Surface Single-Atom Tailoring of a Gold Nanoparticle

Surface single-atom tailoring of a gold nanoparticle, that is, adding, removing, or replacing one surface atom on a structure-resolved nanoparticle in a controlled manner, is very exciting yet challenging and has not been hitherto achieved. Herein we report the first realization of the introduction of a single sulfur atom onto the surface of the structure-unraveled Au₆₀S₆(SCH₂Ph)₃₆ nanoparticle. Single-crystal X-ray crystallography reveals that the as-obtained nanoparticle consists of one Au₁₇ kernel protected by one Au₂₀S₃(SCH₂Ph)₁₈ and one unprecedented Au₂₃S₄(SCH₂Ph)₁₈ motif with the introduced sulfur atom included as a tetrahedral-coordinated μ₄-S. The introduced sulfur leads to the changes of both internal structure and crystallographic arrangement. Unlike the case of 6HLH arrangement in Au₆₀S₆(SCH₂Ph)₃₆ crystals, the “ABAB” arrangement in Au₆₀S₇(SCH₂Ph)₃₆ crystals enhances the solid photoluminescence of amorphous Au₆₀S₇(SCH₂Ph)₃₆ and brings a slight redshift of the maximum emission. The extensive near-infrared emission provides Au₆₀S₇(SCH₂Ph)₃₆ potential applications in some fields such as anticounterfeiting, imaging, etc

Onion-Structured Spherical MoS₂ Nanoparticles Induced by Laser Ablation in Water and Liquid Droplets’ Radial Solidification/Oriented Growth Mechanism

Spherical MoS₂ nanoparticles are fabricated by laser ablation of MoS₂ target in water. The obtained nanoparticles are mostly nearly perfectly spherical in shape with smooth surface, and tens to hundreds of nanometers in diameters. Such spherical MoS₂ nanoparticles are built by concentrically curved {002} planes and show onion-like structure. Further examination has revealed that there exist shrinkage cavities (or voids) in the central part of the MoS₂ nanoparticles or small pores dispersed in the particles and a few tadpole-like long-tailed nanoparticles in the products, indicating the marks of melting and molten liquid droplets’ solidification during laser ablation. A model is thus presented based on laser-induced MoS₂ liquid droplets’ generation and inward {002}-oriented growth via radial solidification, which reveals the growth mechanism of the spherical MoS₂ nanoparticles with onion-like structure. Interestingly, such onion-like structured spherical MoS₂ nanoparticles have exhibited much higher surface-enhanced Raman scattering (SERS) effect than the MoS₂ nanoplates prepared by conventional methods. This work not only presents the route to the spherical MoS₂ nanoparticles with onion-like structure but also reveals the formation process for the MoS₂ nanoparticles in laser ablation in water

Ultrathin Oxide Layer-Wrapped Noble Metal Nanoparticles via Colloidal Electrostatic Self-Assembly for Efficient and Reusable Surface Enhanced Raman Scattering Substrates

Controllable and flexible fabrication of ultrathin and uniform oxide layer-wrapped noble metal nanoparticles (NPs) has been expected. Here a new strategy is presented for them based on colloidal electrostatic attraction and self-assembly on the metal NPs via one-step laser ablation of noble metal targets in the hydrolysis-induced hydroxide sol solutions at room temperature. The Au NPs, with several tens of nanometers in size, are taken as core part and TiO₂ as shell-layer to demonstrate the validity of the presented strategy. It has been shown that the TiO₂ shell-wrapped Au NPs are obtained after laser ablation of Au target in the hydrolysis-induced Ti­(OH)₄ sol solution. The Au NPs are about 35 nm in mean size, and the TiO₂ shell layers are amorphous in structure and about 2.5 nm in thickness. The shell thickness is nearly independent of the Au NPs’ size. Further experiments have shown that the thickness and crystallinity of the shell-layer can be tuned and controlled via changing the temperature or pH value of the Ti­(OH)₄ sol solution or prolonging the laser ablation duration. The formation of the TiO₂ shell-wrapped Au NPs is attributed to attachment and self-assembly of Ti­(OH)₄ colloids on the laser-induced Au NPs due to the electrostatic attraction between them. Importantly, the presented strategy is universal and suitable for fabrication of many other ultrathin oxide-wrapped noble metal NPs. A series of oxide shell-wrapped noble metal NPs have been successfully fabricated, such as Au@oxides (Fe₂O₃, Al₂O₃, CuO, and ZnO) as well as Pt@TiO₂ and Pd@TiO₂, etc. Further, compared with the pure gold NPs-built film, the TiO₂-wrapped Au NPs-built film has exhibited much stronger surface enhanced Raman scattering (SERS) performance to the anions NO₃^–, which weakly interact with noble metals, and the good reusability for the SERS-based detection of 4-nitrophenol, which could be photodegraded by xenon lamp irradiation. This work provides a flexible and universal route to the ultrathin and uniform oxide layer-wrapped noble metal NPs

