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oe1(光电查) - 科学论文

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出版时间
  • 2019
研究主题
  • Au nanoparticles in water
  • Fourier-Zhukovsky thermal model
应用领域
  • Nanomaterials and Technology
机构单位
  • National Institute for Laser, Plasma and Radiation Physics
1355 条数据
?? 中文（中国） ▾

  • dz2 Orbitals Mediated Bound Magnetic Polarons in Ferromagnetic Ce Doped BaTiO3 Nanoparticles and its Enriched Two Photon Absorption Cross Section

    摘要： Enriched ferromagnetism and two photon absorption (TPA) cross section of perovskite BaTiO3 nanoparticles are indispensible for magnetic and optical data storage applications. In this work, the hydrothermally synthesized Ce doped BaTiO3 nanoparticles exhibit the maximum room temperature ferromagnetism (4.26×10-3 emu/g) at 4 mol% due to the increase of oxygen vacancies as evidenced by X-ray photoelectron, electron spin resonance spectroscopies and density functional theory (DFT) calculations. Hence, the oxygen vacancy constituted bound magnetic polaron (BMP) model has been invoked to explain the enhancement of ferromagnetism. BMP theoretical model indicates the increase of BMP magnetization (M0, 3.0 to 4.8×10-3 emu/g) and true spontaneous moment per BMP (meff, 4 to 9.88×10-4 emu) on Ce doping. DFT calculations show that BMPs mediate via Ti d orbitals leading to the ferromagnetism. Besides, it is understood that the magnetic moment induced by Ce at Ba site is higher than Ce at Ti site in the presence of oxygen vacancies. Open aperture Z-scan technique displays the highest TPA coefficient β (7.08×10-10 m/W) and TPA cross section σTPA (455×104 GM) at 4 mol% of Ce as a result of robust TPA induced excited state absorption. A large σTPA is attributed to the longer excited state lifetime τ (7.63 ns) of charge carriers created by oxygen vacancies and Ce ions which encounter several electronic transitions in the excited sub-states.

    关键词： Ce doping,oxygen vacancies,bound magnetic polarons,two photon absorption,DFT calculations,Z-scan technique,BaTiO3 nanoparticles,ferromagnetism

    更新于2025-11-19 16:56:35

  • Melanin-like nanoparticles decorated with an autophagy-inducing peptide for efficient targeted photothermal therapy

    摘要： Photothermal therapy efficiently ablates tumors via hyperthermia but inevitably induces serious side effects including thermal damage to normal tissues, inflammations and enhanced risk of tumor metastasis. In this study, we fabricated a dual peptide decorated melanin-like nanoparticle for tumor-targeted and autophagy-promoted photothermal therapy in pursuit of improved cancer treatment. The multifunctional nanoparticle was composed of dual peptide RGD- and beclin 1-modified and PEGylated melanin-like polydopamine nanoparticles. Beclin 1-derived peptide modified on the nanoparticle up-regulated autophagy in cancer cells and further sensitized the photothermal ablation to tumors. RGD decorated on the particle surface enhanced the selectivity and cellular uptake of polydopamine nanoparticles by breast cancer cells. In vivo therapeutic experiments revealed that the tumor-targeted and autophagy promotion-associated photothermal therapy efficiently regressed tumors at a low temperature around 43 oC. The study provides a novel and efficient strategy to improve the efficiency of photothermal therapy via the up-regulation of autophagy in tumor cells.

    关键词： photothermal therapy,beclin 1,multifunctional nanoparticles,autophagy,melanin-like

    更新于2025-11-19 16:56:35

  • Study of the Effect of Optical Illumination on Resistive Switching in ZrO2(Y) Films with Au Nanoparticles by Tunneling Atomic Force Microscopy

    摘要： The effect of optical illumination on the resistive switching in ultrathin (~4 nm) ZrO2(Y) films with embedded single-layer Au nanoparticle arrays 2–3 nm in size is studied via tunneling atomic force microscopy. The ZrO2(Y) films with Au nanoparticles are grown by layerwise magnetron deposition onto glass substrates with a conductive indium-tin-oxide sublayer, followed by annealing at 450°C. An increase in hysteresis due to bipolar resistive switching in the ZrO2(Y) films is observed on the cyclic current–voltage curves of the microscope probe-to-sample contact. The effect is found to manifest itself in a dense Au nanoparticle array (~660 nm) when the contact area is photoexcited through a transparent substrate exposed to the radiation of a semiconductor laser at the plasmon-resonance wavelength. The effect is attributed to the photon-assisted field emission of electrons from Au nanoparticles to the conduction band of ZrO2(Y) in a strong electric field between the microscope probe and the indium-tin-oxide substrate under plasmon-resonance conditions.

    关键词： plasmon resonance,resistive switching,yttrium-stabilized zirconium dioxide,metal nanoparticles,atomic force microscopy

    更新于2025-11-19 16:56:35

  • MSOT/CT/MR imaging Guided and hypoxia Maneuvered Oxygen self-sufficiency radiotherapy based on One-pot MnO2-mSiO2 @ Au nanoparticle

    摘要： Radiotherapy (RT) is one of the most widely applied treatments for cancer therapy in the clinic. Herein, we constructed an innovative multifunctional nanotheranostic MnO2-mSiO2@Au-HA nanoparticles (MAHNPs) based on one-pot MnO2-mSiO2 nanohybrids (MNHs) and gold nanoparticles (AuNPs) for multispectral optoacoustic tomography (MSOT)/ computed tomography (CT) and magnetic resonance (MR) imaging guided hypoxia-maneuvered radiotherapy. The MNHs were prepared by a facile one-pot approach which avoided the leakage of MnO2 nanoparticles as well as increased the efficiency on preparation. The Mn2+ ions could trigger the breakdown of endogenous H2O2 to generate O2 to convert the hypoxic tumor micro-environment (TME), thus enhancing radiotherapy by self-sufficiency oxygen. In addition, hyaluronic acid (HA) was employed to modify the surface of MnO2-mSiO2@Au nanoparticles to improve biocompatibility and cellular uptake. The well-designed nanoparticles could perform remarkable photothermal therapy (PTT) and hypoxia-maneuvered radiotherapy (RT) simultaneously as well as MSOT/CT/MR imaging. In vivo studies showed that MAHNPs achieved almost entirely suppression of tumor growth without observable recurrence, which raised new possibilities for clinical nanotheranostics with multimodal diagnostic and therapeutic coalescent design.

