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Salicylate and benzoate sunscreen agents have been encapsulated by the green, fast and robust ultrasound technique in tannin microcapsules (TMCs). The generated TMCs, obtained without use of cross linking agents, were fully characterised, including encapsulation efficiencies with respect to the encapsulated actives. Release kinetics of TMCs have been studied mimicking skin conditions. Body cream base samples containing specific concentrations of microcapsules filled with sunscreen actives were prepared and showed synergistic effects in terms of UV-protection abilities generated by the interplay between sunscreen actives and natural tannin polyphenols. The synergistic effect exerted by the tannin and the controlled active release allows to reduce the amount of synthetic sunscreens needed, and does thus contribute to the development of more sustainable and environmentally benign UV-protection systems.

The photocatalytic approach is known to be one of the most promising advanced oxidation processes for the tertiary treatment of polluted water. In this paper, β-NaYF4/TiO2 composite films have been synthetized through a novel sol–gel/spin-coating approach using a mixture of β-diketonate complexes of Na and Y, and Yb3+, Tm3+, Gd3+, Eu3+ as doping ions, together with the TiO2 P25 nanoparticles. The herein pioneering approach represents an easy, straightforward and industrially appealing method for the fabrication of doped β-NaYF4/TiO2 composites. The effect of the doped β-NaYF4 phase on the photocatalytic activity of TiO2 for the degradation of methylene blue (MB) has been deeply investigated. In particular, the upconverting TiO2/β-NaYF4: 20%Yb, 2% Gd, x% Tm (x = 0.5 and 1%) and the downshifting TiO2/β-NaYF4: 10% Eu composite films have been tested on MB degradation both under UV and visible light irradiation. An improvement up to 42.4% in the degradation of MB has been observed for the TiO2/β-NaYF4: 10% Eu system after 240 min of UV irradiation.

The focus of present research is the establishment of a practical procedure for effective incorporation of multi-walled carbon nanotubes (MWCNTs) into alkali-activated materials (AAMs) with the aim of mechanical reinforcement. Investigated composite in this work was an alkali-activated matrix composed of fly ash (FA) and ground-granulated blast furnace-slag (GGBS) as solid aluminium-calcium-silicate precursors along with highly concentrated sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) as liquid alkaline activators. Na2SiO3, NaOH, and a combination of them were used for dispersion of MWCNTs. An anionic surfactant, naphthalene sulfonate (NS), and ultrasonication were applied to assist in the preparation of nanofluids. Optical microscopy, integral light transmission (ILT), and Fourier-transform infrared spectroscopy (FTIR) were performed to assess the colloidal behaviour of MWCNTs in the nanofluids. The possible dispersion mechanisms were furthermore hypothesised for each alkaline medium. Based on the outcomes, MWCNTs had the best dispersion performance in the Na2SiO3 based nanofluids. The relevant nanocomposites accordingly, in comparison to the other preparation methodologies in this research, indicated the highest improvements in flexural (65%) and compressive (30%) strengths as a consequence of 0.050 wt% MWCNT incorporation. Scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) further clarified the reinforcement functionality and microstructure refinement of the MWCNTs dispersed in the Na2SiO3 based nanofluids. Altogether, this paper represents a broad insight concerning a better understanding of MWCNTs’ interactions in alkaline activators, i.e. dispersion media, and AAMs, i.e. host matrices, to obtain the highest possible mechanical and microstructural performance of reinforced nanocomposites.

In this work, the properties of zinc oxide (ZnO) low-dimensional conductive oxide nanostructures in the aspect of their potential applications in microelectronics, in toxic gas sensing, as well as in water remediation, have been determined. ZnO nanostructured porous thin films deposited by DC reactive sputtering (RS) have been deposited on Si substrates at different temperature conditions. For surface properties and chemical morphology analysis, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) have been used. Thanks to these techniques, it was possible to obtain information on thin film surface modifications caused by the adsorption of atmospheric carbon dioxide, and by the adsorption of photodegradation products following the photocatalysis experiments. The ZnO thin films were tested for their photocatalytic properties under UV light irradiation. For this purpose, methylene blue was used as a dye model pollutant to evaluate the activity of the nanostructures. It was observed that the ZnO thin films are able to photocatalytically degrade methylene blue. These results demonstrate that properly selected zinc oxide nanostructures, currently used in toxic gas sensing, can find application in the removal of micropollutants such as dyes and pharmaceuticals present in wastewater.