Leaf-like Tungsten Oxide Nanoplatelets Induced by Laser Ablation in Liquid and Subsequent Aging

A facile and chemically clean method, pulsed laser ablation in liquid medium (LAL), was utilized to produce precursor solutions, and leaf-like tungsten oxide (WO₃) nanoplatelets were synthesized after sequential aging treatment of precursors. In this work, the effects of aging temperature, aging time, and pH value of precursor solutions have been investigated. The well-defined leaf-like WO₃ nanoplatelets can only be achieved by aging the pristine precursor solutions at room temperature (25 °C) for 48 h. In particular, when the pH value of precursor solutions was decreased lower than 1.0, the obtained products were hierarchical quasi-spheres composed of several nanoplates. The preparation method reported here shows a novel synthetic approach to control and adjust the morphology and crystallite size of the prepared WO₃ nanomaterials, which has potential applications in gas sensing, electrochromic devices, and photocatalysis

Large Area α‑Cu₂S Particle-Stacked Nanorod Arrays by Laser Ablation in Liquid and Their Strong Structurally Enhanced and Stable Visible Photoelectric Performances

A flexible route is developed for fabrication of large area α-Cu₂S nanorod arrays (NRAs) on the basis of one-step laser ablation of a copper foil in CS₂ liquid. It has been demonstrated that the obtained products are the high-temperature phase α-Cu₂S and consist of the nanorods vertically standing on the Cu foil, exhibiting the array. The nanorods were about 1 μm in length and around 100 nm in thickness and built by stacking the nearly spherical and ⟨110⟩-oriented nanoparticles (NPs) up. Such array can be peeled off from the foil and remain freestanding. Further, it has been found that the ablation duration, the laser power, and the foil surface state are crucial to the formation of the Cu₂S NRA. The formation of such oriented NP-stacked Cu₂S NRAs is attributed to the laser-induced generation of α-Cu₂S NPs and the NPs’ deposition/oriented connection growth on the surface-vulcanized copper foil. Importantly, the visible photocurrent response of the α-Cu₂S NRAs is 8 times higher than that of the Cu₂S NPs’ film with the equivalent thickness and also larger than that of previously reported Cu₂S, showing significantly enhanced photoelectric performances. As an application, such NRAs have exhibited markedly enhanced visible photocatalytic activity and highly stable recycling performances, compared with the α-Cu₂S NPs. Further studies have revealed that the enhanced performances are attributed to the structurally enhanced light trapping effect of the NRAs as well as short and smooth carrier diffusion path in the oriented NP-stacked nanorods. This work provides a new and simple method for fabrication of the large area Cu₂S NRAs with high and stable photoelectric performances

Fabrication of Gold Nanoparticles by Laser Ablation in Liquid and Their Application for Simultaneous Electrochemical Detection of Cd²⁺, Pb²⁺, Cu²⁺, Hg²⁺

In this paper, we demonstrated the fabrication of high active and high sensitive Au nanoparticles by laser ablation in liquid (LAL) method, and their application in electrochemical detection of heavy metal ions. First, LAL method are used to fabricate Au nanoparticles in water in a clean way. Second, the Au nanoparticles were assembled onto the surface of the glassy carbon (GC) electrode by an electrophoretic deposition method to form an AuNPs/GC electrode for electrochemical characterization and detection. Through differential pulse anodic stripping voltammetry method, it shows that the AuNPs/GC electrode could be used for the simultaneous and selective electrochemical detection of Cd²⁺, Pb²⁺, Cu²⁺, and Hg²⁺. By studying the influence of test conditions to optimize the electrochemical detection, we can detect Cd²⁺, Pb²⁺, Cu²⁺, and Hg²⁺ simultaneously with a low concentration of 3 × 10^–7 M in the experiments

General data.

