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ZnSO(3) microrods with uniform size and shape can be prepared under microwave irradiation at much higher speed than a conventional heating bath, usually in minutes. The annealing of ZnSO(3) microrods produced porous ZnO microrods with pore size between 50-200 nm.

Both photoswitchable fluorescent nanoparticles and photoactivatable fluorescent proteins have been used for super-resolution far-field imaging on the nanometer scale, but the photoactivating wavelength for such photochemical events generally falls in the near-UV (NUV) region (

A low cost and environmentally benign process for tetrabutyl titanate-controlled ring-opening polymerization of epsilon-caprolactone at ambient temperature of 10-40 degrees C is introduced affording poly(epsilon-caprolactone) with pre-designed molecular weights and narrow molecular weight distribution.

High-concentration gold nanoparticles stabilized by poly(vinylpyrrolindone) (PVP) are prepared through modified citrate-reduction method. The modified approach possesses all the advantages of the popular citrate reduction method. With PVP as weak ligands as well as spatial effects for the metal nanoparticles, the control of the size and size distribution of the gold nanoparticles in the size range between 10 and 30 nm was achieved via maintaining balanced nucleation and growth by tuning the feed ratios of the metal precursors and reducing reagents. As a modified procedure to gold nanoparticles, PVP-stabilized gold nanoparticles are more stable in a broad range of pH and different buffers than conventional gold colloids. Because only PVP are employed in the new synthetic schemes, surface modification and functionalization of the resulting gold nanoparticles through small molecular ligands can be readily carried out.

Recently, semiconductor nanocrystals or quantum dots (QDs) aroused great concern because of their unique properties such as the size-dependent photoluminescence. They have many excellent applications in areas of molecular bioimaging, medical detection and even energy, especially as biosensing and imaging instead of fluorescent dyes. For the bio-safety, however, we should assess the cytotoxicity of QDs before used in biomedical imaging. Here, the cytotoxicity of amino-functionalized CdSe/CdS (CdSe/CdS-NH2) QDs and carboxy-functionalized CdSe/CdS (CdSe/CdS-COOH) QDs was investigated by MTT assay method. According to our findings, both CdSe/CdS-NH2 and CdSe/CdS-COOH have a dose-dependent effect on cell proliferation. The cytotoxicity of QDs varies with storing time of QDs and kinds of cells. The cytotoxicity of QDs modified with -COOH or -NH2 groups both vary with concentrations in positive linear or change with QD storing time in negative linear. The results indicate that CdSe/CdS-COOH QDs have lower toxicity than CdSe/CdS-NH2 QDs. Hela cell is somewhat more sensitive to amino- and carboxy-modified QDs than Bel7404 cell for MTT assays.

A novel interconnected cylindrical micellar network was prepared from a diblock copolymer, poly(maleic anhydride- alt -styrene)- b -polystyrene, in ethanol under a self-assembly directing agent: Zn 2+ ions. The solution containing interconnected cylindrical network is bluish and transparent, which is stable for more than 6 months at room conditions without any observable macroscopic phase separation. In aqueous solution, however, hydrolysis of the anhydride yields hydrophilic carboxyl groups, which result in formation of uniform positive spherical micelles from the same diblock polymer. The nanostructures of both the spherical micelles and cylindrical assemblies are characterized with light scattering and transmission electron microscopy (TEM).

Large-scale synthesis of semiconductor nanocrystals or quantum dots (QDs) with high concentration and high yield through simultaneously increasing the precursor concentration was introduced. This synthetic route conducted in diesel has produced gram-scale CdSe semiconductor quantum dots (In optimal scale-up synthetic condition, the one-pot yield of QDs is up to 9.6g). The reaction has been conducted in open air and at relatively low temperature at 190-230 degrees C in the absence of expensive organic phosphine ligands, aliphatic amine and octadecene, which is really green chemistry without high energy cost for high temperature reaction and unessential toxic chemicals except for Cd, which is the essential building block for QDs.

In this phantom-based study, we assessed the imaging potential of lead sulfide (PbS) near-infrared quantum dots (QDs) as novel contrast agents for deep tissue fluorescence imaging applications.

Quantum dots (QD) of a CdSe-ZnS core-shell structure are coated with silica spheres to improve their stability in biological buffers and biocompatibility in fluorescence imaging. We found that it was critical to transfer quantum dots from organic phase to aqueous phase before the silica shell growth process. As a result, high quality CdSe-ZnS-SiO2 core-shell-shell nanoparticles were prepared in high yields and their size and distribution are characterized with transmission electron microscopy and dynamic light scattering, which yielded uniform sizes and narrow polydispersity. Single particle fluorescence spectroscopy on the silica-protected quantum dots showed they were stronger emitters with consistent fluorescence intensity and "on-off" behaviors than bare CdSe-ZnS nanocrystals.