Antibiotics in wastewater represent a growing and worrying menace for environmental and human health fostering the spread of antimicrobial resistance. Titanium dioxide (TiO

Magnesium plays a crucial role in many physiological functions and pathological states. Therefore, the evolution of specific and sensitive tools capable of detecting and quantifying this element in cells is a very desirable goal in biological and biomedical research. We developed a Mg2+-selective fluorescent dye that can be used to selectively detect and quantify the total magnesium pool in a number of cells that is two orders of magnitude smaller than that required by flame atomic absorption spectroscopy (F-AASAASAAS), the reference analytical method for the assessment of cellular total metal content. This protocol reports itemized steps for the synthesis of the fluorescent dye based on diaza-18-crown-6-hydroxyquinoline (DCHQ5). We also describe its application in the quantification of total intracellular magnesium in mammalian cells and the detection of this ion in vivo by confocal microscopy. The use of in vivo confocal microscopy enables the quantification of magnesium in different cellular compartments. As an example of the sensitivity of DCHQ5, we studied the involvement of Mg2+ in multidrug resistance in human colon adenocarcinoma cells sensitive (LoVo-S) and resistant (LoVo-R) to doxorubicin, and found that the concentration was higher in LoVo-R cells. The time frame for DCHQ5 synthesis is 1–2 d, whereas the use of this dye for total intracellular magnesium quantification takes 2.5 h and for ion bioimaging it takes 1–2 h.

Stepwise self-assembly processes using new lanthanide metalloligands (Ln-MLs) and silver salts have been successfully applied to isolate 4f-4d heterometallic coordination networks of four different structural types. In particular, the new lanthanide tetrakis-chelate complexes NEt4[Ln(L1)4] [HL1 = 1,3-bis(4'-cyanophenyl)-1,3-propanedione; Ln = Eu (1a), La (1b), Nd (1c), Tb (1d)] and NEt4[Ln(L2)4] (HL2 = 1,3-bis(4'-pyridyl)-1,3-propanedione; Ln = Eu (1e), Nd (1f)] have been synthesized, characterized, and reacted with different silver salts. The use of NEt4[Ln-(L1)4] allowed then to isolate and characterize i) neutral onedimensional ladder-like species of formula [Ln(L1)4Ag] [Ln = Eu (2a), La(2b), Nd(2c), Tb(2d)] and ii) their supramolecular isomers [Ln(L1)4Ag] [Ln = Eu (3a), La (3b), Nd (3c), Tb (3d)] showing a very unstable 2D network structure, iii) the cationic 2D species [Ln(L1)4Ag2]X [Ln = Eu, X = PF6-, CF3SO3-, ClO4- (4a-4c); Ln = Tb, Nd, La X = PF6 - (4d-4f)], and, only for lanthanum, iv) a fourth 2D species of formula [La(L1)4(H2O)Ag] (5) and SQL topology. Of the eight nitrile groups on the MLs potentially coordinating, only a partial number is used for networking with Ag(I), that is, only two in families 2 and 3 and four in family 4 and in network 5. Finally, the four structural types are rationalized in terms of a new "pincer-like" secondary building unit (SBU) consisting of a silver cation coordinating two central carbon atoms (γ carbon) of two different diketonate ligands on the same ML. Therefore, it is shown that compounds 5, 4, and 2-3 contain, respectively, none, one, or two of such pincer-like SBUs. The luminescence properties of the Ln-MLs and some of their polymeric species have been also investigated in solution and in the solid state.

