A new series of D-?-A (TKB1-TKB3) structural chromophores with various electron donor units were designed, synthesized, and fully characterized. Their photophysical properties and cytotoxicity were investigated, and practical applications evaluated by fluorescence imaging in living cells. A direct dependence of the optical properties on the electron donor groups has been revealed for all the samples. To this purpose, time-dependent density functional theory calculations were conducted. Finally, dyes showed high biocompatibility, long-term retention and low cytotoxicity in different cell-lines including neuroblastoma cell (SH-SY5).

Three new metal-free organic dyes with the [1]benzothieno[3,2-b]benzothiophene (BTBT) ?-bridge, having thestructure donor-?-acceptor (D-?-A) and labeled as 19, 20 and 21, have been designed and synthesized for application in dyesensitizedsolar cells (DSSC). Once the design of the ?-acceptor block was fixed, containing the BTBT as the ?-bridge and thecyanoacrylic group as the electron acceptor and anchoring unit, we selected three donor units with different electron-donorcapacity, in order to assemble new chromophores with high molar extinction coefficients (?), whose absorption features wellreflect the good performance of the final DSSC devices. Starting with the 19 dye, which shows a molar extinction coefficient ? ofover 14,000 M-1 cm-1 and takes into account the absorption maximun at the longer wavelength, the substitution of the BFTdonor unit with the BFA yields a great enhancement of absorptivity (molar extinction coefficient ? > 42,000 M-1 cm-1), untilreaching the higher value (? > 69,000 M-1 cm-1) with the BFPhz donor unit. The good general photovoltaic performancesobtained with the three dyes highlight the suitable properties of electron-transport of the BTBT as the ?-bridge in organicchromophore for DSSC, making this very cheap and easy to synthesize molecule particularly attractive for efficient and low-costphotovoltaic devices

Three fluorenone-derived two-photon fluorescent probes (TK) targeting the lysosomes (TK-Lyso) and mitochondria (TK-Mito1 and TK-Mito2) were synthesized by introducing different diphenylamine moieties into the fluorenone core. The TK dyes showed high biocompatibility and long-term retention, low cytotoxicity, large Stokes shift and good fluorescence quantum yield. The results of the present work disclose a class of organic dyes with potential wide applications as specific and efficient probes for lysosomes and mitochondria in the study of various biological processes.

A high-yield synthesis of pure anatase titania nanorods has been achieved through a nonaqueous microwave-based approach. The residual organics on nanoparticles surfaces were completely removed under ozone flow at room temperature in air. The TiO2 nanorods, with average lengths of 27.6 +/- 5.8 nm and average diameters of 3.2 +/- 0.4 nm, were characterized by powder X-Ray diffraction, transmission electron microscopy, selected area diffraction, BET surface area analysis and FT-IR spectroscopy. The photocatalytic performances of the as-synthesized TiO2 nanorods and platinum loaded TiO2 nanorods were implemented with respect to both commercial P25 and platinum loaded P25. Performance enhancements should be attributed to effects like differences in the adsorption capacity and in the separation efficiency of the photogenerated electrons-holes.

High-yield, rapid and facile synthesis of elongated pure anatase titania nanoparticles has been achieved through a nonaqueous microwave-based approach. The residual organics onto nanoparticles surfaces were completely removed through a new treatment under ozone flow, at room temperature in air. Such an ozone cleaning method revealed an effective inexpensive dry process of removing organic contaminants from nanoparticles surfaces. The TiO<inf>2</inf> elongated nanoparticles having a length of 13.8 ± 5.5 nm and a diameter of 9.0 ±1.2 nm were characterized by powder X-Ray diffraction, transmission electron microscopy, selected area diffraction, BET surface area analyzer and FT-IR spectroscopy. Photocatalytic evaluation demonstrated that the as-synthesized ozone-cleaned TiO<inf>2</inf> nanoparticles and TiO<inf>2</inf> nanoparticles loaded with platinum possess excellent Rhodamine B performance with respect to both commercial spherical nanotitania P25 and P25 loaded with platinum. This could be attributed to the anatase phase purity, small size, large specific surface area and clean surfaces of the prepared nanoparticles.