Optically switchable dual-color fluorescent nanoparticles that incorporate two classes of dyes into the polymeric chains have been synthesized using an emulsion polymerization method. The nanoparticles consist of an organic photoisomerizable dye, spiropyran, as an optically responsive component and another fluorescent dye, perylene diimide, as a high-energy emitter. Under UV irradiation, the colorless spiropyran undergoes photoisomerization to yield merocyanine, which absorbs at 588 nm and fluoresces strongly at 670 nm. The absorption band of the merocyanine matches well the fluorescence bands of perylene diimide (at 535 and 575 nm), and therefore fluorescence resonance energy transfer (FRET) converts the high-energy green emission of the perylene into low-energy red emission when the merocyanine form is present. Upon exposure to alternating UV ( 420 nm) light, the nanoparticles cycle between red and green fluorescence as the spiro and mero forms of the optically responsive component...

Short interfering RNAs (siRNAs) have become a mainstream tool reliably used to study and silence protein expression. We offer a proof-of-principle demonstration that siRNAs may be modified into a siRNA-based molecular beacon that activates upon binding to sequence-specific mRNA in cells while mediating RNA interference. We successfully demonstrate detection and knockdown of telomerase expression in human breast cancer cells. This probe provides a novel look at siRNA target validation that is not currently possible in live cells and holds promising potential in biological applications for disease detection and therapy based on mRNA expression, such as a telomerase-targeted siRNA probe in cancer.

Flexible fiber-shaped supercapacitors have shown great potential in portable and wearable electronics. However, small specific capacitance and low operating voltage limit the practical application of fiber-shaped supercapacitors in high energy density devices. Herein, direct growth of ultrathin MnO2 nanosheet arrays on conductive carbon fibers with robust adhesion is exhibited, which exhibit a high specific capacitance of 634.5 F g−1 at a current density of 2.5 A g−1 and possess superior cycle stability. When MnO2 nanosheet arrays on carbon fibers and graphene on carbon fibers are used as a positive electrode and a negative electrode, respectively, in an all-solid-state asymmetric supercapacitor (ASC), the ASC displays a high specific capacitance of 87.1 F g−1 and an exceptional energy density of 27.2 Wh kg−1. In addition, its capacitance retention reaches 95.2% over 3000 cycles, representing the excellent cyclic ability. The flexibility and mechanical stability of these ASCs are highlighted by the negligible degradation of their electrochemical performance even under severely bending states. Impressively, as-prepared fiber-shaped ASCs could successfully power a photodetector based on CdS nanowires without applying any external bias voltage. The excellent performance of all-solid-state ASCs opens up new opportunity for development of wearable and self-powered nanodevices in near future.

Emulsion polymerization yields 40–400 nm diameter polymer nanoparticles with spiropyran-merocyanine dyes incorporated into their hydrophobic cavities; in contrast to their virtually nonfluorescent character in most environments, the merocyanine forms of the encapsulated dyes are highly fluorescent. Spiro-mero photoisomerization is reversible, allowing the fluorescence to be switched “on” and “off” by alternating UV and visible light. Immobilizing the dye inside hydrophobic pockets of nanoparticles also improves its photostability, rendering it more resistant than the same dyes in solution to fatigue effects arising from photochemical switching. The photophysical characteristics of the encapsulated fluorophores differ dramatically from those of the same species in solution, making nanoparticle-protected hydrophobic fluorophores attractive materials for potential applications such as optical data storage and switching and biological fluorescent labeling. To evaluate the potential for biological tagging, these optically addressable nanoparticles have been delivered into living cells and imaged with a liquid nitrogen cooled CCD.

Thermosensitive gold nanoparticles were fabricated by conjugating Au with a thiol-terminated poly(N-isopropylacrylamide) or PPA; this polymer stabilizer exhibits a temperature transition while undergoing a hydrophilic to hydrophobic transformation. The introduction of PPA onto gold nanoparticles has sensitized Au nanoparticles with unique temperature dependence. At low temperature (25 degrees C), the solutions containing PPA-functionalized gold nanoparticles are transparent, whereas higher temperatures (30 degrees C) lead to opaque suspensions. The thermosensitive property of PPA-functionalized Au nanoparticles is reversible, and the clear-opaque suspensions can be repeated many times.

All-optical modulation of a spiropyran-based device, integrating the transmittance switching (absorption) and wavelength modulation (emission) of visible light frequency induced by alternating UV/visible light irradiation is demonstrated. As an alternative to conventional organic transistors, all-optical devices based on SP-PCL have potential utility as single molecular transistors for optical switching and visible wavelength modulation.