We report a simple one-pot method for the rapid preparation of sub-10nm pure hexagonal (-phase) NaYF4-based upconverting nanoparticles (UCNPs). Using Therminol((R))66 as a co-solvent, monodisperse UCNPs could be obtained in unusually short reaction times. By varying the reaction time and reaction temperature, it was possible to control precisely the particle size and crystalline phase of the UCNPs. The upconversion (UC) luminescence properties of the nanocrystals were tuned by varying the concentrations of the dopants (Nd3+ and Yb3+ sensitizer ions and Er3+ activator ions). The size and phase-purity of the as-synthesized core and core-shell nanocrystals were assessed by using complementary transmission electron microscopy, dynamic light scattering, X-ray diffraction, and small-angle X-ray scattering studies. In-depth photophysical evaluation of the UCNPs was pursued by using steady-state and time-resolved luminescence spectroscopy. An enhancement in the UC intensity was observed if the nanocrystals, doped with optimized concentrations of lanthanide sensitizer/activator ions, were further coated with an inert/active shell. This was attributed to the suppression of surface-related luminescence quenching effects., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 613

A waste-originated one-part alkali-activated nanocomposite is introduced herein as a novel thermoelectric material. For this purpose, single-walled carbon nanotubes (SWCNTs) were utilized as nanoinclusions to create an electrically conductive network within the investigated alkali-activated construction material. Thermoelectric and microstructure characteristics of SWCNT-alkali-activated nanocomposites were assessed after 28 days. Nanocomposites with 1.0 wt.% SWCNTs exhibited a multifunctional behavior, a combination of structural load-bearing, electrical conductivity, and thermoelectric response. These nanocomposites (1.0 wt.%) achieved the highest thermoelectric performance in terms of power factor (PF), compared to the lower SWCNTs’ incorporations, namely 0.1 and 0.5 wt.%. The measured electrical conductivity (σ) and Seebeck coefficient (S) were 1660 S·m−1 and 15.8 µV·K−1, respectively, which led to a power factor of 0.414 μW·m−1·K−2. Consequently, they have been utilized as the building block of a thermoelectric generator (TEG) device, which demonstrated a maximum power output (Pout) of 0.695 µW, with a power density (PD) of 372 nW·m−2, upon exposure to a temperature gradient of 60 K. The presented SWCNT-alkali-activated nanocomposites could establish the pathway towards waste thermal energy harvesting and future sustainable civil engineering structures.

The fluorescent ligand (L) based on the N2S2 pyridinophane macrocycle and the 7-nitrobenzo[1,2,5]oxadiazole (NBD) fluorogenic fragment has been synthesized to coordinate Pd(II) ions. Loaded on dye-doped silica nanoparticles, L can be used as a ratiometric fluorescent chemosensor for Pd(II) in water with high selectivity toward other metal ions including the platinum group ones.

Despite several types of fluorescent sensing molecules have been proposed and examined to signal Hg(2+) ion binding, the development of fluorescence-based devices for in-field Hg(2+) detection and screening in environmental and industrial samples is still a challenging task. Herein, we report the synthesis and characterization of three new coumarin-based fluorescent chemosensors featuring mixed thia/aza macrocyclic framework as receptors units, that is, ligands L1-L3. These probes revealed an OFF-ON selective response to the presence of Hg(2+) ions in MeCN/H2 O 4:1 (v/v), which allowed imaging of this metal ion in Cos-7 cells in vitro. Once included in silica core-polyethylene glycol (PEG) shell nanoparticles or supported on polyvinyl chloride (PVC)-based polymeric membranes, ligands L1-L3 can also selectively sense Hg(2+) ions in pure water. In particular we have developed an optical sensing array tacking advantage of the fluorescent properties of ligand L3 and based on the computer screen photo assisted technique (CSPT). In the device ligand L3 is dispersed into PVC membranes and it quantitatively responds to Hg(2+) ions in natural water samples.

We have recently developed an optimised synthetic strategy for the preparation of chemosensors based on the diaza-18- crown-6 hydroxyquinoline structure. This flexible approach allows to obtain a variety of substituted derivatives with improved fluorescence, metal ion binding, uptake and localisation properties. In this context, we have focused our attention on the design of specific chemosensors for intracellular Zn2? ions, because of their important role in many biological processes. Interestingly, among them one in particular shows the properties of making it a promising candidate for effective Zn(II) ions detection in biological environments. It presents, in fact, a very low toxicity, Zn2+/Mg2+ selectivity and a very large fluorescence enhancement on complexation.