In this work, we investigate the optical and structural properties of the well-known triplet emitter bis(4?,6?-difluorophenylpyridinato)-iridium(III) picolinate (FIrpic), showing that its ability to pack in two different ordered crystal structures promotes attractive photophysical properties that are useful for solid-state lighting applications. This approach allows the detrimental effects of the nonradiative pathways on the luminescence performance in highly concentrated organic active materials to be weakened. The remarkable electro-optical behavior of sky-blue phosphorescent organic light-emitting diodes incorporating crystal domains of FIrpic, dispersed into an appropriate matrix as an active layer, has also been reported as well as the X-ray diffraction, nuclear magnetic resonance, electro-ionization mass spectrometry, and scanning electron microscopy analyses of the crystalline samples. We consider this result as a crucial starting point for further research aimed at the use of a crystal triplet emitter in optoelectronic devices to overcome the long-standing issue of luminescence self-quenching.

Hybrid inorganic/organic core/shell nanoparticles were prepared through a two step synthesis procedure. In the first step, pure anatase TiO2 nanoparticles were synthesized though a rapid microwave assisted non-aqueous route. Then, the obtained titania nanoparticles were coated with polyvinyl alcohol (PVA) using a simple solution method followed by relatively low temperature treatment.The PVA-coated titania nanoparticles samples were prepared at different TiO2-PVA weight ratio and they were characterized using X-Ray diffraction, transmission electron microscopy, infrared spectroscopy and Brunauer-Emmett-Teller (BET) analysis.Photocatalytic performance was also evaluated for all samples and the results indicated that TiO2:PVA weight ratio was a key factor to obtain an improvement of the photocatalytic activity with respect to bare TiO2 nanoparticles, since PVA concentration influenced the surface area and the aggregation of nanoparticles and the thickness of the coating layer. This inexpensive system provides a simple, quick and effective approach which allows to obtain core/shell hybrid nanostructures.

Novel triphenylamine (TPA)-based organic dyes were synthesized and assessed for their performance in dye-sensitized solar cells (DSSCs). In the dyes considered the TPA group and the cyanoacetic acid have the role of electron-donor and -acceptor, respectively, whereas a thienyl-fluoro-phenyl-substituted was introduced as ?-linker to improve the dye performance in DSSCs. Experimental characterizations empasize that the presence of electron withdrawing substituents in the linker close to the electron-acceptor moiety leads to a more efficient intramolecular photoinduced charge transfer. In fact, photovoltaic experiments reveal that the DSSCs based on the thienyl-o-fluoro-phenyl substituted dyes yield a better solar-energy-to-electricity conversion efficiency.

We here report the implementation of poly[(3-N-methylimidazoliumpropyl) methylsiloxane-co-dimethylsiloxane]iodides as suitable polymeric hosts for a novel class of in situ cross-linkable iodine/iodide-based gel-electrolytes for dye-sensitized solar cells. The polymers are first partially quaternized and then subjected to a thermal cross-linking which allows the formation of a 3D polymeric network which is accompanied by a dramatic enhancement of the ionic conductivity.

An efficient microwave-assisted synthesis of TiO2:(B) nanorods, using titanium tetraisopropoxide (TTIP), benzyl alcohol as the solvent, together with boric acid and oleic acid as the additive reagents, has been developed. Chemical modification of TTIP by oleic acid was demonstrated as a rational strategy to tune the shape of TiO2 nanocrystals toward nanorod formation. The differently-shaped TiO2:(B) nanocrystals were characterized in detail by transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and nitrogen absorption-desorption. Oleic acid coordinated on the nanocrystal surface was removed by the reduction of its carboxyl group, and the photocatalytic activity of bare TiO2 nanocrystals, under visible light irradiation, was also evaluated. The synthesized TiO2 anatase nanorods exhibited a good photoactivity and completely degraded Rhodamine B solution within three hours.

Three novel organic dyes, coded TK1, TK2 and TK3, incorporating two donor moieties, cyanoacrylic acid as an acceptor/anchoring group, the dibenzofulvene core and an oligothiophene spacer in a 2D-pi-A system, were designed, synthesized, and successfully utilized in dye-sensitized solar cells. The dye TK3, containing two thiophene rings as spacers, shows an IPCE action spectrum with a high plateau from 390 nm to 600 nm, increased open-circuit photovoltage by 40 mV and short-circuit photocurrent by 7.03 mA cm(-1), with respect to TK1. Using CDCA as the co-adsorbent material, the J(sc) of TK3 was increased to 14.98 mA cm (1) and a strong enhancement in the overall conversion efficiency (7.45%) was realized by TK3 compared to TK1 (1.08%), in liquid electrolyte-based DSSCs.

