Calculation of CO adsorption capacity of single iron(II)- porphyrin and related electron transfer behavior by DFT theory

The effect of CO adsorption on the electron transport behavior of single iron(II)- porphyrin molecular wire with sulfur end groups bonded to two gold electrodes is investigated using nonequilibrium Green's function formalism combined with firstprinciples density functional theory. The current-voltage characteristics of the single Fe-porphyrin molecular wires with and without CO adsorption are calculated. The results demonstrate that Fe-porphyrin molecular wire shows a negative differential resistance (NDR) at 2.0

Supramolecular Detection of a Nerve Agent Simulant by Fluorescent Zn–Salen Oligomer Receptors

We report on new Zn–Salen oligomer receptors able to recognize a nerve agent simulant, namely dimethyl methylphosphonate (DMMP), by a supramolecular approach. In particular, three Zn-Salen oligomers (Zn–Oligo–A, –B, and –C), differing by the length distribution, were obtained and characterized by NMR, Gel Permeation Chromatography (GPC), UV-Vis, and fluorescence spectroscopy. Furthermore, we investigated their recognition properties towards DMMP by using fluorescence measurements. We found that the recognition ability depends on the length of the oligomeric chain, and the Zn–Oligo–C shows a binding constant value higher than those already reported in literature for the DMMP detection

TiO2-Based Nanocomposites Thin Film Having Boosted Photocatalytic Activity for Xenobiotics Water Pollution Remediation

Photocatalytic remediation represents a potential sustainable solution to the abatement of xenobiotic pollutants released within the water environment. Aeroxide® P25 titanium dioxide nanoparticles (TiO2 NPs) are well-known as one of the most efficient photocatalysts in several applications, and have also been investigated in water remediation as suspended powder. Recently, their application in the form of thin films has been revealed as a potential alternative to avoid time-consuming filtration processes. Polymers represent suitable substrates to immobilize TiO2 NPs, allowing further production of thin films that can be exploited as a photoactive coating for environmental remediation. Nevertheless, the methods adopted to immobilize TiO2 NPs on polymer matrix involve time-consuming procedures and the use of several reactants. Here, titanium dioxide-based nanocomposites (NCx) were obtained through a new approach based on Methyl Methacrylate in situ bulk polymerization and were compared with a blended mixture (BL). Their morphology and chemical–physical properties were investigated through Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), UV–Vis, and Raman spectroscopies. It was revealed that the in situ approach deeply influences the chemical–physical interactions between the polymer matrix and TiO2 NPs. Photocatalytic experiments revealed the boosted photodegradation activity of NCx thin films, induced by the in situ approach. The photodegradation of paraquat and acetaminophen was also ascertained

Solar light mediated anthracene abatement in aerated aqueous media using a thermoplastic nanocomposite photocatalyst

Polycyclic aromatic hydrocarbons (PAHs) are the most widespread xenobiotic pollutants in water and their abatement usually involves expensive and energy-consuming treatments. In this work, anthracene (AN) was selected as the recalcitrant model of PAHs and its solar light-stimulated heterogeneous photocatalytic abatement in aerated aqueous media was investigated using a new TiO derived thermoplastic nanocomposite in thin film form. The results were also compared with the benchmark TiO photocatalyst in slurry form. Finally, the possible contribution of reactive intermediates such as hydroxyl radical, AN radical cation and singlet oxygen, was investigated by using a hydroxyl radical trap and laser flash photolysis. Based on the obtained results, a feasible mechanism for AN photodegradation, which involves hydroxyl radical as the key oxidizing species is proposed.This research was funded by the University of Catania (Piano di incentivi per la ricerca di Ateneo, PIACERI–Linea 2)

"Click" on PLGA-PEG and hyaluronic acid: gaining access to anti-leishmanial pentamidine bioconjugates

Pentamidine (Pent), an antiparasitic drug used for the treatment of visceral leishmaniasis, has been modified with terminal azide groups and conjugated to two different polymer backbones (PLGA-PEG [PP] copolymer and hyaluronic acid [HA]) armed with alkyne end-groups. The conjugation has been performed by Copper Catalyzed Azido Alkyne Cycloaddition (CuAAC) using CuSO4/sodium ascorbate as metal source. The novel PP-Pent and HA-Pent bioconjugates are proposed, respectively, as non-targeted and targeted drug delivery systems against Leishmania infections. Moreover, Pent has been encapsulated into PP nanoparticles by the oil-in-water emulsion method, with the aim to compare the biological activity of the bioconjugates with that of the classical drug-loaded delivery system that physically entraps the therapeutic agent. Biological assays against Leishmania infantum amastigote-infected macrophages and primary macrophages revealed that Pent, either covalently conjugated with polymers or loaded into polymeric nanoparticles, turned out to be more potent and less toxic than the free Pent. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2778–2785, 2018. © 2017 Wiley Periodicals, Inc

Supramolecular Polymer Networks Based on Calix[5]arene Tethered Poly(<i>p</i>‑phenyleneethynylene)

A poly­(<i>p</i>-phenyleneethynylene) polymer (<b>PC­[5]</b>), featuring two π-rich cone-like calix[5]­arene cavities (assembling cores) connected to a rigid <i>p</i>-phenyleneethynylene spacer, was synthesized by a Pd-catalyzed cross-coupling reaction. NMR investigations provide support for the self-assembly dynamics of <b>PC­[5]</b> (homopolytopic host molecule) and complementary 1,10-decanediyldiammonium (<b>C</b>_<b>10</b>) guest in solution in the construction of supramolecular polymer networks. Upon variation of the host/guest molar ratio, two distinct types of assemblies were identified in solution: a 1:2 bis-endo-cavity assembly <b>C</b>_<b>10</b>⊂<b>PC­[5]</b>⊃<b>C</b>_<b>10</b> (<b>PC­[5]</b>_<b>cap</b>) and a polycapsular polymer network assembly <b>PC­[5]</b>⊃<b>C</b>_<b>10</b>⊂<b>PC­[5]</b> (<b>PC­[5]</b>_<b>net</b>). The reversibility of the assembly/disassembly processes of <b>PC­[5]</b>_<b>net</b> and <b>PC­[5]</b>_<b>cap</b> upon successive additions of Et₃N and TFA was also investigated. AFM analysis of <b>PC­[5]</b>_<b>net</b> revealed the formation of a homogeneous continuous network on surface