Marcelo Ceolín

• Dr.
• Senior Researcher at National Scientific and Technical Research Council

Mesoporous ceramic materials used in applications such as catalysis, filtration, or sensing, are usually hierarchically structured. Thereby, their structural hierarchy is often inherently related to the manufacturing methods and cannot be independently locally designed along all length scales. This study combines light‐based additive manufacturing...

Paper with its mechanical strength as well as due to its microfluidic properties has emerged as an interesting sustainable material for future high-tech applications. Examples include paper-based sensors and actuators, paper-based construction materials and paper-based membranes. These examples have in common that a precise control of the water dis...

Combinatorial sensing is especially important in the context of modern drug development to enable fast screening of large data sets. Mesoporous silica materials offer high surface area and a wide range of functionalization possibilities. By adding structural control, the combination of structural and functional control along all length scales opens...

We studied ionic transport properties of UiO-66 metal-organic framework-modified solid-state nanochannels (MOF@SSNs) embedded in polyethylene terephthalate (PET) membranes, focusing on the effect of calcium ions from chloride salt (CaCl2) acting...

The wettabilities of nanoscale porous surfaces play important roles in the context of molecular and fluid transport or oil–water separation. The wettability pattern along a nanopore strongly influences fluid distribution throughout the membrane. Mesoporous silica thin films with gradually adjusted wettabilities were fabricated via cocondensation. W...

This work reports the phase behavior and electro-chemical properties of liquid coacervates made of ferricyanide and poly(ethylenimine). In contrast to the typical polyanion/polycation pairs used in liquid coacervates, the ferricyanide/poly-(ethylenimine) system is highly asymmetric because poly-(ethylenimine) has approximately 170 charges per molec...

Abstract Microfluidic devices are important, e.g. in the field of point of care diagnostics. They are of special importance, if they are fabricated out of cheap and renewable materials. Tackling complex separation or sensing problems profits from modular three‐dimensional fluidic devices. Using cotton threads as renewable material allows the modula...

Mesopores, with diameters between 2 and 50 nm, not only increase the specific surface area, but also generate hierarchically porous materials with specific properties such as capillary fluid transport, ion specific pore accessibility, or size exclusion. Paper is a strongly hierarchical, porous material with specific properties, such as capillary fo...

The synthesis of one-dimensional (1D) nanostructures in polymeric matrices has become the focus of much research, as the presence of these highly anisotropic domains determines the transport behaviour and mechanical properties of the resulting nanostructured polymers. In this work, 1D PEO nanocrystals were synthesized in situ from polystyrene-b-pol...

This review shows the most common and promising strategies to generate colloidally stable silica nanoparticles (NPs) in simulated biological fluids and sheds light on the latest advances in producing degradable silica-based structures. Silica NPs can be synthesized in a wide variety of morphologies, porosity levels, and sizes. This versatility make...

We hereby report on the thermodynamic and kinetic aspects of ZIF-8 MOF synthesis when performed using methanolic solutions of precursors and 3-mercaptopropionic acid (MPA) acting as a chemical modifying agent. MPA is of great interest as it allows us to gain control over the surface chemistry, shape, and size of colloidal porous nanounits formed. I...

The ionic screening and the response of non-specific molecules are great challenges of biosensors based on field-effect transistors (FETs). In this work, we report the construction of graphene based transistors modified with mesoporous silica thin films (MTF-GFETs) and the unique (bio)sensing properties that arise from their synergy. The developed...

Amphiphilic comb polymers, like poly(maleic anhydride-alt-1-octadecene) (PMAO), are frequently used to transfer hydrophobic magnetic nanoparticles (NPs) into aqueous media. While it is accepted that the hydrophilization is based on the interdigitation of the hydrocarbon chains from the polymer and the NP capping, the factors that determine the succ...

We have explored the use of two different iron-based porous materials for arsenic uptake from neutral pH aqueous solutions. Both materials are reminiscent of a material known as MIL-100(Fe), a Metal Organic Framework (MOF) built upon the coordination of Fe(III) ions with trimesate organic linkers (benzene tricarboxylic acid). Aside from the proverb...