We report here the synthesis of a new thio-aza macrocyclic chemosensor based on the 2,5-diphenyl[1,3,4]oxadiazole in which two thioether groups were inserted in a macrocycle with the aim to make it suitable for the coordination of soft and heavy metal ions. In acetonitrile solution, the fluorescence of the chemosensor changes upon addition of different metal ions, such as Cu(II), Zn(II), Cd(II), Pb(II), Hg(II) and Ag(I), that form a not fluorescent ML species and a fluorescent M2L species characterized also via NMR experiments. The hosting of the chemosensor inside the PluS Nanoparticles leads to a high water solubility, allowing to perform the metal detection without the use of additional solvents and also induced an higher selectivity towards Ag(I) and Hg(II). Moreover, it was demonstrated for the first time the possibility to control the stoichiometry of the formed complex upon changing the number of ligands per nanoparticles. To our opinion, this possibility can give an additional tool for the tuning of the affinity and selectivity of the chemosensor that could be of great interest for the design of more and more efficient systems.

none 9 no A systematic study of a series of diaza-18-crown-6 8-hydroxyquinoline (DCHQ) chemosensors, devoted to Mg(II) ion detection, was performed. Functionalization of DCHQ by peripheral substituents allowed the development of novel all-solid-state optodes via inclusion inside PVC-based polymeric films. The influence on the DCHQ-based optode response of the lipophilic sites functionalization and of the nature of the plasticizer, was investigated. Fluorimetric studies on optodes sensitivity towards a number of different metal cations (Ca2+, Na+, K+, Li+, Co2+, Cd2+, Pb2+, Cu2+, Hg2+, Zn2+) and NH4+were carried out. The results demonstrated the suitability of the DCHQ optodes to perform fast monitoring (

This work was devoted to the development of a new type of lipid-based (cubosome) theranostic nanoparticle able to simultaneously host camptothecin, a potent anticancer drug, and a squarain-based NIR-emitting fluorescent probe. Furthermore, to confer targeting abilities on these nanoparticles, they were dispersed using mixtures of Pluronic F108 and folate-conjugated Pluronic F108 in appropriate ratios. The physicochemical characterization, performed via SAXS, DLS, and cryo-TEM techniques, proved that aqueous dispersions of such cubosomes can be effectively prepared, while the photophysical characterization demonstrated that these nanoparticles may be used for in vivo imaging purposes. The superior ability of these innovative nanoparticles in targeting cancer cells was emphasized by investigating the lipid droplet alterations induced in He La cells upon exposure to targeted and nontargeted cubosomes.

The present study investigated the analytical capabilities of a new fluorescent chemosensor, named DCHQ5, a phenyl derivative belonging to the family of diaza-crown-hydroxyquinolines, for the quantitative assessment of total intracellular Mg content. The results obtained were compared to the analytical performances of DCHQ1 - the parent probe of the series which so far was the only suitable species for the quantitative assessment of the intracellular total magnesium and showed comparable results to atomic absorption spectroscopy. Different protocols were tested in several cell lines both by flow cytometry and by steady state fluorescence spectroscopy assays. The results obtained support the possibility to use DCHQ5 to accurately quantify the intracellular total Mg in much smaller samples than DCHQ1, also displaying an increased stable intracellular staining. These features, combined with the high fluorescence enhancement upon cation binding, and the possibility to be excited both in the UV and visible region, make DCHQ5 a valuable and versatile analytical tool for Mg assessment in biological samples.

none 7 no The quinoline urea derivatives 1,3-di(quinolin-5-yl) urea (DQ5U), 1-phenyl-3-(quinolin-6-yl) urea (PQ6U), 1-(isoquinolin-5-yl)-3-phenylurea (PiQ5U) and 1-phenyl-3-(3,5-bis(pyrid-2-yl)-1,2,4-triazol-4-yl) urea (PPT4U) have been synthesised and structurally characterized by powder and single crystal X-ray diffraction. Their gelator behaviour in the formation of Ag-complexes has been explored. Compound DQ5U proved capable of gelating the mixed solvent EtOH-DMF 1:2 (v/v) when mixed with 1 equivalent of AgNO3. In the case of PQ6U, two polymorphic forms of the complex [Ag(PQ6U)(2)]NO3, plus the solvated form [Ag(PQ6U)(2)]NO3 center dot CH3CN, were crystallized. Photophysical characterization of the ligands has been conducted in solution, while fluorescence microscopy has been used to examine the microstructure and photophysical properties of the gels formed by PQ5U and DQ5U with AgNO3. Dario Braga;Simone d'Agostino;Eros D'Amen;Fabrizia Grepioni;Damiano Genovese;Luca Prodi;Massimo Sgarzi Dario Braga;Simone d'Agostino;Eros D'Amen;Fabrizia Grepioni;Damiano Genovese;Luca Prodi;Massimo Sgarzi

