Electrochemical nanoarchitectonics through polyaminobenzylamine-dodecyl phosphate complexes: Redox activity and mesoscopic organization in self-assembled nanofilms

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 are not only of great interest at the fundamental level because of their unique properties but they can also be employed for a wide range of applications such as electrocatalysts, electronic devices, and electrochemical energy conversion and storage. Herein, we introduce a simple and straightforward strategy to chemically modify electrode surfaces with self-assembled electroactive polyelectrolyte-surfactant complexes. These assemblies are composed of amino-appended polyaniline and monododecyl phosphate. The complexes were deposited by spin-coating and the films were characterized by spectroscopic and X-ray-based techniques: XRR, GISAXS, WAXS, and XPS. The films presented a well-defined lamellar structure, directed by the strong interaction between the phosphate groups and the positively charged amine groups in the polyelectrolyte. These films also displayed intrinsic electroactivity in both acidic and neutral solutions, showing that the polymer remains electroactive and ionic transport is still possible through the stratified and hydrophobic coatings. The stability and enhanced electroactivity in neutral solutions make these assembled films promising building blocks for the construction of nanostructured electrochemical platforms.Fil: Lorenzo, Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Marmisollé, Waldemar Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Maza, Eliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Ceolin, Marcelo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Azzaroni, Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

Electrochemical oxidation of fisetin: Studies related to its adsorption on glassy carbon electrodes

The electrochemical oxidation of fisetin (FIS) on glassy carbon (GC) electrodes is studied in 15% dimethyl sulfoxide (DMSO) +85% pH 4.00 and 7.00 buffer solutions by cyclic (CV) and square-wave (SWV) voltammetries. The first oxidation peak of FIS showed an adsorption/diffusion mixed control, when studies were performed in solutions in the presence of FIS. Therefore, the FIS adsorption on the GC electrode surface could be inferred from cyclic voltammograms recorded in supporting electrolyte solutions, where a quasi-reversible redox couple was defined at both pH values. These findings show that both the reactant and the product of the electrode process are adsorbed on the electrode surface, being the surface redox couple slightly better defined at pH 4.00 than 7.00. The Frumkin adsorption isotherm was the best to describe the specific interaction of FIS with GC electrodes, using a fitting procedure of experimental fractional surface coverage (θ) vs. FIS bulk concentration (cFIS). Moreover, we used the SWV to obtain a full characterization of the surface redox couple, applying the combination of the "quasi-reversible maximum" and the "splitting of the net voltammetric peak" methods. Values of (0.340 ± 0.003) V, 41 s-1, and (0.49 ± 0.04) were determined for the formal potential, the formal rate constant, and the anodic transfer coefficient, respectively.Fil: Maza, Eliana María. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Moressi, Marcela Beatriz. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química; ArgentinaFil: Fernández, Héctor. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química; ArgentinaFil: Zon, María Alicia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

Amine-appended polyaniline as a water dispersible electroactive polyelectrolyte and its integration into functional self-assembled multilayers

We present an effective and simple method for the synthesis of poly(3-aminobenzylamine) (PABA) using a chemical oxidation strategy in aqueous solution. The polymer was characterized by NMR, LDI-TOF mass spectrometry, UV-visible, XPS and ATR-FTIR spectroscopies. Stable acidic dispersions were employed for the construction of layer-by-layer assembled films with polyanions, which effectively act as dopants of the electroactive component as revealed by spectroscopic analysis. The assembled films were electroactive in neutral solutions, probably owing to the combination of the doping effect by the polyanions and the self-doping effect of the protonated amino groups of the PABA backbone. These layers showed an electrocatalytic effect on the ascorbic acid oxidation. The advantages of employing PABA instead of polyaniline include improved electroactivity in neutral solution, good processability owing to its higher solubility in acidic solutions and increased interaction with anionic counterparts, which may propel its integration with electroactive biomolecules or conducting nanomaterials for the design of bioelectrochemical devices and energy storage applications.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasConsejo Nacional de Investigaciones Científicas y Técnica

Amine-appended polyaniline as a water dispersible electroactive polyelectrolyte and its integration into functional self-assembled multilayers

