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The capability of single-walled carbon nanotubes (SWNTs) to specifically induce human telomeric i-motif formation has helped in designing an electrochemical DNA (E-DNA) sensor that can distinguish single- and multiwalled carbon nanotubes both in buffer and in cells extracts. The E-DNA sensor can selectively detect SWNTs with a direct detection limit of 0.2 ppm and is shown in cancer cell extracts.

With the continuous exposure of environmental pollutants in organisms, determination of abundance variation and spatial distribution of lipids might expand our understanding of toxicological mechanisms occurring in the kidney. Herein, an integrated method involving mass spectrometry (MS)-based lipidomics and matrix-assisted laser desorption/ionization-MS imaging (MALDI-MSI) was developed for the study of nephrotoxicity in mice exposed to 10 and 100 μg bisphenol S (BPS)/kg body weight/day. The BPS exposure remarkable perturbed abundances of 91 potential markers that mainly involved in five metabolic pathways. We elucidated the lipids spatial heterogeneity by using morphological analysis, probabilistic latent semantic analysis, and coregistered multimodal three-dimensional (3D)-MSI. In morphological analysis, both 10 and 100 μg BPS induced significant nephrotoxicity to mice, including glomerular necrosis in renal cortex, cloudy swelling in renal medulla, and interstitial collapsing in renal pelvis. Significant differential signaling lipids such as sphingomyelin (SM) (d22:0/20:4), ceramide (Cer) (d18:2/24:1), and sphingosine (d18:0) related to inflammation were found to be up-regulated and colocalized in the renal cortex, medulla, and pelvis, respectively. Also, seven significant differential lipids, which are considered to be involved in membrane homeostasis and cellular function, were found to be colocalized in the renal cortex. The observed significant variations of morphology, lipid accumulation, and metabolism in the renal cortex implicated that lipids in the renal cortex were more sensitive to BPS exposure than those in the renal medulla and pelvis. Moreover, we reconstructed a 3D-MSI model of kidney and identified two heterogeneous-related substructures in the renal cortex and pelvis upon 100 μg BPS exposure. It might be used in novel specificity evaluation and early diagnosis for environmental pollutant-induced kidney diseases. [ABSTRACT FROM AUTHOR]

The synthesis of soluble, conjugated poly(Zn-salphen)-alt-(p-phenyleneethynylene)s with a coilable structure and bearing acetylated sugar substituents is described, and their photophysical properties and conformational behavior have been investigated. Their CD spectra confirm that these systems are chiral, and signify ordered (helical) coiling of the polymer backbone arising from chirality transfer from the β-d-glucopyranosyl groups. The consequences of varying side-chain substituents as well as the extent of inter- and intrachain [p-stacking and Zn···O(salphen)] interactions have been studied, and comparisons with the corresponding linear-rod and Pt-based congeners have been made. Analysis of the effects of different solvents on these systems by UV-vis absorption, emission, and CD spectroscopy indicates that low-polarity solvents give a tighter, more compressed helical structure with increased CD intensities, while coordinating solvents can perturb the folded conformation to afford a more extended coiled structure with decreased Cotton effects. These observations, together with variable-temperature CD experiments, point to the flexibility and dynamic nature of the helical conformation. [ABSTRACT FROM AUTHOR]

Currently, designing high-performance structured catalysts is full of significance for economic and sustainable production of chemicals due to the catalysts easy separation and recovery and excellent heat/mass transfer characteristics. Herein, we reported the synthesis of a ternary Co-Ni-Al mixed-metal oxide (CoNiAl-MMO) film with surface intercrossed and vertically aligned nanoplatelets via an in situ growth route. CoNiAl-MMO film exhibited greatly enhanced catalytic performance in the oxidation of benzyl alcohol, compared with binary MAl-MMO films (M = Co or Ni) and pristine CoNiAl-MMO powder. The improved catalytic efficiency was attributable to a synergistic effect between highly dispersed active Co and Ni species, as well as the presence of more surface oxygen vacancies. Moreover, the film possessed extremely high structural stability stemming from the strong interaction between the CoNiAl-MMO layer and the substrate. Such type of structured non-noble-metal film catalyst may have potential industrial applications in a broad range of heterogeneous catalysis systems in the future. [ABSTRACT FROM AUTHOR]

