Coating zirconium oxide-nanocomposite with humic acid for recovery of mercury and chromium in hazardous waste of chemical oxygen demand test

Hazardous waste of chemical oxygen demand (COD) test (HWCOD) is one of the most common laboratory wastewaters,containing large amounts of H_(2)SO_(4)and highly toxic Cr^(3+)and Hg^(2+).Current treatment methods suffered from incomplete removal of Cr^(3+)and high-cost.Herein,a humic acid-coated zirconium oxide-resin nanocomposite (HA-HZO-201) was fabricated for efficient recovery of Cr^(3+)and Hg^(2+)in HWCOD.The synthesized HA-HZO-201 shows excellent tolerance to wide p H range (1–5) and high salinity (3.5 mol/L Na Cl),as well as adsorption capacity for Cr^(3+)(37.5 mg/g) and Hg^(2+)(121.3 mg/g).After treating with HA-HZO-201 by using a fixed-bed adsorption procedure,the final Cr^(3+)and Hg^(2+)concentrations in HWCOD decreased to 0.28 and 0.02 mg/L,respectively.In addition,the HA-HZO-201 can be regenerated by desorption and recovery of Cr^(3+)and Hg^(2+)using HNO_(3)and thiourea as eluents,respectively.After 5 cycles of adsorption/desorption,the removal efficiencies still reach up to86.0%for Cr^(3+)and 89.7%for Hg^(2+),indicating an excellent regeneration of HA-HZO-201.We hope this work open new opportunities for treatment of HWCODwith high-efficiency and low-cost.

Identification of p100 target promoters by chromatin immunoprecipitation-guided ligation and selection (ChIP-GLAS)

The multifunctional protein p100 is a vital transcriptional regulator that increases gene transcription by forming a physical bridge between promoter-specific transcription factors and the basal transcription machinery.To identify potential signal transduction pathways in which human p100 acts as a coregulator and to find target promoter regions that may interact with p100,we performed a promoter microarray assay called chromatin immunoprecipitation-guided ligation and selection(ChIP-GLAS).From this assay,we determined that a set of promoter fragments,including several factors in the transforming growth factor beta(TGF-β)signaling pathway,exhibited interaction with p100.The ChIP-GLAS data were validated by RT-PCR assessing the mRNA expression of various factors in the TGF-b signaling pathway in cell lines.

Effects of poly-(p-phenylene terephthamide) powder coated with polydopamine on ethylene-propylene-diene-terpolymer grafted maleic anhydride

In this paper, we report a technique for the surface modification of poly-(p-phenylene terephthamide)(PPTA) powder coated with polydopamine(PDOPA). We used air oxidation to self-polymerize dopamine(DOPA) to ensure that the PPTA powder was coated. Our results indicate that the modified surface of PPTA powder enhances compatibility with the polymer matrix without damaging its structure. Additionally, it is possible to control the coating thickness of PDOPA by regulating the reaction time. The modified PPTA powder improved the comprehensive property of ethylene-propylene-diene-terpolymer grafted maleic anhydride(EPDM-g-MAH), and it proved that this method can enhance the strength and electric insulativity of EPDM-g-MAH.

One-step preparation of porous aminated-silica nanoparticles and their antibacterial drug delivery applications

Porous functionalized silica nanoparticles have attracted the interest of researchers as they are excellent carriers for antibacterial drug delivery applications.In this work,porous aminated-silica nanoparticles(SiO2-NH2 NPs) were prepared via one-step approach through the ammonia-catalyzed hydrolysis of tetraethylorthosilicate(TEOS) and(3-aminopropyl) triethoxysilane(APTES) in a mixed water-ethanol system.The obtained SiO2-NH2 NPs displayed a spherical morphology and relatively uniform size distribution,while the morphology and structure of SiO2-NH2 NPs were mainly determined by the order of the reagents added and the pH value of the solution.After characterization,the results showed that there were a large number of-NH2 groups on the surface of porous SiO2-NH2 NPs and that the porous SiO2-NH2 NPs had a large surface area of 476 m2 g-1 with an average pore width of 4.3 nm.Through an absorbing-releasing experiment and bacterial test,those SiO2-NH2 NPs were found to exhibit efficient absorption and release of drugs as well as a pH-de pendent release pattern of epirubicin-loaded SiO2-NH2 NPs.Meanwhile,SiO2-NH2@capsaicin NPs exhibited antibacterial properties.Those porous SiO2-NH2 NPs could be a candidate for drug delivery for antibacterial applications owing to their tailored porous structure and high surface area.

Simultaneous size characterization and mass quantification of the in vivo core-biocorona structure and dissolved species of silver nanoparticles

Size characterization of silver nanoparticles with biomolecule corona（AgNP@BCs） and mass quantification of various silver species in organisms are essential for understanding the in vivo transformation of Ag NPs. Herein, we report a versatile method that allows simultaneous determination of the size of AgNP@BCs and mass concentration of various silver species in rat liver. Both particulate and ionic silver were extracted in their original forms from the organs by alkaline digestion, and analyzed by size exclusion chromatography combined with inductively coupled plasma mass spectrometry（SEC-ICP-MS）. While the silver mass concentrations were quantified by ICP-MS with a detection limit of 0.1 μg/g, the effective diameter of AgNP@BCs was determined based on the retention time in SEC separation with size discrimination of 0.6-3.3 nm. More importantly, we found that the BC thickness of AgNP@BCs is core size independent, and a linear correlation was found between the effective diameter and core diameter of AgNP@BCs in extracted tissues, which was used to calibrate the core diameter with standard deviations in the range of 0.2-1.1 nm. The utility of this strategy was demonstrated through application to rat livers in vivo. Our method is powerful for investigating the transformation mechanism of Ag NPs in vivo.