The photothermal response of mercaptoundecanoic acid (MUA)-coated Ag nanoparticles (Ag@MUA NPs) in both aqueous dispersions and paper substrates was determined as a function of pH when irradiated with a green laser or a blue LED source. Aqueous dispersions of Ag@MUA NPs showed an aggregation behavior by acidification that was used for the formation...

This work reports on a novel and versatile approach to control the structure of metal–organic framework (MOFs) films by using polymeric brushes as 3D primers, suitable for triggering heterogeneous MOF nucleation. As a proof‐of‐concept, this work explores the use of poly(1‐vinylimidazole) brushes primer obtained via surface‐initiated atom transfer r...

Several examples of nanosized therapeutic and imaging agents have been proposed to date, yet for most of them there is a low chance of clinical translation due to long-term in vivo retention and toxicity risks. The realization of nano-agents that can be removed from the body after use remains thus a great challenge. Here, we demonstrate that non-eq...

ZIF‐8 (based on Zn and 2‐methylimidazole) MOF film growth can be controlled by using SI‐ATRP‐synthesized polymeric brushes as 3D primers. This strategy relies on the inclusion of chemical moieties in the brush, which are compatible with MOF chemical structure. According to such criteria, Poly(1‐vinylimidazole) brushes with increasingly higher graft...

The Cover Feature shows a 2D hexagonal mesostructured electroactive film obtained through layer‐by‐layer assembly of (ferrocenylmethyl)hexadecyldimethylammonium bromide, a redox surfactant, and poly(acrylic acid). The picture also includes an experimental GISAXS pattern of the mesostructured film. By using ferrocene‐appended surfactants as structur...

Electroactive thin films are an important element in the devices devoted to energy conversion, actuators, and molecular electronics, among others. Their build‐up by the layer‐by‐layer technique is an attractive choice since a fine control over the thickness and composition can be achieved. However, most of the assemblies described in the literature...

The restricted mobility of different liquids, polar and non-polar, were studied by means of ¹H NMR diffusion and Larmor frequency dependent relaxation measurements, upon confinement in mesoporous silica with mean pore sizes ranging from 3–30 nm. The use of alkanes as a reference in the determination of the true tortuosity value was observed to be a...

Research efforts are increasingly focused on the development of portable devices for the on‐site evaluation of pesticide residues in food. In article 1900076, Jimena S. Tuninetti and co‐workers develop a chemi‐impedimetric sensor of imazalil using metal–organic frameworks (MOFs) incorporated into a conductive PEDOT composite film. The high affinity...

Due to its deleterious effects on health, development of new methods for detection and removal of pesticide residues in primary and derived agricultural products is a research topic of great importance. Among them, imazalil (IMZ) is a widely used post‐harvest fungicide with good performances in general, and is particularly applied to prevent green...

The cover photo of July 2019 issue is dedicated to the 41st anniversary of the first reported synthetic approach of dendritic hyperbranched structure. The cover photo adopted from the Valer et al., where they reported the preparation of dendritic hyperbranched copolymers based on bis(hydroxyl methyl) propionic acid polyester and studied the archite...

It has been previously reported that poly(ethylene) (PE)-based block copolymers self-assemble in certain thermosetting matrices to form a dispersion of one-dimensional (1D) nanoribbons. Such materials exhibit exceptional properties that originate from the high aspect ratio of the elongated nano-objects. However, the ability to prepare 1D assemblies...

The molecular architecture of polymers is a crucial feature in the moment of think the relationship between properties and applications. The same polymer can present important differences according to its architecture and leads to different possible applications. In this paper, we describe the well preparation of hyperbranched copolymers based on b...

Very high aspect ratio nano-objects dispersed in a polymer matrix impart a number of desired characteristics to the material, such as barrier properties to the diffusion of small molecules. Commonly, these dispersions are obtained via top-down procedures that require several time-consuming steps of purification, surface modification, and processing...

