nanoparticles deposited on polydimethylsiloxane substrates is carried out. The irradiations are performed in vacuum and ammonia-rich gas environments. Electron and scanning probe microscopies reveal a rippling process in GO sheets as the accumulation of laser pulses proceeds, being the effect more pronounced with the increase of laser fluence. X-ray photoelectron spectroscopy analyses point to laser-induced chemical reaction pathways in GO completely different depending on the environment and the presence or absence of Fe3O4 nanoparticles. It is demonstrated that GO-based films with diverse type of oxygen- and nitrogen-containing chemical groups can be obtained by means of laser irradiation processes. The sheet resistance of these materials is also correlated to their structure and composition.The authors acknowledge the financial support of the Spanish Ministry of Economy and Competitiveness under the project ENE2014-56109-C3-3-R, in addition to the Executive Unit for Financing Higher Education, Research, Development, and Innovation of the Romanian Ministry of Education, Research, Youth, and Sports under the Grant PN-II-PT-PCCA-2011-3.2-1235. This work was also performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract DE-AC52-06NA25396. Wei Gao thanks the start-up funding support from the College of Textiles at North Carolina State University. Josep Puigmarti Luis also acknowledge the Ramon y Cajal program (RYC-2011-08071) from the Spanish Ministry of Economy and Competitiveness.Peer Reviewe

Piezoelectric Nanomaterials Activated by Ultrasound: The Pathway from Discovery to Future Clinical Adoption

Electrical stimulation has shown great promise in biomedical applications, such as regenerative medicine, neuromodulation, and cancer treatment. Yet, the use of electrical end effectors such as electrodes requires connectors and batteries, which dramatically hamper the translation of electrical stimulation technologies in several scenarios. Piezoelectric nanomaterials can overcome the limitations of current electrical stimulation procedures as they can be wirelessly activated by external energy sources such as ultrasound. Wireless electrical stimulation mediated by piezoelectric nanoarchitectures constitutes an innovative paradigm enabling the induction of electrical cues within the body in a localized, wireless, and minimally invasive fashion. In this review, we highlight the fundamental mechanisms of acoustically mediated piezoelectric stimulation and its applications in the biomedical area. Yet, the adoption of this technology in a clinical practice is in its infancy, as several open issues, such as piezoelectric properties measurement, control of the ultrasound dose in vitro, modeling and measurement of the piezo effects, knowledge on the triggered bioeffects, therapy targeting, biocompatibility studies, and control of the ultrasound dose delivered in vivo, must be addressed. This article explores the current open challenges in piezoelectric stimulation and proposes strategies that may guide future research efforts in this field toward the translation of this technology to the clinical scene

Strain sensitive flexible magnetoelectric ceramic nanocomposites

Advanced flexible electronics and soft robotics require the development and implementation of flexible functional materials. Magnetoelectric (ME) oxide materials can convert magnetic input into electric output and vice versa, making them excellent candidates for advanced sensing, actuating, data storage, and communication. However, their application has been limited to rigid devices due to their brittle nature. Here, we report flexible ME oxide composite (BaTiO3/CoFe2O4) thin film nanostructures that can be transferred onto a stretchable substrate such as polydimethylsiloxane (PDMS). In contrast to rigid bulk counterparts, these ceramic nanostructures display a flexible behavior and exhibit reversibly tunable ME coupling via mechanical stretching. We believe our study can open up new avenues for integrating ceramic ME composites into flexible electronics and soft robotic devices

Crystalline fibres of a covalent organic framework through bottom-up microfluidic synthesis

A microfluidic chip has been used to prepare fibres of a porous polymer with high structural order, setting a precedent for the generation of a wide variety of materials using this reagent mixing approach that provides unique materials not accessible easily through bulk processes. The reaction between 1,3,5-tris(4-aminophenyl)benzene and 1,3,5-benzenetricarbaldehyde in acetic acid under continuous microfluidic flow conditions leads to the formation of a highly crystalline and porous covalent organic framework (hereafter denoted as MF-COF-1), consisting of fibrillar micro-structures, which have mechanical stability that allows for direct drawing of objects on a surfaceFinancial support from Spanish Government (Projects MAT2013-46753-C2-1-P and CTQ2014-53486-R) and FEDER are acknowledged. A. A. and J. P. L. would like to thank the financial support from the Swiss National Science Foundation (SNSF) through the project no. 200021_16017