Methods 20 SRS cases diagnosed in Beijing Children’s Hospital from 2006 to 2011 were studied retrospectively for clinical manifestations, physical signs, laboratory examinations and respond of GH treatment. We compared with 3 different diagnostic criteria and used the methylationspecific multiplex ligation dependent probe amplification (MS-MLPA) method to detect the chromosome 11p15 imprinting defects in 16 patients of them, meanwhile take 10 normal control.

The optical properties and piezofluorochromic behaviour of N,N′-dioctyl-1,7-di(4-(1,2,2-triphenyl)vinyl)phenyl-3,4:9,10-tetracarboxylic perylenebisimide (PBI–TPE) have been investigated. PBI–TPE shows strong fluorescence in non-polar solvents, in contrast to complete quenching in common moderately polar to polar solvents, most likely due to intramolecular charge transfer (ICT) from the donating tetraphenylethene (TPE) groups to the acceptor perylenebisimide core. The solid-state fluorescence is morphology dependent, in which the amorphous-state displays near infra-red emission at 744 nm and the crystalline state shows a blue-shift in emission at 665 nm with a difference of 79 nm. Crystalline PBI–TPE exhibits stress induced amorphisation resulting in a piezo-responsive behaviour in which the metastable amorphous state and crystalline state can be interconverted by grinding and thermal annealing (200 °C)/recrystallisation. This reciprocal conversion gives rise to the piezofluorochromic effect. Finally, crystalline microstructures were used to fabricate a microwire field-effect transistor (MFET) with the effective mobility (μe) and capacitance (Ci) estimated to be 3.11 × 10−5 cm2 V−1 s−1 and 1.51 × 10−15 F, respectively.

Phenanthroline–tetraphenylethene (Phen–1TPE) was synthesized by a typical Suzuki coupling. The aggregation-induced emission (AIE) properties and interactions with metal ions in THF–water (fw = 90%) and in THF were investigated. Aggregation-induced emission logic gates were fabricated based on the metal ion sensing of Phen–1TPE conjugates via control of the metal ions and solvents. In THF–water with fw = 90%, Phen–1TPE exhibits a strong AIE effect, while the fluorescence is almost totally quenched upon the addition of Cu2+ compared to other metal ions. Phen–1TPE works as an “INHIBIT” logic gate, with Cu2+ and aggregation (“Agg”) as the inputs and the fluorescence as the output. The fluorescence can also be quenched in fw = 90% by the addition of metal ions (Cd2+, Zn2+, Sn2+ and In3+). In THF, Phen–1TPE exhibits a metal ion–ligand charge transfer (MLCT)-caused fluorescence enhancement by the addition of metal ions (Cd2+, Zn2+, Sn2+ and In3+). Thus it is established that Phen–1TPE works as a dual “XOR” logic gate with metal ions (Cd2+, Zn2+, Sn2+ and In3+) and “Agg” as the inputs. The INHIBIT and XOR logic gates were manipulated by utilizing different metal ions and water–THF volume ratios as the inputs, and the fluorescence of Phen–1TPE as the output.

* E-mail: mqzhu@hust.edu.cn Received October 8, 2012; revised December 5, 2012; published online December 20, 2012. Project supported by the National Basic Research Program of China (No. 2013CB922104), the National Natural Science Foundation of China (Nos. 20874025, 21174045), the National Natural Science Foundation of China Research Fellowship for International Young Scientists (No. 21150110141), the China Postdoctoral Science Foundation (No. 20100480065), the Open Program for Beijing National Laboratory for Molecular Sciences (BNLMS) and the Special Financial Grant from the China Postdoctoral Science Foundation (No. 2012T50642). 国家基础研究计划 (No. 2013CB922104)、国家自然科学基金 (Nos. 20874025, 21174045)、国家自然科学基金委外国青年学者研究基金 (No. 21150110141)、中国博士后科学基金(No. 20100480065)和中国博士后特别资助基金(No. 2012T50642)资助项目.