<p>General data.</p

Effects of CYP3A4*1G and CYP3A5*3 polymorphisms on pharmacokinetics of tylerdipine hydrochloride in healthy Chinese subjects

<p></p><p>The aim of this analysis was to explore the influence of CYP3A4*1G and CYP3A5*3 polymorphisms on the pharmacokinetics of tylerdipine in healthy Chinese subjects.</p><p>A total of 64 and 63 healthy Chinese subjects were included and identified as the genotypes of CYP3A4*1G and CYP3A5*3, respectively. Plasma samples were collected for up to 120 h post-dose to characterize the pharmacokinetic profile following single oral dose of the drug (5, 15, 20, 25 and 30 mg). Plasma levels were measured by a high-performance liquid chromatography-mass spectrometry (LC-MS/MS). The pharmacokinetic parameters were calculated using non-compartmental method. The maximum concentration (<i>C</i>_max) and the area under the curve (AUC_0–24 h) were all corrected by the dose given.</p><p>In the wild-type group, the mean dose-corrected AUC_0–24 h was 1.35-fold larger than in CYP3A4*1G carriers (<i>p</i> = .018). Among the three CYP3A5 genotypes, there showed significantly difference (<i>p</i> = .008) in the <i>t</i>_1/2, but no significant difference was observed for the AUC_0–24 h and <i>C</i>_max. In subjects with the CYP3A5*3/*3 genotype, the mean <i>t</i>_1/2 was 1.35-fold higher than in CYP3A5*1/*1 group (<i>p</i> = .007). And the <i>t</i>_1/2 in CYP3A5*3 carriers also was 1.32-fold higher than in the wild-type group (<i>p</i> = .004).</p><p>CYP3A4*1G and CYP3A5*3 polymorphisms may influence tylerdipine pharmacokinetic in healthy Chinese subjects.</p><p></p> <p>The aim of this analysis was to explore the influence of CYP3A4*1G and CYP3A5*3 polymorphisms on the pharmacokinetics of tylerdipine in healthy Chinese subjects.</p> <p>A total of 64 and 63 healthy Chinese subjects were included and identified as the genotypes of CYP3A4*1G and CYP3A5*3, respectively. Plasma samples were collected for up to 120 h post-dose to characterize the pharmacokinetic profile following single oral dose of the drug (5, 15, 20, 25 and 30 mg). Plasma levels were measured by a high-performance liquid chromatography-mass spectrometry (LC-MS/MS). The pharmacokinetic parameters were calculated using non-compartmental method. The maximum concentration (<i>C</i>_max) and the area under the curve (AUC_0–24 h) were all corrected by the dose given.</p> <p>In the wild-type group, the mean dose-corrected AUC_0–24 h was 1.35-fold larger than in CYP3A4*1G carriers (<i>p</i> = .018). Among the three CYP3A5 genotypes, there showed significantly difference (<i>p</i> = .008) in the <i>t</i>_1/2, but no significant difference was observed for the AUC_0–24 h and <i>C</i>_max. In subjects with the CYP3A5*3/*3 genotype, the mean <i>t</i>_1/2 was 1.35-fold higher than in CYP3A5*1/*1 group (<i>p</i> = .007). And the <i>t</i>_1/2 in CYP3A5*3 carriers also was 1.32-fold higher than in the wild-type group (<i>p</i> = .004).</p> <p>CYP3A4*1G and CYP3A5*3 polymorphisms may influence tylerdipine pharmacokinetic in healthy Chinese subjects.</p

Type of previous pregnancy, pre-treatment β-HCG levels, maximum tumor diameter, and the total number of treatment courses to achieve normal β-HCG levels (x¯ ± s).

<p>Type of previous pregnancy, pre-treatment β-HCG levels, maximum tumor diameter, and the total number of treatment courses to achieve normal β-HCG levels (<math><mrow><mi>x</mi><mo>¯</mo></mrow></math> ± s).</p