A new turn-on Cu2+ fluorescent sensor (CST) having a trehalose moiety, which confers a relatively large solubility in water, has been synthesized. The chemosensor is therefore suitable for studies in aqueous solution. Full potentiometric and UV-vis characterization evidence that at physiological pH CST forms with Cu2+ a species with a 1 : 1 stoichiometry allowing for a straightforward correlation between CST response and copper(II) concentration. The presence of the trehalose unit does not negatively affect the selectivity of CST for Cu2+ over a series of metal ions of interest as proven by fluorescence measurements. The novel chemosensor, tested in differentiated neuroblastoma SH-SY5Y cells, is able to detect Cu2+ in the extracellular region, as well as to track copper transfer processes upon cell stimulation induced by cellular depolarization.

Although magnesium is essential for a number of biological processes crucial for cell life, its distribution and intracellular compartmentalization have not been thoroughly elucidated yet, mainly because of the inadequacy of the available techniques to map intracellular magnesium distribution. For this reason, particular interest has been recently raised by a family of fluorescent molecules, diaza-18-crown-6 8-hydroxyquinolines (DCHQ1 and its derivatives), that show a remarkable affinity and specificity for magnesium, higher than all the commercially available probes, thus permitting the detection of the total intracellular magnesium. A recently optimized synthetic approach to DCHQ using microwave heating allowed us to easily generate a variety of substituted DCHQ derivatives with improved fluorescence, uptake and selective localization with respect to the original reference material (DCHQ1). The introduction of aromatic side groups enhanced the fluorescence response in cells and also improved intracellular uptake and retention of the probes even after washing. Enhanced uptake has also been achieved with an acetoxymethyl ester derivative that is recognized by the intracellular esterases. Finally, the insertion of two long hydrophobic side chains allowed a better staining of the membranes due to the high affinity to the lipophilic environment. These results show the potential of these new fluorescent probes as effective tools for shedding light on total intracellular magnesium distribution and homeostasis.

This review aims to give an overview on the state of the art in the precise context of metal complexes-based ECL dyes directly adsorbed on, included in or interacting with nanoparticles of various nature. Electrogenerated chemiluminescence, or electrochemiluminescence (ECL), is the process through which species generated at electrodes undergo homogeneous high-energy electron transfer reactions to give excited states that emit light. When stable ECL probes such as ruthenium coordination complexes are used, this process can be performed several times, free of the interferences typical of photoluminescence such as the excitation light, providing a clear and stable signal suitable for highly sensitive assays. The ECL emission is initiated and controlled by the electrode potential and immobilization of the ECL probes on the electrode surface allows one to reduce the consumption of expensive reagents, simplifies the experimental design, and creates regenerable sensing devices. The organization of the electrode surface is thus the key point to optimize the device performance. Nanoparticles have proved their potential as tools to organize the ECL probes, to increase the active area and to improve the electrochemical properties of the interface. There is an extended research devoted on one hand to optimize the materials, and on the other hand to explore the wide horizon of possibilities that arise from the combination of nanoparticles and ECL probes, co-reagents, (bio)markers and other functional moieties. The results discussed in this review clearly show that the use of nanoparticles aimed to obtain signal enhancement represents one of the most interesting research lines for the development of the ECL technique. The activity in this field is so dynamic that outstanding results could reasonably be expected in the near future.

