Tuning the Chemical and Electrochemical Properties of Paper-Based Carbon Electrodes by Pyrolysis of Polydopamine.

Electrochemical paper-based analytical devices represent an important platform for portable, low-cost, affordable, and decentralized diagnostics. For this kind of application, chemical functionalization plays a pivotal role to ensure high clinical performance by tuning surface properties and the area of electrodes. However, controlling different surface properties of electrodes by using a single functionalization route is still challenging.

Scalable and green formation of graphitic nanolayers produces highly conductive pyrolyzed paper toward sensitive electrochemical sensors.

While pyrolyzed paper (PP) is a green and abundant material that can provide functionalized electrodes with wide detection windows for a plethora of targets, it poses long-standing challenges against sensing assays such as poor electrical conductivity, with resistivities generally higher than 200.0 mΩ cm (, gold and silver show resistivities 1000-fold lower, ∼0.2 mΩ cm).

Toxicity mitigation and biodistribution of albumin corona coated graphene oxide and carbon nanotubes in Caenorhabditis elegans.

In this work, the toxicity and biodistribution of graphene oxide (GO) and oxidized multi-walled carbon nanotubes (MWCNT) were investigated in Caenorhabditis elegans. Bovine serum albumin (BSA) was selected as a model protein to evaluate the influence of protein corona formation on materials physicochemical properties, colloidal stability, and toxicity. Biological assays were performed to assess the effects of bare and albumin corona coated materials on survival, oxidative stress, intestinal barrier permeability, growth, reproduction, and fertility.

Fast and efficient electrochemical thinning of ultra-large supported and free-standing MoS layers on gold surfaces.

Molybdenum disulfide (MoS) is a very promising layered material for electrical, optical, and electrochemical applications because of its unique and outstanding properties. To unlock its full potential, among different preparation routes, electrochemistry has gain interest due to its simple, fast, scalable and simple instrumentation. However, obtaining large-area monolayer MoS that will enable the fabrication of novel electronic and electrochemical devices is still challenging.

Mitigation of graphene oxide toxicity in C. elegans after chemical degradation with sodium hypochlorite.

Graphene oxide (GO) is a promising and strategic carbon-based nanomaterial for innovative and disruptive technologies. It is therefore essential to address its environmental health and safety aspects. In this work, we evaluated the chemical degradation of graphene oxide by sodium hypochlorite (NaClO, bleach water) and its consequences over toxicity, on the nematode Caenorhabditis elegans.

Exploring the Hierarchical Structure and Alignment of Wood Cellulose Fibers for Bioinspired Anisotropic Polymeric Composites.

Materials found in nature have their properties tuned by the chemical composition and hierarchical organization of their structures. Wood is one example of natural material which has properties tuned by its multi-scale hierarchical organization. The cellulose microfibril angle is critical for physical and mechanical properties of wood.

Deterministic control of surface mounted metal-organic framework growth orientation on metallic and insulating surfaces.

Surface-Mounted Metal-Organic Frameworks (SURMOFs) are promising materials with a wide range of applications and increasing interest in different technological fields. The use of SURMOFs as both the active and passive tail in electronic devices is one of the most exciting possibilities for such a hybrid material. In such a context, the adhesion, roughness, and crystallinity control of SURMOF thin films are challenging and have limited their application in new functional electronic devices.

The Positive Fate of Biochar Addition to Soil in the Degradation of PHBV-Silver Nanoparticle Composites.

The environmental contamination of soils by polymeric and nanomaterials is an increasing global concern. Polymeric composites containing silver nanoparticles (AgNP) are collectively one of the most important products of nanotechnology due to their remarkable antimicrobial activity. Biochars are a promising resource for environmental technologies for remediation of soils considering their high inorganic and organic pollutant adsorption capacity and microbial soil consortium stimulation.

Analysis of the effects of mesoporous silica particles SBA-15 and SBA-16 in Streptococcus pneumoniae transformation process.

Streptococcus pneumoniae are natural competent bacteria which requires the presence of a pheromone-like molecule to do the transformation process. This study verified the influence of mesoporous silica (SBA-15 and SBA-16) on the transformation process in S. pneumoniae using a donor DNA obtained from a mutant strain of this microorganism (Sp360∆luxS).