The most critical problem regarding the use of reverse micelles (RMs) in several fields is the toxicity of their partial components. In this sense, many efforts have been made to characterize non-toxic RMs formulations based on biological amphiphiles and/or different oils. In this contribution, the microstructure of biocompatible mixed RMs formulat...

Interfacial supramolecular architectures displaying mesoscale organized components are of fundamental importance for developing materials with novel or optimized properties. Nevertheless, engineering the multilayer assembly of different building blocks onto a surface and exerting control over the internal mesostructure of the resulting film is stil...

Supramolecular self-assembly is of paramount importance for the development of novel functional materials with molecular-level feature control. In particular, the interest in creating well-defined stratified multilayers through simple methods using readily available building blocks is motivated by a multitude of research activities in the field of...

Molecular design and preparation of redox active films displaying mesoscopic levels of organization represents one of the most actively pursued research areas in nanochemistry. These mesostructured materials not only are of great interest at the fundamental level because of their unique properties but they can also be employed for a wide range of a...

Vesicles are a highly attractive morphology to achieve in micellar dispersions of block copolymers (BCP) in epoxy thermosets due to the fact that small amounts can affect a large volume fraction of the matrix, a fact that is important for toughening purposes. However, generating vesicles in epoxy matrices requires operating in a narrow range of for...

A detailed understanding of the processes taking place during the in situ synthesis of metal/polymer nanocomposites is crucial in order to manipulate the shape and size of nanoparticles (NPs) with a high level of control. In this contribution, we report an in-depth time resolved analysis of the particle formation process in silver/epoxy nanocomposi...

Polymerization-induced nanostructuration combined with crystallization-driven self-assembly was used to generate complex nanostructures in an epoxy network. A PE-b-PEO block copolymer (Mn = 1400; 50 wt % PEO), was dispersed in diglycidylether of bisphenol A (DGEBA) and homopolymerization initiated by a tertiary amine was carried out at 120 ºC (abov...

In this work the effect of the self-assembly solvent on the structure and electrochemical behavior of redox-active polyelectrolyte-surfactant complexes cast on electrode supports from aqueous and DMF solutions are presented. The complex studied is formed by complexation of osmium complex-modified polyallylamine (OsPA) with dodecylsulfate (DS) surfa...

Self-organized metallo-supramolecular heterostructures have potential applications that include molecular electronics, photovoltaics, and magnetic devices, among other examples. The main challenge that scientists typically face when designing advanced supramolecular materials is to achieve structurally defined assemblies by resolving conflicting de...

Abstract The supramacromolecular structure of core-shell amphiphilic macromolecules (CAMs) with Hyperbranched Polyethyleneimine (HPEI) cores and fatty acid chain shells (HPEI-Cn) for different chain lengths was investigated both, in colloidal suspension, solid phase and at the air-water interface using Small Angle X-ray Scattering (SAXS), Wide Angl...

Efficient electrical communication between redox proteins and electrodes is a critical issue in the operation and development of amperometric biosensors. The present study explores the advantages of a nanostructured redox-active polyelectrolyte–surfactant complex containing [Os(bpy)2Clpy]2+ (bpy=2,2′-bipyridine, py= pyridine) as the redox centers a...

Efficient electrical communication between redox proteins and electrodes is a critical issue in the operation and development of amperometric biosensors. The present study explores the advantages of a nanostructured redoxactive polyelectrolyte surfactant complex containing [Os(bpy)(2)Clpy](2+) (bpy=2,2'-bipyridine, py= pyridine) as the redox center...

The present study explores the development of mesostructured bioelectrochemical interfaces with accurate compositional and topological control of the supramolecular architecture through the layer-by-layer assembly of ternary systems based on poly(allylamine) containing an osmium polypyridyl complex (OsPA), an anionic surfactant, sodium dodecyl sulf...