The photodynamic activity occurring through the lysosome photo-damage is effective in terms of triggered synergiceffectswhich can avoid chemo-resistance pathways. The potential photodynamic activity of twofluorescentlysosome-specific probes was studied providing their interaction with human serum albumin, demonstratingtheir in vitro generation of singlet oxygen and investigating the resulted photo-toxic effect in human cancer cells.

Three new 2DepeA dyes (TK4, TK5 and TK6), composed of diarylamine donor groups, a dibenzofulvenethiophenecore as the p-bridge, and a cyanoacrylic acid anchoring group as the acceptor, have beensuccessfully designed, synthesized, and characterized both experimentally and computationally. Theperformance in DSSC solar cells has been also studied. Octyloxy chains were introduced on the backboneof the dye, in order to increase donor capability, avoid aggregation side effects and increase physicalinsulation between electrolyte system and the TiO2 layer. The dye containing the octyloxy chains on thedonor group and two thiophene ring as an extension of p-bridge showed the best photovoltaic performancewith a maximum of solar energy-to-electricity conversion yield of 7.8% under AM 1.5 irradiation(100 mW/cm2).

Three novel 2D-p-A metal-free organic dyes TK 7e9 containing a dibenzofulvene (DBF) linked to twothiophene units as the p-bridge, diarylamines with and without alkoxy chains as donor groups and thecyanoacrylic acid moiety as the acceptor and anchoring group were synthesized. The new dyes TK werecharacterized by optical and electrochemical measurements and density functional theory calculationsand were used as sensitizers in liquid dye-sensitized solar cells. The effects of alkoxy-functionalization ofdonor moiety and of hexyl chain insertion onto one thienyl ring of p-linker on dye properties andperformances were investigated. The results discover the dye TK7, bearing two simple diphenylaminegroups without alkoxy chains, exhibits the best behavior in terms of light absorption and cell performance(PCE of 7.9% and photovoltaic parameters of Jsc of 17.82 mA cm
2, Voc of 670 mV and FF of 0.66).Lower power conversion efficiencies of 6.3% and 6.1% were found for TK8 and TK9, respectively, asa consequence of the presence of the alkoxy chains.

The present investigation reported the synthesis of ultrafine anatase titanium dioxide (TiO2) nanocrystals using titanium isopropoxide (TTIP) as precursor in presence of benzyl alcohol as solvent and glucose as capping agent via a microwave-solvothermal method. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption, micro Raman and Fourier transform infrared spectroscopies (FT-IR). From this preparation method it was demonstrated that the obtainable TiO2 nanocrystals were less than 10 nm in mean size, mainly in anatase phase, presenting also a mesoporous structure. The use of glucose as capping agent added in the reaction system played a role in the anisotropic growth of the TiO2 nanocrystals, as evidenced by XRD domain size analysis and promoted an increase of the specific surface area.

The synthesis of thiophene fluorophores (TFs) and the engineering of molecular structure to achieve bright and stable blue to red and white fluorescence are described. Examples of application of TFs in cellular studies are reported. Copyright © Taylor and Francis Group, LLC.

Selective imaging of lysosomes by fluorescence microscopy using specific fluorescent probes allows the study of biological processes and it is potentially useful also for diagnosis. Lysosomes are involved in numerous physiological processes, such as bone and tissue remodeling, plasma membrane repair, and cholesterol homeostasis, along with cell death and cell signaling. Despite the great number of dyes available today on the market, the search for new fluorescent dyes easily up-taken by cells, biocompatible and bearing bright and long-lasting fluorescence is still a priority. Methods: Two thiophene-based fluorescent dyes, TC1 and TC2, were synthetized as lysosome-specific probes. Results: The new dyes showed high selectivity for fluorescent staining and imaging of lysosomes and disclosed high photostability, low toxicity and pH insensitivity in the range 2-10. Conclusions: The TC dyes exhibited high co-localization coefficients (>95%) and moderate quantum yields. They showed high biocompatibility and long-term retention, important features for biological applications. General significance: The results of the present work disclose a new class of organic dyes with potential wide applications as specific and efficient lysosome probes in the study of various biological processes.