Excipient-free porphyrin/SN-38 based nanotheranostics for drug delivery and cell imaging

Nanotheranostics with comprehensive diagnostic and therapeutic capabilities show exciting cancer treatment potentials.Here,we develop an excipient-free drug delivery system for cancer diagnosis as well as therapy,in which a near infra-red photosensitizer and a chemotherapeutic drug can be self-delivered without any carriers.The building block of the drug delivery system was synthesized by covalently conjugating four anticancer drugs(7-ethyl-10-hydroxy-camptothecin,SN-38)with a photosensitizer(porphyrin)via hydrolyzable ester linkage,which endows the drug delivery system with 100%active pharmaceutical ingredients,excellent imaging,and therapeutic functionalities.The conjugates can readily self-assemble into nanosheets(PS NSs)and remain stable for at least 20 days in aqueous solution.In PS NSs,fluorescence resonance energy transfer(FRET)dominates the fluorescence of SN-38 and enables to monitor the drug release fluorescentiy.The PS NSs also show excellent anticancer activity in vitro,due to the increased cell uptake with the synergistic effect of photodynamic therapy and chemotherapy.

Synthesis of highly-branched Au@AgPd core/shell nanoflowers for in situ SERS monitoring of catalytic reactions

Alloy and small size nanostructure s are favorable to catalytical performance,but not to surface-enhanced Raman spectroscopy(SERS) applications.Integrating SERS and catalytic activity into the nanocrystals with both alloy and small size structures is of great interest in fabrication of SERS platform to in situ monitor catalytical reaction.Herein,we report a facile method to synthesize Au@AgPd trimetallic nanoflowers(Au@AgPd NFs) with both SERS and catalytic activities,through simultaneous selective growth of Ag and Pd on Au core to form highly-branched alloy shell.These nanocrystals have the properties of small sizes,defects abundance,and highly-dispersed alloy shell which offer superior catalytic activity,while the merits of monodisperse,excellent stability,and highly-branched shell and core/alloy-shell structure promise the enhanced SERS activity.We further studied their growth mechanisms,and found that the ratio of Ag to Pd,sizes of Au core,and surfactant cetyltrimethylammonium bromide together determine this special structure.Using this as-synthesized nanocrystals,a monolayer bifunctional platform with both SERS and catalytical activity was fabricated through selfassembly at air/water interface,and applied to in situ SERS monitoring the reaction process of Pdcatalyzed hydrogenation of 4-nitrothiophenol to 4-aminothio p henol.

Flexible coatings with microphase separation structure attained by copolymers and ultra-fine nanoparticles for endurable antifouling

Incorporating antibacterial agent into biomimetic coating inspired by natural organisms with micronano structure surface has generated more interest for antifouling applications.In this work,poly(dimethylsiloxane)(PDMS)-based triblock copolymers and sub-20 nm nanoparticles Ag and heterogeneous Fe_(3)O_(4)-coated Ag(Fe_(3)O_(4)@Ag)were used to construct microphase separation topography with oriented copolymer blocks structure.The artificial surface was verified by atomic force microscopy and scanning electron microscopy images.Meanwhile,the surface exhibited relative stable hydrophobic property,which was demonstrated by the water contact angle and dynamic air-bubble contact angle measurements.Consequently,after immersed in BSA solution 24 h and 720 h,the actual BSA absorption amount of the surface with Fe_(3)O_(4)@Ag nanoparticles was as low as 10%and 27%that of the initial BSA amount,respectively.Moreover,the surface also showed remarkable antibacterial performance,which effectively suppressed the growth rate of Escherichia coli.The strategy of constructing the flexible micro p hase separation structure by introducing heterogeneous inorganic antibacterial nanoparticles into a block copolymer substrate opens up a new way to create an antifouling surface coating.

Solvent-free Synthesis of Flowable Carbon Clusters with Customizable Size and Tunable Optical Performance

We propose a rapid and solvent-flee route for synthesizing luminous carbon clusters by controlling carbonization of polyethylene glycol （PEG）. This approach does not involve solvents yet uses the precursor itself as suspend- ing medium, thus features mild and green chemistry, and also enables the formation of uniform-sized carbon clus- ters, of which the diameter can be easily tuned from 0.7 to 3.5 nm via control of reaction time. In term of the di- mension, the resultants are denoted as sub-nano carbon clusters （SNCs） and carbon dots （CDs）, respectively. Bene- fiting from surface anchored PEG segments, both of the two show favorable flowability at room temperature and excellent solubility in aqueous and organic solvents. Comparison of their optical performances and structures re- veals that they share the same chromophores. Particularly, the SNCs demonstrate robust photo- and pH-stable pho- toluminescence and can be directly applied to cell-imaging regarding to its prominent biocompatibility. Moreover, its quantum yield （5.5%）, which is approximately 3 times higher than that of CDs （1.5%）, can be dramatically en- hanced to 18.8% by facile chemical reduction. We anticipate that these PEG derivatives marked with easy synthesis, controllable optical performances and excellent physical properties will be highly appealing in future applications.