In this work, the microenvironment of the core of different unimicelles of hyperbranched polyethyleneimine (HPEI) capped with different aliphatic chains (stearate, palmitate, and laurate) dissolved in toluene has been investigated. To achieve this goal we have used 1-methyl-8-oxyquinolinium betaine (QB) as a molecular probe due to its solvatochromi...

The aggregation behavior and morphological characteristics of amphiphilic block copolymer polybenzyl methacrylate-block-poly(dimethylamino)ethyl methacrylate (PBzMA-b-PDMAEMA) at the air-water interface were investigated through surface pressure measurements, atomic force microscopy (AFM) imaging, electrochemical measurements and X-ray reflectivity...

Although most eggs are intensely predated, the aerial egg clutches from the aquatic snail Pomacea canaliculata have only one reported predator due to unparalleled biochemical defenses. These include two storage-proteins: ovorubin that provides a conspicuous (presumably warning) coloration and has antinutritive and antidigestive properties, and PcPV...

Alignment between PcPV2-67 and the sequences of the five more related MACPF members from Figure 2. Light red box indicates MACPF signature; black box, MACPF domain. (TIF)

2-DE analysis of native (A) and dissociated (B) PcPV2. (TIF)

Pair Distance Distribution Function (PDDF) of PcPV2 obtained from SAXS data at different pH values. The PDDF is the probability of finding a given point-to-point distance within the boundaries of the molecule. The vertical lines indicate the mean Paired Distance obtained from the graphic. (TIF)

This work describes the synergistic combination of ionic self-assembly and recognition-directed assembly with the aim of creating highly functional bioelectrochemical interfaces compatible with the supramolecular design of a wide variety of biosensing platforms. A recently synthesized glycopolyelectrolyte constituted of polyallylamine bearing redox...

Silicon nanoparticles of 1−5 nm size (SiNPs) were synthesized by a bottom-up (BU) approach involving a chemical wet method. The contribution of different emitters to the overall excitation−emission matrix was analyzed on the assumption that pure substances existing in a unique form show an excitation wavelength-invariant emission spectrum. The occu...

Catanionic surfactants: The synthesis of a new surfactant ionic liquid with unique properties is described. The formation of reverse micelles in benzene and large unilamellar vesicles, formed spontaneously without the help of any mechanical of chemistry methods, in water is demonstrated by using dynamic light scattering and small-angle X-ray scatte...

Apple snail perivitellins are emerging as ecologically important reproductive proteins. To elucidate if the protective functions of the egg proteins of Pomacea canaliculata (Caenogastropoda, Ampullariidae), involved in embryo defenses, are present in other Pomacea species we studied scalarin (PsSC), the major perivitellin of Pomacea scalaris. Using...

This work explores the synergistic combination of ionic self-assembly and recognition-directed assembly for the modification of electrode surfaces with redox glycoenzymes on the basis of electroactive glycopolyelectrolyte-surfactant complexes.

Experimental evidence of magnetochiral dichroism is found in the hard X-ray absorption spectra of paramagnetic enantiopure molecules. An isotropic sample of a {Tb[Ni(pro)(2) ](6) }(3+) salt (pro = L- or D-prolinate) shows up to a 1% difference in absorbance when a magnetic field (1 T) is applied parallel or anti-parallel to the incident X-ray beam...

A light-responsive brush was obtained by surface-initiated ATRP of a methacrylate monomer containing ionizable −COOH side groups caged with the photoremovable group 4,5-dimethoxy-2-nitrobenzyl (NVOC). In the caged form, the polymer brush (PNVOCMA) is neutral and hydrophobic due to the presence of the aromatic chromophore. Upon irradiation the NVOC...

Silicon nanoparticles of 1–5 nm size (SiNPs) were synthesized by a bottom-up (BU) approach involving a chemical wet method. The contribution of different emitters to the overall excitation–emission matrix was analyzed on the assumption that pure substances existing in a unique form show an excitation wavelength-invariant emission spectrum. The occu...

Rational construction of interfaces based on multicomponent responsive systems in which molecular transport is mediated by structures of nanoscale dimensions has become a very fertile research area in biomimetic supramolecular chemistry. Herein, we describe the creation of hybrid mesostructured interfaces with reversible gate-like transport propert...