Electrostatic Catalysis of a Click Reaction in a Microfluidic Cell

Electric fields have been highlighted as a smart reagent in nature's enzymatic machinery, as they can directly trigger or accelerate redox and/or non-redox chemical processes with stereo- and regio-specificity. In natural catalysis, controlled mass transport of chemical species in confined spaces is also key in facilitating the transport of reactants into the active reaction site. Despite the opportunities the above offers in developing strategies for a new, clean electrostatic catalysis exploiting oriented electric fields, research in this area has been mostly limited to theoretical and experimental studies at the level of single molecules or small molecular ensembles, where both the control over mass transport and scalability cannot be tested. Here, we quantify the electrostatic catalysis of a prototypical Huisgen cycloaddition in a large-area electrode surface and directly compare its performance to the traditional Cu(I)-catalyzed method of the same reaction. Mass diffusion control is achieved in a custom-built microfluidic cell, which enhances reagent transport towards the electrified reactive interface while avoiding both turbulent flow conditions and poor control of the convective mass transport. This unprecedented electrostatic continuous-flow microfluidic reactor is an example of an electric-field driven platform where clean large-scale electrostatic catalytic processes can be efficiently implemented and regulated.Comment: Main Manuscript part includes 12 pages, 4 figures, 1 table and Supporting Information part includes 20 pages, 8 figures, 1 tabl

3D printing of covalent organic frameworks: a microfluidic-based system to manufacture binder-free macroscopic monoliths

Covalent organic frameworks (COFs) have witnessed outstanding developments in the past 15 years, particularly in optimizing their pore structures, linkages, and variety of monomers used in their synthesis. Yet, a significant challenge remains unaddressed: the processability of COFs into macroscopic architectures with arbitrary shapes, as they are typically obtained as unprocessable powders. This study presents a novel strategy to address this issue by developing a 3D printable ink comprising a colloidal water suspension of COF nanoparticles. A microfluidic device is engineered that provides precise control over the gelation process of the COF-based ink, allowing for a layer-by-layer fabrication. As a result, the direct production of large-scale binder-free COF architectures from digital designs is achieved at room temperature and atmospheric pressure while eliminating the use of toxic organic solventsThis work had been supported by the Spanish MINECO (PID2019- 106268GB-C32, PID2022-138908NB-C31, TED2021-129886B-C42, PDC2022-133498-I00, and PID2020-116612RB-C33). The authors acknowledge the service from the MiNa Laboratory at IMN and funding from CM (project S2018/NMT-4291 TEC2SPACE), MINECO (project CSIC13-4E-1794) and EU (FEDER, FSE). F.Z. acknowledges financial support from the Spanish Ministry of Science and Innovation, through the “María de Maeztu” Programme for Units of Excellence in R&D (CEX2018- 000805-M). S.P., J.P.-L., and F. Z. also acknowledge support from the European Innovation Council under grant Agreement 101047081 (EVA). The authors acknowledge the support from the “(MAD2D-CM)-UAM” project funded by Comunidad de Madrid, by the Recovery, Transformation and Resilience Plan, and by NextGenerationEU from the European Unio

Exploiting Reaction-Diffusion Conditions to Trigger Pathway Complexity in the Growth of a MOF

Coordination polymers (CPs), including metal-organic frameworks (MOFs), are crystalline materials with promising applications in electronics, magnetism, catalysis, and gas storage/separation. However, the mechanisms and pathways underlying their formation remain largely undisclosed. Herein, we demonstrate that diffusion-controlled mixing of reagents at the very early stages of the crystallization process (i.e., within ≈40 ms), achieved by using continuous-flow microfluidic devices, can be used to enable novel crystallization pathways of a prototypical spin-crossover MOF towards its thermodynamic product. In particular, two distinct and unprecedented nucleation-growth pathways were experimentally observed when crystallization was triggered under microfluidic mixing. Full-atom molecular dynamics simulations also confirm the occurrence of these two distinct pathways during crystal growth. In sharp contrast, a crystallization by particle attachment was observed under bulk (turbulent) mixing. These unprecedented results provide a sound basis for understanding the growth of CPs and open up new avenues for the engineering of porous materials by using out-of-equilibrium conditions