Blue-light-driven photoactivity of L-cysteine-modified graphene quantum dots and their antibacterial effects.

The widespread abuse of traditional antibiotics has led to a global rise in antibiotic-resistant bacteria, which give in return unprecedented health risks. Therefore, there is a large and urgent need for the development of new, smart antibacterial agents able to efficiently kill or inhibit bacterial growth. In this study, we investigated the antibacterial activity of S, N-doped Graphene Quantum Dots (GQDs) as a light-triggered antibacterial agent.

Self-Cleaning Bending Sensors Based on Semitransparent ZnO Nanostructured Films.

The design of multifunctional nanostructured materials is the key to the development of smart wearable devices. For instance, nanostructures endowed with both piezoelectric and photocatalytic activities could well be the workhorse for solar-light-driven self-cleaning wearable sensors. In this work, a simple strategy for the assembly of a flexible, semitransparent piezophotocatalytic system is demonstrated by leveraging rational wet chemistry synthesis of ZnO-based nanosheets/nanoflowers (NSs/NFs) under basic pH conditions onto flexible ITO/PET supports.

Gamma-Ray-Induced Structural Transformation of GQDs towards the Improvement of Their Optical Properties, Monitoring of Selected Toxic Compounds, and Photo-Induced Effects on Bacterial Strains.

Structural modification of different carbon-based nanomaterials is often necessary to improve their morphology and optical properties, particularly the incorporation of N-atoms in graphene quantum dots (GQDs). Here, a clean, simple, one-step, and eco-friendly method for N-doping of GQDs using gamma irradiation is reported. GQDs were irradiated in the presence of the different ethylenediamine (EDA) amounts (1 g, 5 g, and 10 g) and the highest % of N was detected in the presence of 10 g.

Influence of Calcium Carbonate Nanoparticles on the Soil Burial Degradation of Polybutyleneadipate-Co-Butylenetherephthalate Films.

A polybutyleneadipate-co-butylenetherephthalate (PBAT) sample, commercially known as Ecoflex, was processed via melt extrusion with CaCO nanoparticles coated with a hydrophobic coating. Blown films of PBAT and two composites with nanofiller (2% and 5%wt) were prepared and degradation tests in soil at 30 °C up to 180 days were carried out with weight loss measurements. Furthermore, biodegradation test according to ISO 14851 was carried out at 30 °C.

Lead(II) ions adsorption onto amyloid particulates: An in depth study.

The production of new cost-effective biocompatible sorbent sustainable materials, with natural origins, able to remove heavy metals from water resources is nowadays highly desirable in order to reduce pollution and increase clean water availability. In this context, self-assembled protein materials with amyloid structures seem to have a great potential as natural platform for a broader development of highly-tunable structures. In this work we show how protein particulates, a generic form of protein aggregates, with spherical micro sized shape can be used as adsorbents of Pb ions from aqueous solution.

Improved Photocatalytic Activity of Polysiloxane TiO Composites by Thermally Induced Nanoparticle Bulk Clustering and Dye Adsorption.

Fine control of nanoparticle clustering within polymeric matrices can be tuned to enhance the physicochemical properties of the resulting composites, which are governed by the interplay of nanoparticle surface segregation and bulk clustering. To this aim, out-of-equilibrium strategies can be leveraged to program the multiscale organization of such systems. Here, we present experimental results indicating that bulk assembly of highly photoactive clusters of titanium dioxide nanoparticles within an in situ synthesized polysiloxane matrix can be thermally tuned.

Aqueous Processed Biopolymer Interfaces for Single-Cell Microarrays.

Single-cell microarrays are emerging tools to unravel intrinsic diversity within complex cell populations, opening up new approaches for the in-depth understanding of highly relevant diseases. However, most of the current methods for their fabrication are based on cumbersome patterning approaches, employing organic solvents and/or expensive materials. Here, we demonstrate an unprecedented green-chemistry strategy to produce single-cell capture biochips onto glass surfaces by all-aqueous inkjet printing.

Bending Sensors Based on Thin Films of Semitransparent Bithiophene-Fulleropyrrolidine Bisadducts.