We report the synthesis of novel amorphous fluorene-based fluorophores that have been end-capped with tetraphenylethene (TPE). Although in the solid state the fluorophores show bright cyan fluorescence with high (68%) photoluminescence quantum efficiency (PLQE), strong fluorescence quenching is observed in solution with low PLQE values ranging from 0.3% to 2.1%. When the fluorophores were added to a 90% water–THF solvent mixture nanoparticles were formed, which was confirmed by Dynamic Light Scattering (DLS) and Atomic Force Microscopy (AFM). Subsequent fluorescence measurements reveal that all the fluorophores exhibit aggregation induced emission (AIE) with high PLQE (41%). We have carried out a comparative study of 5 fluorene-based TPE materials (F(1–5)TPE), in which the fluorene core is extended, and investigated their thermal, optical, electrochemical and electroluminescence properties. From fluorescence quantum yield data we have discovered that the AIE effect decreases as the fluorene core increases both in the nanoparticle and in the solid state. Thermal analysis reveals that all fluorophores are amorphous with high thermal stabilities. Potential application in solid state vapour sensing has been demonstrated using dichloromethane that shows “on” and “off” fluorescence behaviour. Finally, Organic Light Emitting Diodes (OLEDs) have been fabricated with device configuration ITO/PEDOT/F(1–5)TPE/TPBi/LiF/Al. The best OLED device that incorporates F1-TPE as the emitter exhibits a turn-on voltage of 5.8 V, Lmax = 1300 cd m−2, ηP,max = 1 lm W−1 and ηC,max = 2.6 cd A−1.

In recent years low molecular weight carbazole-based materials have attracted much interest as hole-transporting and host materials for organic light emitting diode (OLED) applications. Herein we report the tri- and tetra-bromination of carbazole and the subsequent synthesis of novel carbazole oligomers substituted at the 1- and 8-positions. The oligomer series range from mono-carbazole (Cz-1) to quinque-carbazole (Cz-5) and we have carried out a comparative study of their thermal, optical, electrochemical and optoelectronic properties. The glass transition temperature increases as the carbazole core is enlarged (0 °C to 54 °C) and all oligomers exhibit excellent thermal stability with high thermal decomposition temperatures in the range of 442 °C to 494 °C. From optical data and Raman spectroscopy we observe negligible changes in the effective conjugation length as the number of peripheral carbazole units increases. However, the oxidation potential decreases as the number of carbazole units increase, in which Cz-5 exhibits the highest HOMO level (−5.19 eV) compared to other carbazole oligomers in the series. All carbazole materials emit deep blue photoluminescence ranging from 416 to 432 nm in the solid-state. Finally, electrophosphorescence was demonstrated from solution processable guest-host organic light- emitting diodes (OLEDs) fabricated using Cz(2–5) as the host materials with device configuration ITO/PEDOT/Cz1–5 : 10% Ir(mppy)3/TPBi/LiF/Al. The device efficiency decreases from Cz-3 to Cz-5. The best OLED device that incorporates Cz-3 as the host exhibits a turn-on voltage of 2.8 V, maximum brightness of 2310 cd m−2, maximum power efficiency of 33.6 lm W−1, maximum current efficiency 35.5 cd A−1 and EQE of 10.6%.

A unique synthesis of a well-defined block copolymer having alternating maleic anhydride(MAn)/styrene(St) segments and PSt segments was achieved via radical addition–fragmentation chain transfer (RAFT) copolymerization and the self-assembly aggregating behavior of its hydrolyzed amphiphilic product in water was demonstrated.

Background Due to the depletion of fossil resources and their environmental impact, woody biomass has received much attention as an alternative resource. Lignin, as the third most abundant biopolymer from biomass, is now considered as an excellent alternative feedstock for chemicals and materials. The conversion of lignin to the value-added products is a key process to achieve an integrated biorefinery of woody biomass. Among these value-added products, lignin-based derivatives with good surface activity can be applied to enhance the conversion of cellulose into fermentable sugars, which not only decrease the cost of bioethanol production, but also reduce the environmental pollution and green house effect resulting from the burning of fossil resources. Results Water-soluble alkaline lignin was synthesized by the reaction between polyethylene glycols (PEG600 and PEG1000) and epoxy lignin. FT-IR and NMR analyses indicated that PEGs were successively introduced into epoxy alkaline lignin using potassium persulfate as a catalyst. Emulsification and surface activity tests indicated that the surface tension of the prepared lignin derivative solution was 43.30 mN/m at the critical micelle concentration (1.03 %). A stable emulsions layer was formed with hexanes and the emulsion particle diameter in the emulsion phase for all products was observed at 10–50 μm. The results of enzymatic hydrolysis indicated that the products derived from PEG1000-grafted lignin resulted in the highest increasing rate of 18.6 % of glucose yield during the enzymatic hydrolysis of hardwood bleached pulp. The results of fermentation experiments suggested that the product had no toxicity for fermentation micro-organisms. Conclusion Water-soluble alkaline lignin derivatives were prepared through epoxidation and etherification, which are promising feedstocks for detergents, emulsifier, and additive to enhance enzymatic hydrolysis efficiency and ethanol fermentation. Electronic supplementary material The online version of this article (doi:10.1186/s13068-016-0499-9) contains supplementary material, which is available to authorized users.