Microstructural characterization of nanocellulose foams prepared in the presence of cationic surfactants.

In this work, we explore the architecture of highly porous foams based on cellulose nanofibers (CNFs) prepared by using cationic surfactants (e.g., CTAB, CTAB, and CTAB) as modifying agents.

Functionalization of Mesoporous Silicas as Strategy for Obtaining Nanocomposites with Controlled Graphitic Domains Quantity and Carbon Content.

We report in this work the use of a synthetic procedure to prepare silica-carbon composites with controlled carbon content and number of graphitic nanocarbon domains. This synthetic protocol was applied to prepare carbon nanostructures supported at two different amorphous silicas that have similar disordered pore system structure but different specific surface areas and pore volumes. The carbon nanostructures were obtained by the silica surface grafting with different amounts of 2,3-dihydroxynaphthalene (DN) using a dehydration reaction followed by pyrolysis at temperatures between 973 and 1173 K.

Coating carbon nanotubes with humic acid using an eco-friendly mechanochemical method: Application for Cu(II) ions removal from water and aquatic ecotoxicity.

In this work, industrial grade multi-walled carbon nanotubes (MWCNT) were coated with humic acid (HA) for the first time by means of a milling process, which can be considered an eco-friendly mechanochemical method to prepare materials and composites. The HA-MWCNT hybrid material was characterized by atomic force microscopy (AFM), scanning electron microscopies (SEM and STEM), X-ray photoelectron spectroscopy (XPS), termogravimetric analysis (TGA), and Raman spectroscopy. STEM and AFM images demonstrated that the MWCNTs were efficiently coated by the humic acid, thus leading to an increase of 20% in the oxygen content at the nanotube surface as observed by the XPS data.

Flexible and Foldable Fully-Printed Carbon Black Conductive Nanostructures on Paper for High-Performance Electronic, Electrochemical, and Wearable Devices.

In this work, we demonstrate the first example of fully printed carbon nanomaterials on paper with unique features, aiming the fabrication of functional electronic and electrochemical devices. Bare and modified inks were prepared by combining carbon black and cellulose acetate to achieve high-performance conductive tracks with low sheet resistance. The carbon black tracks withstand extremely high folding cycles (>20 000 cycles), a new record-high with a response loss of less than 10%.

Structural aspects of graphitic carbon modified SBA-15 mesoporous silica and biological interactions with red blood cells and plasma proteins.

Functional mesoporous materials have been worldwide studied for different applications. Mesoporous silicas are highlighted due to the synthetic possibilities for the preparation of such materials with different particle sizes and morphologies, and controlled pores sizes and structures. Moreover, the silica superficial silanol groups are explored in several chemical modifications, leading to functional materials with tuned functionalities and properties.

Direct Drawing Method of Graphite onto Paper for High-Performance Flexible Electrochemical Sensors.

A simple and fast fabrication method to create high-performance pencil-drawn electrochemical sensors is reported for the first time. The sluggish electron transfer observed on bare pencil-drawn surfaces was enhanced using two electrochemical steps: first oxidizing the surface and then reducing it in a subsequent step. The heterogeneous rate constant was found to be 5.

Activated carbon from pyrolysed sugarcane bagasse: Silver nanoparticle modification and ecotoxicity assessment.

Activated carbon from pyrolysed sugarcane bagasse (ACPB) presented pore size ranges from 1.0 to 3.5nm, and surface area between 1200 and 1400m(2)g(-1) that is higher than commonly observed to commercial activated carbon.

Ion-exchange properties of imidazolium-grafted SBA-15 toward AuCl4(-) anions and their conversion into supported gold nanoparticles.

Imidazolium groups were successfully prepared and grafted on the surface of SBA-15 mesoporous silica. The ion-exchange properties of the functionalized porous solid (SBA-15/R(+)Cl(-)) toward AuCl(4)(-) anions were evaluated through an ion-exchange isotherm. The calculated values of the equilibrium constant (log β = 4.