A droop-free nitride light-emitting diode (LED) with the capacity to operate beyond the "green gap" has been a subject of intense scientific and engineering interest. While several properties of nanowires on silicon make them promising for use in LED development, the high aspect ratio of individual nanowires and their laterally discontinuous features limit phonon transport and device performance. Here, we report on the monolithic integration of metal heat-sink and droop-free InGaN/GaN quantum-disks-in-nanowire LEDs emitting at ∼710 nm. The reliable operation of our uncooled nanowire-LEDs (NW-LEDs) epitaxially grown on molybdenum was evident in the constant-current soft burn-in performed on a 380 μm × 380 μm LED. The square LED sustained 600 mA electrical stress over an 8 h period, providing stable light output at maturity without catastrophic failure. The absence of carrier and phonon transport barriers in NW-LEDs was further inferred from current-dependent Raman measurements (up to 700 mA), which revealed the low self-heating. The radiative recombination rates of NW-LEDs between room temperature and 40 °C was not limited by Shockley-Read-Hall recombination, Auger recombination, or carrier leakage mechanisms, thus realizing droop-free operation. The discovery of reliable, droop-free devices constitutes significant progress toward the development of nanowires for practical applications. Our monolithic approach realized a high-performance device that will revolutionize the way high power, low-junction-temperature LED lamps are manufactured for solid-state lighting and for applications in high-temperature harsh environment. [ABSTRACT FROM AUTHOR]

High-quality nitride materials grown on scalable and low-cost metallic substrates are considerably attractive for high-power light-emitters. We demonstrate here, for the first time, the high-power red (705 nm) InGaN/GaN quantum-disks (Qdisks)-in-nanowire light-emitting diodes (LEDs) self-assembled directly on metal-substrates. The LEDs exhibited a low turn-on voltage of ~2 V without efficiency droop up to injection current of 500 mA (1.6 kA/cm²) at ~5 V. This is achieved through the direct growth and optimization of high-quality nanowires on titanium (Ti) coated bulk polycrystalline-molybdenum (Mo) substrates. We performed extensive studies on the growth mechanisms, obtained high-crystal-quality nanowires, and confirmed the epitaxial relationship between the cubic titanium nitride (TiN) transition layer and the hexagonal nanowires. The growth of nanowires on all-metal stack of TiN/Ti/Mo enables simultaneous implementation of n-metal contact, reflector, and heat sink, which greatly simplifies the fabrication process of high-power light-emitters. Our work ushers in a practical platform for high-power nanowires light-emitters, providing versatile solutions for multiple cross-disciplinary applications that are greatly enhanced by leveraging on the chemical stability of nitride materials, large specific surface of nanowires, chemical lift-off ready layer structures, and reusable Mo substrates. [ABSTRACT FROM AUTHOR]

A capillary monolithic bioreactor of snake venom phosphodiesterase (SVP) was constructed to generate different single-nucleotide mass ladders of oligodeoxynucleotides for mass spectrometry (MS)-based sequencing by immobilization. The immobilization of SVP in the porous silica monolith significantly enhances its stability for prolonged and repeated applications. The constructed capillary bioreactor has the advantages of handling (sub)microliter DNA samples and having good permeability. Benefiting from its good permeability, DNA solutions can be directly injected into the sequential digestion bioreactor simply by hand pushing or a low-pressure microinjection pump. Moreover, the immobilization of SVP facilitates the elimination or repression of the metal adducts of oligodeoxynucleotides, improving the analytical performance of MS sequencing. By the application of capillary bioreactor of immobilized SVP, the sequence-specific modification of single-stranded oligodeoxynucleotide induced by a ubiquitous pollutant acrolein (Acr) was identified, demonstrating its promising applications in identification of sequence-specific damage, which may further our understanding of DNA damage caused mutagenesis. [ABSTRACT FROM AUTHOR]

Development of biomaterials with long-term biocompatibility,durability,and stability remains a critical challenge for biomedical devices.Here, we synthesize, characterize, and graft poly(N-(2-hydroxyethyl)acrylamide) (polyHEAA) onto both gold surfaces andgold nanoparticles (AuNPs) via surface-initiated atom transfer radicalpolymerization (SI-ATRP) to form a stable antifouling coating to resistnonspecific protein adsorption and bacterial attachment. Surface plasmonresonance (SPR) results demonstrate that all of polyHEAA brushes coatedon the gold substrate at a wide range of film thickness of ∼10–40nm can achieve almost zero protein adsorption from undiluted bloodplasma and serum for 1 h, while static bacteria assay results showthat polyHEAA brushes prohibit long-term bacterial colonization by Staphylococcus epidermidisand Escherichia coliRP437up to 3 days. Moreover, the polyHEAA-coated AuNPs withdifferent diameters remain their hydrodynamic sizes unchanged in humanblood plasma and serum for up to 7 days. All these data indicate thatpolyHEAA can serve as promising biomaterials with long-term biocompatibilityand durability suitable for applications in complex biological media. [ABSTRACT FROM AUTHOR]