Rational construction of interfaces based on multi-component responsive systems in which molecular transport is mediated by structures of nanoscale dimensions has become a very fertile research area in biomimetic supramolecular chemistry. Herein, we describe the creation of hybrid mesostructured interfaces with reversible gate-like transport proper...

We demonstrate that "caged" macromolecular building blocks can endow mesoporous thin films with light responsiveness and lead to the creation of functional hybrid ensembles with phototriggered permselective properties.

The characterization and application of a polyelectrolyte-surfactant supramolecular assembly formed by poly(allylamine) and dodecyl sulfate (PA-DS) on a screen-printed graphite electrode for the preparation of electrochemical sensing platforms are presented. The system was characterized by X-ray reflectometry (XRR) and grazing-incidence small-angle...

We report the thermoreversible formation of superstructural assemblies of unimolecular micelles in solution displaying negative thermal expansion behaviour.

The convergence of chemistry, biology, and materials science has paved the way to the emergence of hybrid nanobuilding blocks that incorporate the highly selective recognition properties of biomolecules, with the tailorable functional capabilities of inorganic molecules. In this work, we describe for the first time the decoration of concanavalin A...

Nanoparticles of iron(II) triazole salts have been prepared from water-organic microemulsions. The mean size of the nanoparticles can be tuned down to 6 nm in diameter, with a narrow size distribution. A sharp spin transition from the low spin (LS) to the high spin (HS) state is observed above room temperature, with a 30-40-K-wide thermal hysteresi...

Programmable Velocity equipment was used to perform a Mössbauer Thermal Scans to allow a quasi-continuous temperature study of the magnetic transition between the low-spin and a high-spin configurations in [Fe(Htrz)2(trz)](BF4) system. The material was studied both in bulk as in nanoparticles sample forms.

There is little information on the egg proteins of gastropod mollusks. Here we focus on PV2, a novel neurotoxin from snail eggs, studying its size, shape, structure, and stability, using small angle X-ray scattering (SAXS), absorption and fluorescence spectroscopy, circular dichroism, electron microscopy and partial proteolysis. Results indicate th...

Bimetallic CoNi nanoparticles have been prepared within the apoferritin cavity. The protein shell controls size, prevents aggregation, and makes nanoparticles water-soluble. The CoNi series prepared in this way were structurally and magnetically characterized, the resulting magnetic properties varying accordingly with composition (Co(75)/Ni(25), Co...

Sterol carrier protein 2 (SCP2) is an intracellular protein domain found in all forms of life. It was originally identified as a sterol transfer protein, but was recently shown to also bind phospholipids, fatty acids, and fatty-acyl-CoA with high affinity. Based on studies carried out in higher eukaryotes, it is believed that SCP2 targets its ligan...

We report a biophysical characterisation of apo-sterol carrier protein-2 from Yarrowia lipolytica (YLSCP-2) and its urea-induced unfolding followed by intrinsic tryptophan fluorescence, far-UV CD, ANS binding, and small angle X-ray scattering (SAXS). The unfolding is described as a three-step process. The first steps, between 1 and 2 M urea, have w...

Perivitellins are important components of the perivitelline fluid (PVF) that surrounds gastropod embryos. The glyco-lipo-carotenoprotein ovorubin (OR) from eggs of the snail Pomacea canaliculata has been the most studied to date. Here we report the characterization of scalarin (SC), a glyco-lipo-carotenoprotein from the PVF of P. scalaris. SC was p...

Nanocrystalline metals display interesting basic and technological properties related to their chemical and structural properties. Among other properties, they display a richer phase diagram due to the additional degree of freedom introduced by the nanoparticles surface. Metal nanoparticles encapsulated within biological macromolecules have the add...

Ovorubin, a 300-kDa thermostable oligomer, is the major egg protein from the perivitellin fluid that surrounds the embryos of the apple snail Pomacea canaliculata. It plays essential roles in embryo development, including transport and protection of carotenoids, protease inhibition, photoprotection, storage, and nourishment. Here, we report ovorubi...