The field of nanoparticles is amazingly many-sided and consequently their applications range between many different areas from industry to bio-analysis and catalysis. In particular, luminescent nanoparticles attract close attention in the areas of biology, medical diagnosis and therapy, where they already find many applications. In this so fascinating and wide framework we have focussed our attention on luminescent silica nanoparticles able to act as sensing materials. We highlight here the importance, especially with the aim of sensing, of gaining precise knowledge and control of their structures; the performance of a chemosensor is, in fact, totally dependent on its design. We then briefly present the state of the art and the progress both in the synthetic protocols and in the application of luminescent silica nanoparticles as chemosensors. We present many recent examples, organized into two main sections, the first dealing with systems presenting the signalling units on the surface (dye coated silica nanoparticles, DCSNs) and the second with systems entrapping the dyes inside the silica matrix (dye doped silica nanoparticles, DDSNs).

The field of nanoparticles is amazingly many-sided and consequently their applications range between many different areas from industry to bio-analysis and catalysis. In particular, luminescent nanoparticles attract close attention in the areas of biology, medical diagnosis and therapy, where they already find many applications. In this so fascinating and wide framework we have focussed our attention on luminescent silica nanoparticles able to act as sensing materials. We highlight here the importance, especially with the aim of sensing, of gaining precise knowledge and control of their structures; the performance of a chemosensor is, in fact, totally dependent on its design. We then briefly present the state of the art and the progress both in the synthetic protocols and in the application of luminescent silica nanoparticles as chemosensors. We present many recent examples, organized into two main sections, the first dealing with systems presenting the signalling units on the surface (dye coated silica nanoparticles, DCSNs) and the second with systems entrapping the dyes inside the silica matrix (dye doped silica nanoparticles, DDSNs).

The design of fluorescent chemosensors for biologicallyrelevant chemical species has important impacts in many ap-plications, and for this reason it has been the subject ofactive research in many laboratories worldwide. The ach-ievements in this wide research topic have promoted enor-mous steps forwards, for example, in the field of cell biology,thanks to the comprehension of the role of different chemi-cal species in many biological processes. Recently, research-ers have been moving from molecular chemosensors basedon two communicating units, a receptor and a dye, towardmore complex and sophisticated structures, and have triedto push further the limits of sensitivity and selectivity. Manydifferent solutions have been proposed but, among them,sensing systems based on nanoparticles are certainly one ofthe most interesting and promising.

N,N′-Bis-((8-hydroxy-7-quinolinyl)methyl)-1,10-diaza-18-crown-6 ether 1a and its analogue 1c are known as fluorescent sensors of magnesium in living cells. With the aim to investigate the effects of the substitution pattern on the photophysical properties of ligands 1 and their metal complexes, we developed an efficient microwaves enhanced one-pot Mannich reaction to double-armed diaza-crown ligands 1 carrying a variety of substituents. This new protocol is characterized by shorter reaction times, enhanced yields, and improved product purities with respect to the use of conventional conductive heating.

The photocatalytic degradation of the wastewater dye pollutant methylene blue (MB) at ZnO nanostructured porous thin films, deposited by direct current reactive magnetron sputtering on Si substrates, was studied. It was observed that over 4 photocatalytic cycles (0.3 mg · l−1 MB solution, 540 minUV irradiation), the rate constant k of MB degradation decreased by ∼50%, varying in the range (1.54 ÷ 0.78) · 10–9 (mol·l−1·min−1). For a deeper analysis of the photodegradation mechanism, detailed information on the nanostructured ZnO surface morphology and local surface and subsurface chemistry (nonstoichiometry) were obtained by using scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) as complementary analytical methods. The SEM studies revealed that at the surface of the nanostructured ZnO thin films a coral reef structure containing polycrystalline coral dendrites is present, and that, after the photocatalytic experiments, the sizes of individual crystallites increased, varying in the range 43 ÷ 76 nm for the longer axis, and in the range 28 ÷ 58 nm for the shorter axis. In turn, the XPS studies showed a slight non-stoichiometry, mainly defined by the relative [O]/[Zn] concentration of ca. 1.4, whereas [C]/[Zn] was ca. 1.2, both before and after the photocatalytic experiments. This phenomenon was directly related to the presence of superficial ZnO lattice oxygen atoms that can participate in the oxidation of the adsorbed MB molecules, as well as to the presence of surface hydroxyl groups acting as hole-acceptors to produce OH· radicals, which can be responsible for the generation of superoxide ions. In addition, after experiments, the XPS measurements revealed the presence of carboxyl and carbonyl functional groups, ascribable to the oxidation by-products formed during the photodegradation of MB.