A novel bithiophene-fulleropyrrolidine bisadducts system (bis-Th2PC ) was synthesized and electropolymerized by chronoamperometry onto flexible ITO/PET substrates. The resulting semitransparent thin film was characterized by XPS, FT-IR, cyclic voltammetry and optical techniques, confirming the good outcome of the electropolymerization process. AFM investigations permitted to highlight an inherent disordered granular morphology, in which the grain-to-grain separation depends upon the application of bending.

Synergies and compromises between charge and energy transfers in three-component organic solar cells.

In this paper, we developed different three-component organic heterojunction structures supported by PET/ITO substrates with the aim to study the possible synergies and/or compromises between charge transfer (CT) and energy transfer (ET) processes in organic solar cells (OSCs). As components, we employed poly(3-hexylthiophene-2,5-diyl) (P3HT; donor), [6,6]-phenyl-C61-butyric acid methyl ester (PCBM; acceptor) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) that is known to give good ET to P3HT. At first, we observed that in a planar heterojunction (PHJ) solar cell, F8BT has to be properly located in between P3HT and PCBM to get a cascade energy level configuration allowing for a better CT and power conversion efficiency.

Ambipolar MoS Transistors by Nanoscale Tailoring of Schottky Barrier Using Oxygen Plasma Functionalization.

One of the main challenges to exploit molybdenum disulfide (MoS) potentialities for the next-generation complementary metal oxide semiconductor (CMOS) technology is the realization of p-type or ambipolar field-effect transistors (FETs). Hole transport in MoS FETs is typically hampered by the high Schottky barrier height (SBH) for holes at source/drain contacts, due to the Fermi level pinning close to the conduction band. In this work, we show that the SBH of multilayer MoS surface can be tailored at nanoscale using soft O plasma treatments.

Synthesis, photophysical properties and structures of organotin-Schiff bases utilizing aromatic amino acid from the chiral pool and evaluation of the biological perspective of a triphenyltin compound.

Five new organotin(IV) complexes of compositions [MeSnL] (1), [MeSnL] (2), [MeSnL] (3), [PhSnLH] (4) and [PhSnLH] (5) (where L=(2S)-2-((E)-((Z)-4-hydroxypent-3-en-2-ylidene)amino)-3-(1H-indol-3-yl)propanoate, L=(2S)-(E)-2-((2-hydroxybenzylidene)amino)-3-(1H-indol-3-yl)propanoate and L=(2S)-(E)-2-((1-(2-hydroxyphenyl)ethylidene)amino)-3-(1H-indol-3-yl)propanoate were synthesized and spectroscopically characterized. The crystal structures of 1-4 were determined. For the dimethyltin derivative 2, a polymeric chain structure was observed as a result of a long Sn∙∙∙O contact involving the exocyclic carbonyl oxygen-atom from the tridentate ligand of a neighboring Sn-complex unit.

Synthesis, chemical characterization and biological activity of new histone acetylation/deacetylation specific inhibitors: a novel and potential approach to cancer therapy.

Three new triorganotin(IV) complexes of valproic acid (vp1, Me3Sn-valproate; vp2, Bu3Sn-valproate; vp3, Ph3Sn-valproate) have been synthesized and investigated by spectroscopic and biological methods. An anionic, monodentate valproate ligand was observed, ester-like coordinating the tin atom on a tetra-coordinated, monomeric environment. The structures, though, can distort towards a penta-coordination, as a consequence of a long range O···Sn interaction.

An in vitro comparative assessment with a series of new triphenyltin(IV) 2-/4-[(E)-2-(aryl)-1-diazenyl]benzoates endowed with anticancer activities: structural modifications, analysis of efficacy and cytotoxicity involving human tumor cell lines.

Four new triphenyltin(IV) complexes of composition Ph(3)SnLH (where LH=2-/4-[(E)-2-(aryl)-1-diazenyl]benzoate) (1-4) were synthesized and characterized by spectroscopic (((1))H, ((13))C and ((119))Sn NMR, IR, ((119))Sn Mössbauer) techniques in combination with elemental analysis. The ((119))Sn NMR spectroscopic data indicate a tetrahedral coordination geometry in non-coordinating solvents. The crystal structures of three complexes, Ph(3)SnL((1))H (1), Ph(3)SnL((3))H (3), Ph(3)SnL((4))H (4), were determined.

Molecular basis of the interaction of novel tributyltin(IV) 2/4-[(E)-2-(aryl)-1-diazenyl]benzoates endowed with an improved cytotoxic profile: synthesis, structure, biological efficacy and QSAR studies.

