Zn-Salphen Acrylic Films Powered by Aggregation-Induced Enhanced Emission for Sensing Applications.

Zn(II) complexes possess attractive characteristics for supramolecular chemistry, catalysis, and optoelectronic applications, while Zn-Salphen counterparts are also suitable as chemical sensors, although limited by solution-based to date. In this study, we report the synthesis of new polymers from methyl methacrylate, n-butyl acrylate, and a non-symmetrical Zn-Salphen complex. We show that this low-fluorescent complex exhibits aggregation-induced emission enhancement (AIEE) properties and that, the incorporation of AIEE complexes into a polymeric matrix make it possible to achieve fluorescent films with enhanced fluorescence suitable for sensing applications.

Synthesis and Cytotoxicity Studies of Br-Substituted Salphen Organic Compounds.

We present the synthesis and characterization of organic Salphen compounds containing bromine substituents at the para/ortho-para positions, in their symmetric and non-symmetric versions, and describe the X-ray structure and full characterization for the new unsymmetrical varieties. We report for the first time antiproliferative activity in metal-free brominated Salphen compounds, by evaluations in four human cancer cell lines, cervix (HeLa), prostate (PC-3), lung (A549) and colon (LS 180) and one non-cancerous counterpart (ARPE-19). We assessed in vitro cell viability against controls using the MTT assay ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide)) and determined the concentration required for 50 % growth inhibition (IC ), together with their selectivity vs.

Turing patterns by supramolecular self-assembly of a single salphen building block.

In the 1950s, Alan Turing showed that concerted reactions and diffusion of activating and inhibiting chemical species can autonomously generate patterns without previous positional information, thus providing a chemical basis for morphogenesis in Nature. However, access to these patterns from only one molecular component that contained all the necessary information to execute agonistic and antagonistic signaling is so far an elusive goal, since two or more participants with different diffusivities are a must. Here, we report on a single-molecule system that generates Turing patterns arrested in the solid state, where supramolecular interactions are used instead of chemical reactions, whereas diffusional differences arise from heterogeneously populated self-assembled products.

Acrylic Polymers Containing a Nickel Salphen Complex: An Approach to Supramolecular and Macromolecular Systems.

Invited for this month's cover are Prof. Martha Escárcega-Bobadilla and Prof. Gustavo Zelada-Guillén, collaborators from the National Autonomous University of Mexico (UNAM).

Acrylic Polymers Containing a Nickel Salphen Complex: An Approach to Supramolecular and Macromolecular Systems.

The synthesis, characterization and crystallographic analysis is reported of a new Nickel Salphen complex and its radical copolymerization with n-butyl acrylate and methyl methacrylate to produce novel host macromolecules with tunable association against guest anions. Spectrophotometric titrations of the complex and of the polymers revealed that a supramolecular regulation of guest-binding accessibility was enabled by the number of Ni-Salphen units per chain. The latter content in turn, determined the chain size and molecular weight uniformity upon polymerization, and likely increased the strength in interchain/intrachain non-covalent interactions over the nickel center and the acrylic domains.

Control of pH-Responsiveness in Graphene Oxide Grafted with Poly-DEAEMA via Tailored Functionalization.

Polymer-grafted nanomaterials based on carbon allotropes and their derivatives (graphene oxide (GO), etc.) are typically prepared by successive reaction stages that depend upon the initial functionalities in the nanostructure and the polymerization type needed for grafting. However, due to the multiple variables involved in the functionalization steps, it is commonly difficult to predict the properties in the final product and to correlate the material history with its final performance.

Synthesis of a Novel Zn-Salphen Building Block and Its Acrylic Terpolymer Counterparts as Tunable Supramolecular Recognition Systems.

In this work, we present the synthesis of a novel Zn-Salphen complex containing an allyl group, which was used as building block in the further preparation of a new family of functional terpolymers. These polymers were obtained through radical co-polymerization with methyl metacrylate (MMA) and -butyl acrylate (BuA) in different ratios. The supramolecular recognition behavior of each polymer was evaluated via potentiometric measurements against selected anions in aqueous media.

Grafting Multiwalled Carbon Nanotubes with Polystyrene to Enable Self-Assembly and Anisotropic Patchiness.

We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a free-radical polymerization strategy to enable the modulation of the nanotube surface properties and produce supramolecular self-assembly of the nanostructures. First, a selective hydroxylation of the pristine nanotubes through a biphasic catalytically mediated oxidation reaction creates superficially distributed reactive sites at the sidewalls. The latter reactive sites are subsequently modified with methacrylic moieties using a silylated methacrylic precursor to create polymerizable sites.

Nanorings and rods interconnected by self-assembly mimicking an artificial network of neurons.

Molecular electronics based on structures ordered as neural networks emerges as the next evolutionary milestone in the construction of nanodevices with unprecedented applications. However, the straightforward formation of geometrically defined and interconnected nanostructures is crucial for the production of electronic circuitry nanoequivalents. Here we report on the molecularly fine-tuned self-assembly of tetrakis-Schiff base compounds into nanosized rings interconnected by unusually large nanorods providing a set of connections that mimic a biological network of neurons.

Carbon nanotube-based aptasensors for the rapid and ultrasensitive detection of bacteria.

In this paper we present a new generation of potentiometric biosensors based on carbon nanotubes (transducer layer of the biosensor) and aptamers (sensing layer of the biosensor) for the ultralow and selective detection of microorganisms. We show that with these aptasensors we were able to detect a few CFU of the target bacteria almost in real-time, both in buffered and in real samples.

Ultrasensitive and real-time detection of proteins in blood using a potentiometric carbon-nanotube aptasensor.

Potentiometric sensing represents the preferred technique in many routine measurements of pH and ions. Unfortunately, the simplicity of the technique has not been exploited so far in high throughput biomolecular sensing. In this work, we demonstrate the capabilities of the hybrid functional material carbon nanotubes/aptamer for the creation of a new generation of nuclease-resistant aptasensors using the potentiometric transduction capabilities of single-walled carbon nanotubes in combination with the recognition capabilities of a protein-specific RNA aptamer.

Label-free detection of Staphylococcus aureus in skin using real-time potentiometric biosensors based on carbon nanotubes and aptamers.

In this paper we report the first biosensor that is able to detect Staphylococcus aureus in real-time. A network of single-walled carbon nanotubes (SWCNTs) acts as an ion-to-electron potentiometric transducer and anti-S. aureus aptamers are the recognition element.

Real-time potentiometric detection of bacteria in complex samples.

Detecting and identifying pathogen bacteria is essential to ensure quality at all stages of the food chain and to diagnose and control microbial infections. Traditional detection methods, including those based on cell culturing, are tedious and time-consuming, and their further application in real samples generally implies more complex pretreatment steps. Even though state-of-the-art techniques for detecting microorganisms enable the quantification of very low concentrations of bacteria, to date it has been difficult to obtain successful results in real samples in a simple, reliable, and rapid manner.

Nanostructured materials in potentiometry.

Potentiometry is a very simple electrochemical technique with extraordinary analytical capabilities. It is also well known that nanostructured materials display properties which they do not show in the bulk phase. The combination of the two fields of potentiometry and nanomaterials is therefore a promising area of research and development.