We demonstrated the synthesis of five kinds of microporous organic polymers based on aldol self-condensation of di- and multiacetyl-containing building blocks catalyzed by thionyl chloride. The α,β-unsaturated ketone (dimerization) and 1,3,5-trisubstituted benzene (cyclotrimerization) can be observed in the resulting polymers by Fourier transform infrared and solid-state 13C CP/MAS NMR spectroscopy. The regular spheres and nanometer-scaled cavities were also seen from scanning electron microscopy and high-resolution transmission electron microscopy images. The highest Brunauer–Emmet–Teller specific surface area up to 832 m2g–1was obtained for the resulting polymers with a pore volume of 0.48 cm3g–1. The polymers show great hydrogen storage capacities (up to 1.56 wt %) at 77 K and 1 bar. These excellent characteristics would make them become promising candidates for heterogeneous catalysis, separation, and gas storage. [ABSTRACT FROM AUTHOR]

The development of nonfouling biomaterials to prevent nonspecific protein adsorption and cell/bacterial adhesion is critical for many biomedical applications, such as antithrombogenic implants and biosensors. In this work, we polymerize two types of hydroxy-functional methacrylates monomers of 2-hydroxyethyl methacrylate (HEMA) and hydroxypropyl methacrylate (HPMA) into polymer brushes on the gold substrate via surface-initiated atom transfer radical polymerization (SI-ATRP). We systematically examine the effect of the film thickness of polyHEMA and polyHPMA brushes on their antifouling performance in a wide range of biological media including single-protein solution, both diluted and undiluted human blood serum and plasma, and bacteria culture. Surface plasmon resonance (SPR) results show a strong correlation between antifouling property and film thickness. Too thin or too thick polymer brushes lead to large protein adsorption. Surfaces with the appropriate film thickness of ∼25−45 nm for polyHPMA and ∼20−45 nm for polyHEMA can achieve almost zero protein adsorption (<0.3 ng/cm2) from single-protein solution and diluted human blood plasma and serum. For undiluted human blood serum and plasma, polyHEMA brushes at a film thickness of ∼20−30 nm adsorb only ∼3.0 and ∼3.5 ng/cm2proteins, respectively, while polyHPMA brushes at a film thickness of ∼30 nm adsorb more proteins of ∼13.5 and ∼50.0 ng/cm2, respectively. Moreover, both polyHEMA and polyHPMA brushes with optimal film thickness exhibit very low bacteria adhesion. The excellent antifouling ability and long-term stability of polyHEMA and polyHPMA brushes make them, especially for polyHEMA, effective and stable antifouling materials for usage in blood-contacting devices. [ABSTRACT FROM AUTHOR]

Human blood plasma and serum pose significant challenges to implanted devices because of highly unfavorable nonspecific protein adsorption on the surface. In this work, we introduce an improved two-step method to immobilize initiator thiols on a gold substrate for the surface-initiated atom-transfer radical polymerization (SI-ATRP) of hydroxypropyl methacrylate (HPMA). We investigate protein adsorption from a single-protein solution, diluted (10%) and undiluted (100%) human blood plasma, and serum on the poly(HPMA) brushes with different film thicknesses using surface plasmon resonance (SPR) sensors. SPR results show a correlation between antifouling properties and film thickness; that is, the poly(HPMA) brushes exhibit high protein resistance at medium film thicknesses of ∼25−40 nm (e.g. <0.3 ng/cm2for single-protein adsorption and 10% human blood plasma and serum, ∼24.5 ng/cm2for 100% human serum, and ∼52.8 ng/cm2for 100% human plasma at a thickness of ∼29 nm). With an optimal film thickness and surface roughness, the poly(HPMA) brush also demonstrates its high resistance to fibroblast adhesion. This work provides an alternative surface polymerization approach to preparing effective antifouling poly(HPMA) materials for potential applications in blood-contacting medical devices. [ABSTRACT FROM AUTHOR]

A novel luminescent Eu3+complex functionalized single-walled carbon nanotube (SWNT) was constructed by covalent linkage through a diaminotriethylene glycol linker. TGA, FT-IR, and SEM demonstrated successful attachment of the Eu3+complex onto the SWNT surface. Spectroscopic methods showed that the SWNT-Eu3犉ꦕ is highly luminescent and DNA can further enhance the red luminescence, and the enhancement depends on DNA sequence and form. The order of the enhancement follows: AT alternative dsDNA > nonalternative AT dsDNA > GC dsDNA > ssDNA dA > ssDNA dT > ssDNA (GT)20. [ABSTRACT FROM AUTHOR]