We present an effective and simple method for the synthesis of poly(3-aminobenzylamine) (PABA) using a chemical oxidation strategy in aqueous solution. The polymer was characterized by NMR, LDI-TOF mass spectrometry, UV-visible, XPS and ATR-FTIR spectroscopies. Stable acidic dispersions were employed for the construction of layer-by-layer assembled films with polyanions, which effectively act as dopants of the electroactive component as revealed by spectroscopic analysis. The assembled films were electroactive in neutral solutions, probably owing to the combination of the doping effect by the polyanions and the self-doping effect of the protonated amino groups of the PABA backbone. These layers showed an electrocatalytic effect on the ascorbic acid oxidation. The advantages of employing PABA instead of polyaniline include improved electroactivity in neutral solution, good processability owing to its higher solubility in acidic solutions and increased interaction with anionic counterparts, which may propel its integration with electroactive biomolecules or conducting nanomaterials for the design ofbioelectrochemical devices and energy storage applications.Fil: Marmisollé, Waldemar Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Maza, Eliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Moya, Sergio. Soft Matter Nanotechnology Group; EspañaFil: Azzaroni, Omar. Soft Matter Nanotechnology Group; Españ

Amine-appended polyaniline as a water dispersible electroactive polyelectrolyte and its integration into functional self-assembled multilayers

We present an effective and simple method for the synthesis of poly(3-aminobenzylamine) (PABA) using a chemical oxidation strategy in aqueous solution. The polymer was characterized by NMR, LDI-TOF mass spectrometry, UV-visible, XPS and ATR-FTIR spectroscopies. Stable acidic dispersions were employed for the construction of layer-by-layer assembled films with polyanions, which effectively act as dopants of the electroactive component as revealed by spectroscopic analysis. The assembled films were electroactive in neutral solutions, probably owing to the combination of the doping effect by the polyanions and the self-doping effect of the protonated amino groups of the PABA backbone. These layers showed an electrocatalytic effect on the ascorbic acid oxidation. The advantages of employing PABA instead of polyaniline include improved electroactivity in neutral solution, good processability owing to its higher solubility in acidic solutions and increased interaction with anionic counterparts, which may propel its integration with electroactive biomolecules or conducting nanomaterials for the design of bioelectrochemical devices and energy storage applications.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasConsejo Nacional de Investigaciones Científicas y Técnica

Layer-by-Layer Assembled Microgels Can Combine Conflicting Properties: Switchable Stiffness and Wettability without Affecting Permeability

Responsive interfacial architectures of practical interest commonly require the combination of conflicting properties in terms of their demand upon material structure. Switchable stiffness, wettability, and permeability, key features for tissue engineering applications, are in fact known to be exclusively interdependent. Here, we present a nanoarchitectonic approach that decouples these divergent properties by the use of thermoresponsive microgels as building blocks for the construction of three-dimensional arrays of interconnected pores. Layer-by-layer assembled poly(N-isopropylacrylamide-co-methacrylic acid) microgel films were found to exhibit an increase in hydrophobicity, stiffness, and adhesion properties upon switching the temperature from below to above the lower critical solution temperature, whereas the permeability of redox probes through the film remained unchanged. Our findings indicate that the switch in hydrophilicity and nanomechanical properties undergone by the microgels does not compromise the porosity of the film, thus allowing the free diffusion of redox probes through the polymer-free volume of the submicrometer pores. This novel approach for decoupling conflicting properties provides a strategic route for creating tailorable scaffolds with unforeseen functionalities.Fil: Maza, Eliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Von Bilderling, Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Cortez, María Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Díaz, Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Bianchi, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Microscopías Avanzadas; ArgentinaFil: Pietrasanta, Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Giussi, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Azzaroni, Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

Layer-by-Layer Assembled Microgels Can Combine Conflicting Properties: Switchable Stiffness and Wettability without Affecting Permeability

Responsive interfacial architectures of practical interest commonly require the combination of conflicting properties in terms of their demand upon material structure. Switchable stiffness, wettability, and permeability, key features for tissue engineering applications, are in fact known to be exclusively interdependent. Here, we present a nanoarchitectonic approach that decouples these divergent properties by the use of thermoresponsive microgels as building blocks for the construction of three-dimensional arrays of interconnected pores. Layer-by-layer assembled poly(N-isopropylacrylamide-co-methacrylic acid) microgel films were found to exhibit an increase in hydrophobicity, stiffness, and adhesion properties upon switching the temperature from below to above the lower critical solution temperature, whereas the permeability of redox probes through the film remained unchanged. Our findings indicate that the switch in hydrophilicity and nanomechanical properties undergone by the microgels does not compromise the porosity of the film, thus allowing the free diffusion of redox probes through the polymer-free volume of the submicrometer pores. This novel approach for decoupling conflicting properties provides a strategic route for creating tailorable scaffolds with unforeseen functionalities.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Highly-organized stacked multilayers: Via layer-by-layer assembly of lipid-like surfactants and polyelectrolytes. Stratified supramolecular structures for (bio)electrochemical nanoarchitectonics

