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Affinity analysis is a key biotechnique used in the fields of biology and biomedicine. Herein, we advanced the concept of moving affinity boundary (MAB) using metal ion Ni(II) and histidine (His) as the model inorganic ion and ligand, respectively, developed the simple method of MAB affinity capillary electrophoresis (MAB-ACE), and carried out the relative experiments. The experiments manifested that (a) an MAB could be created with the model metal ion and ligand; (b) the MAB-ACE could specifically capture His rather than other amino acids, or numerous metabolites in human urine; and (c) the capture had the merits of simultaneous focusing and separation to the target metabolite of His. It was further revealed that the specificity of MAB-ACE was originated from the selective affinity interaction and the effective control of affinity conditions. The analyses of His in raw urine by the MAB-ACE are in agreement with those via the standard amino acid analyzer, indicating the reliability of the developed method. Additionally, the MAB-ACE with UV detector had good sensitivity (LOD = 43 ng mL(-1), S/N = 3), 1.0-150 microM linearity and <5% intra-/inter-day variations. The novel method has an evident potential application for capture of a target metabolite in complex biological sample.

Gallium−indium eutectic (eGaIn) is a liquid metal being explored in a number of applications because of its high thermal/electrical conductivity and favorable deformability. A key function regulating the mechanical properties of eGaIn is the ability to rapidly form a passivating oxide layer, which is known to occur upon exposure to air under ambient conditions. Nevertheless, little is known about the molecular level surface reactivity of eGaIn toward oxygen and water vapor under in situ conditions. Herein we present ambient pressure X-ray photoelectron spectroscopy results examining the liquid− gas interface of eGaIn in the presence of oxygen and water vapor. By examining each gas independently, results reveal that both oxygen and water vapor react with Ga in eGaIn to form the same oxidized products: Ga 3+ oxide (Ga 2 O 3 ) as an outer layer and Ga 1+ oxide (Ga 2 O) as an interlayer. Despite similar product formation, stark differences are observed in pressure-dependence and adsorbate-induced binding energy shifts. The results herein suggest both oxygen and water vapor uniquely contribute to the oxidative passivation of eGaIn under ambient conditions.

Recent advances in manipulating plasmonic properties of metal/semiconductor heterostructures have opened up new avenues for basic research and applications. Herein, we present a versatile strategy for the assembly of arrays...

Vertically aligned ZnO nanowire-based tree-like structures with CuO branches were synthesized on the basis of a multistep seed-mediated hydrothermal approach. The nanotrees form a p-n junction at the branch/stem interface that facilitates charge separation upon illumination. Photoelectrochemical measurements in different solvents show that ZnO/CuO hierarchical nanostructures have enhanced photocatalytic activity compared to that of the nonhierarchical structure of ZnO/CuO, pure ZnO, and pure CuO nanoparticles. The combination of ZnO and CuO in tree-like nanostructures provides opportunities for the design of photoelectrochemical sensors, photocatalytic synthesis, and solar energy conversion.

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We reported high performance anatase-TiO2 thin film transistors with a two-step oxidized TiO2 channel (O2 annealing and N2O plasma treatment) and O2 plasma enhanced atomic layer-deposited ZrO2 gate dielectric. The transistors using 60 nm TiO2 as the active channel exhibited a steep subthreshold swing of 112 mV dec−1 and a high on/off current ratio of 1.4 × 108. The superior performances, achieved by the two-step oxidizing process and the utilization of ZrO2 as the high-k gate dielectric, show their great potential to be applied in future electronic and optical systems, such as active-matrix displays and ultraviolet sensors.

In the present study, we focused on the intermolecular H-bonding interactions of poly­[(R)-3-hydroxybutyrate] (PHB) with an inorganic material, pseudoboehmite (PB), and their effect on PHB crystallization. Noncrystallizable atactic PHB and crystallizable isotactic PHB (a-PHB and i-PHB) ultrathin films were spin-coated on a PB substrate, as well as an aluminum oxide (AO) and a gold substrate for comparison. Infrared reflection–absorption spectroscopy (IRRAS) data show an absorption peak in the carbonyl region located at 1724 cm–1 for a 2.8 nm a-PHB film deposited on PB. A peak at this frequency, often observed for thick bulk crystalline i-PHB films, was not observed for a 1.4 nm a-PHB film deposited on a gold or AO substrate, indicating that the 1724 cm–1 peak observed for a-PHB on PB is not due to a geometric confinement effect or crystallization but due to the existence of intermolecular H-bonding (H-bondinter) between −CO of a-PHB and −OH from PB. Supercooled, amorphous i-PHB was also found to exhibit the same H-bondinter with PB. It was found that a PB surface significantly modified the crystal orientation and morphologies of the films. Grazing incident wide-angle X-ray diffraction (GIWAXD) data show that the crystallites in i-PHB on PB are randomly oriented, whereas those on AO are predominantly edge-on oriented. Polarized optical microscopy (POM) images show spherulites for i-PHB on AO, whereas no spherulites were observed for i-PHB on PB. This study demonstrates a novel method of using PB to modulate the crystallization behavior of PHB thin films.