A series of tributyltin(IV) complexes based on 2/4-[(E)-2-(aryl)-1-diazenyl]benzoate ligands was synthesized, wherein the position of the carboxylate and aryl substituents (methyl, tert-butyl and hydroxyl) varies. The complexes, Bu(3)SnL(1-4)H (1-4), have been structurally characterized by elemental analysis and IR, NMR ((1)H, (13)C, and (119)Sn) and (119)Sn Mössbauer spectroscopy. All have a tetrahedral geometry in solution and a trigonal bipyramidal geometry in the solid-state, except for Bu(3)SnL(4)H (4) that was ascertained to have tetrahedral coordination by X-ray crystallography.

Diorganotin(IV) N-acetyl-L-cysteinate complexes: synthesis, solid state, solution phase, DFT and biological investigations.

Diorganotin(IV) complexes of N-acetyl-L-cysteine (H(2)NAC; (R)-2-acetamido-3-sulfanylpropanoic acid) have been synthesized and their solid and solution-phase structural configurations investigated by FTIR, Mössbauer, (1)H, (13)C and (119)Sn NMR spectroscopy. FTIR results suggested that in R(2)Sn(IV)NAC (R = Me, Bu, Ph) complexes NAC(2-) behaves as dianionic tridentate ligand coordinating the tin(IV) atom, through ester-type carboxylate, acetate carbonyl oxygen atom and the deprotonated thiolate group. From (119)Sn Mössbauer spectroscopy it could be inferred that the tin atom is pentacoordinated, with equatorial R(2)Sn(IV) trigonal bipyramidal configuration.

Dibutyltin(IV) complexes containing arylazobenzoate ligands: chemistry, in vitro cytotoxic effects on human tumor cell lines and mode of interaction with some enzymes.

Dibutyltin(IV) complexes of composition Bu₂Sn(LH)₂, where LH is a carboxylate residue derived from 2-[(E)-(5-tert-butyl-2-hydroxyphenyl)diazenyl]benzoate (L¹H) with water molecule (1), 4-[(E)-(5-tert-butyl-2-hydroxyphenyl)diazenyl]benzoate (L²H) (2) and 4-[(E)-(4-hydroxy-5-methylphenyl)diazenyl]benzoate (L³H) (3), were synthesized and characterized by spectroscopic (¹H, ¹³C and ¹¹⁹Sn NMR, IR, ¹¹⁹Sn Mössbauer) techniques. A full characterization was accomplished from the crystal structure of complex 1. The molecular structures and geometries of the complexes (1a i.

Triphenyltin(IV) 2-[(E)-2-(aryl)-1-diazenyl]benzoates as anticancer drugs: synthesis, structural characterization, in vitro cytotoxicity and study of its influence towards the mechanistic role of some key enzymes.

Triphenyltin(IV) complexes of composition [Ph(3)SnL(1)H](n) (1) and [Ph(3)SnL(2)H](n) (2) (where L(1)H = 2-[(E)-2-(3-formyl-4-hydroxyphenyl)-1-diazenyl]benzoate and L(2)H = 2-[(E)-2-(4-Hydroxy-5-methylphenyl)-1-diazenyl]benzoate) were synthesized and characterized by spectroscopic ((1)H, (13)C and (119)Sn NMR, IR, (119)Sn Mössbauer) techniques in combination with elemental analysis. The molecular structures and geometries of the complexes (1 and 2) were fully optimized using the quantum mechanical method (PM3). Complexes (1 and 2) were found to exhibit stronger cytotoxic activity in vitro across a panel of human tumour cell lines viz.

Dynamics of cell membrane passive depolarization: a phase portrait.

Does a persistent blockage of the ionic pumps bring cell membrane voltage to zero? This apparently trivial question of basic cellular Biology stirred up an intriguing problem of nonlinear dynamics. A 3-ion model based on continuity and charge conservation proves that membrane voltage actually sets on a negative value, meaning that chemical equilibrium is never reached, rather an inversion of the Na+ concentration gradient occurs, usually hours after the blockage of the pumps. Experimental tests carried out with PC12 cells incubated with Oubaine for a period of 24 hours show an increase of cytosolic Na+ of about 266 mM/l with respect to a control sample.