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 "nanoarchitectonics" as well as evolving technological applications. Herein, we report on the facile preparation and application of highly organized stacked multilayers via layer-by-layer assembly of lipid-like surfactants and polyelectrolytes. Polyelectrolyte multilayers with high degree of stratification of the internal structure were constructed through consecutive assembly of polyallylamine and dodecyl phosphate, a lipid-like surfactant that act as a structure-directing agent. We show that multilayers form well-defined lamellar hydrophilic/hydrophobic domains oriented parallel to the substrate. More important, X-ray reflectivity characterization conclusively revealed the presence of Bragg peaks up to fourth order, evidencing the highly stratified structure of the multilayer. Additionally, hydrophobic lamellar domains were used as hosts for ferrocene in order to create an electrochemically active film displaying spatially-addressed redox units. Stacked multilayers were then assembled integrating redox-tagged polyallylamine and glucose oxidase into the stratified hydrophilic domains. Bioelectrocatalysis and "redox wiring" in the presence of glucose was demonstrated to occur inside the stratified multilayer.Fil: Cortez, María Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Lorenzo, Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Marmisollé, Waldemar Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Von Bilderling, Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Maza, Eliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Pietrasanta, Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Battaglini, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Ceolin, Marcelo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Azzaroni, Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

Highly-organized stacked multilayers: Via layer-by-layer assembly of lipid-like surfactants and polyelectrolytes : Stratified supramolecular structures for (bio)electrochemical nanoarchitectonics

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 "nanoarchitectonics" as well as evolving technological applications. Herein, we report on the facile preparation and application of highly organized stacked multilayers via layer-by-layer assembly of lipid-like surfactants and polyelectrolytes. Polyelectrolyte multilayers with high degree of stratification of the internal structure were constructed through consecutive assembly of polyallylamine and dodecyl phosphate, a lipid-like surfactant that act as a structure-directing agent. We show that multilayers form well-defined lamellar hydrophilic/hydrophobic domains oriented parallel to the substrate. More important, X-ray reflectivity characterization conclusively revealed the presence of Bragg peaks up to fourth order, evidencing the highly stratified structure of the multilayer. Additionally, hydrophobic lamellar domains were used as hosts for ferrocene in order to create an electrochemically active film displaying spatially-addressed redox units. Stacked multilayers were then assembled integrating redox-tagged polyallylamine and glucose oxidase into the stratified hydrophilic domains. Bioelectrocatalysis and "redox wiring" in the presence of glucose was demonstrated to occur inside the stratified multilayer.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasConsejo Nacional de Investigaciones Científicas y Técnica

Highly-organized stacked multilayers: Via layer-by-layer assembly of lipid-like surfactants and polyelectrolytes : Stratified supramolecular structures for (bio)electrochemical nanoarchitectonics

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 "nanoarchitectonics" as well as evolving technological applications. Herein, we report on the facile preparation and application of highly organized stacked multilayers via layer-by-layer assembly of lipid-like surfactants and polyelectrolytes. Polyelectrolyte multilayers with high degree of stratification of the internal structure were constructed through consecutive assembly of polyallylamine and dodecyl phosphate, a lipid-like surfactant that act as a structure-directing agent. We show that multilayers form well-defined lamellar hydrophilic/hydrophobic domains oriented parallel to the substrate. More important, X-ray reflectivity characterization conclusively revealed the presence of Bragg peaks up to fourth order, evidencing the highly stratified structure of the multilayer. Additionally, hydrophobic lamellar domains were used as hosts for ferrocene in order to create an electrochemically active film displaying spatially-addressed redox units. Stacked multilayers were then assembled integrating redox-tagged polyallylamine and glucose oxidase into the stratified hydrophilic domains. Bioelectrocatalysis and "redox wiring" in the presence of glucose was demonstrated to occur inside the stratified multilayer.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasConsejo Nacional de Investigaciones Científicas y Técnica