Transmission Electron Microscopy (TEM), X-ray Absorption Near Edge Spectroscopy (XANES), Electron Energy-Loss Spectroscopy (EELS), Small-Angle X-ray Scattering (SAXS), and SQUID magnetic studies were performed in a batch of horse spleen ferritins from which iron had been gradually removed, yielding samples containing 2200, 1200, 500, and 200 iron a...

It is well known that some of the metal ions remain bound to apoferritin when incubating apoferritin with metal ions. In this study a structural insight, from X-ray absorption spectroscopy (XAS) and small angle X-ray scattering (SAXS) experiments, into the mechanism of inorganic core formation is presented. The results indicate that, in the case of...

Ovorubin (OR) is the major perivitellin of the eggs of Pomacea canaliculata. The astaxanthin (ASX) binding and structural stability of OR were investigated by fluorescence spectroscopy and circular dichroism (CD). The apo-OR (without astaxanthin) shows a single, high affinity binding site for ASX (K(D)=0.5 microM). The quenching of tryptophan fluor...

The aggregation of alpha-synuclein (AS) is characteristic of Parkinson's disease and other neurodegenerative synucleinopathies. Interactions with metal ions affect dramatically the kinetics of fibrillation of AS in vitro and are proposed to play a potential role in vivo. We recently showed that Cu(II) binds at the N-terminus of AS with high affinit...

The signal to noise ratio in hyperfine spectra split by nuclear quadrupole interactions can be improved significantly by cross correlating experimental with theoretical spectra, especially for higher spins. In part I of the paper we present all technical details of this new approach and give examples for half integer and integer spins. In part II w...

The floating head (flh) gene in zebrafish encodes a homeodomain protein, which is essential for notochord formation along the entire body axis. flh orthologs, termed Not genes, have been isolated from chick and Xenopus, but no mammalian ortholog has yet been identified. Truncate (tc) is an autosomal recessive mutation in mouse that specifically dis...

Metallo-beta-lactamases are zinc enzymes able to hydrolyze the four-membered ring of beta-lactam antibiotics, representing one of the latest generations of beta-lactamases. These enzymes belong to the zinc metallo-hydrolase family of the beta-lactamase fold. Enzymes belonging to this family have a bimetallic active site whose structure varies among...

Solvent-induced directional aggregation of human carbonic anhydrase II (hCA) was studied by small angle X-ray scattering and fluorescence and fourth-derivative ultraviolet absorption spectroscopy. We propose that hCA at 5 mg ml(-1) in pure water forms head-to-tail oligomers built up, on average, by four to five monomers. At higher protein concentra...

The hydrodynamic behaviour of the bovine serum albumin (BSA) was studied by means of the Perturbed Angular Correlation (PAC) technique as a function of the hydrostatic pressure (up to 4.1 kbar) applied to the sample. The results have clearly shown that at moderated pressures (around 1.5 kbar) the BSA molecule suffers structural modifications which...

The hydrodynamic behaviour of the bovine serum albumin (BSA) was studied by means of the Perturbed Angular Correlation (PAC) technique as a function of the hydrostatic pressure (up to 4.1 kbar) applied to the sample. The results have clearly shown that at moderated pressures (around 1.5 kbar) the BSA molecule suffers structural modifications which...

The last three C-terminal residues (129-131) of intestinal fatty acid-binding protein (IFABP) participate in four main-chain hydrogen bonds and two electrostatic interactions to sequentially distant backbone and side-chain atoms. To assess if these interactions are involved in the final adjustment of the tertiary structure during folding, we engine...

The last three C-terminal residues (129–131) of intestinal fatty acid-binding protein (IFABP) participate in four main-chain hydrogen bonds and two electrostatic interactions to sequentially distant backbone and side-chain atoms. To assess if these interactions are involved in the final adjustment of the tertiary structure during folding, we engine...