    关键词： photothermal therapy (PTT),gold nanoparticles,nanotheranostics,MSOT/CT/MR imaging,hypoxia-maneuvered radiotherapy,MnO2-mSiO2 nanohybrids

    更新于2025-11-19 16:56:35

  • Atmospheric Pressure Plasma Synthesized Gold Nanoparticle/Carbon Nanotube Hybrids for Photo-thermal Conversion

    摘要： In this work, a room temperature atmospheric pressure direct-current plasma has been deployed for the one-step synthesis of gold nanoparticle/carboxyl group functionalized carbon nanotube (AuNP/CNT-COOH) nanohybrids in aqueous solution for the first time. Uniformly distributed AuNPs are formed on the surface of CNT-COOH, without the use of reducing agents or surfactants. The size of the AuNP can be tuned by changing the gold salt precursor concertation. UV-Vis, ζ-potential and X-ray photoelectron spectroscopy suggest that carboxyl surface functional groups on CNTs served as nucleation and growth sites for AuNPs and the multiple potential reaction pathways induced by the plasma-chemistry have been elucidated in detail. The nanohybrids exhibit significantly enhanced Raman scattering and photothermal conversion efficiency, properties that are essential for potential multi-modal cancer treatment applications.

    关键词： Surface Enhanced Raman Scattering,Gold Nanoparticles,Photothermal Conversion,Carbon Nanotubes,Plasma Synthesis

    更新于2025-11-19 16:56:35

  • Deposition of gold nanoparticles upon bare and indium tin oxide film coated glass based on annealing process

    摘要： We presented a simple and efficient strategy for deposition of gold nanoparticles (AuNPs) upon transparent bare and indium tin oxide (ITO) film coated glass substrate using gold colloids as Au sources. The method involved two steps: embedding in polyvinyl alcohol (PVA) film and annealing at high temperature. The AuNPs deposited on solid substrate because of migration and coalescence of gold at high temperature. The optical and structural properties of the AuNPs were characterised by UV-vis absorption spectra and scanning electron microscopy. The results indicate that the surface of AuNPs upon substrate was clean as annealing at 600 °C for 0.5 h. The size of AuNPs deposited on ITO glass increased with annealing time and volume of PVA-AuNPs. Meanwhile, the localised surface plasmon resonance peak of AuNPs deposited on substrate was also gradual red-shift. In addition, the size of AuNPs deposited on ITO substrate was larger than that on bare glass. This work provides a simple, low-cost and large-scale method for fabrication of substrate-based AuNPs, which is benefit for exploiting biosensors, photonic devices and optoelectronic devices.

    关键词： thermal annealing,solid substrate,Gold nanoparticles,indium tin oxide film coated glass

    更新于2025-11-19 16:56:35

  • The coherence between TiO2 nanoparticles and microfibrillated cellulose in thin film for enhanced dispersal and photodegradation of dye

    摘要： Microfibrillated cellulose (MFC) was used to enhance the dispersal and photocatalytic properties of TiO2 nanoparticles. With the small amount of MFC (0.1 wt.% or 0.3 wt.%), TEM images showed that particle agglomeration was greatly minimized due to the coherence between TiO2 nanoparticles and MFC. The surface area and pore volume of TiO2 nanoparticles was enhanced as proven in N2 adsorption-desorption analysis. Thermogravimetric and Fourier transform infrared spectra further confirmed the presence of MFC in TiO2/MFC coating solution. Using commercial adhesive, TiO2 and TiO2/MFC were spray coated on polyvinyl chloride sheet. The photocatalytic thin films were examined using scanning electron microscope with Energy dispersive X-ray analysis. The presence of MFC was not only helpful to enhance particle dispersal but also supportive to increase the hydrophilicity of the thin film. In comparison to TiO2 coating, the films were capable to adsorb 50% more methylene blue in 90 min. TiO2/MFC coatings removed 90% of methylene blue dye in 90 min under UV irradiation.

    关键词： Spray coating,Photocatalysis,Dye,TiO2 nanoparticles,Microfibrillated cellulose,Adsorption

    更新于2025-11-19 16:56:35

  • LSPR Biosensing Approach for the Detection of Microtubule Nucleation

    摘要： Microtubules are dynamic protein ?laments that are involved in a number of cellular processes. Here, we report the development of a novel localized surface plasmon resonance (LSPR) biosensing approach for investigating one aspect of microtubule dynamics that is not well understood, namely, nucleation. Using a modi?ed Mie theory with radially variable refractive index, we construct a theoretical model to describe the optical response of gold nanoparticles when microtubules form around them. The model predicts that the extinction maximum wavelength is sensitive to a change in the local refractive index induced by microtubule nucleation within a few tens of nanometers from the nanoparticle surface, but insensitive to a change in the refractive index outside this region caused by microtubule elongation. As a proof of concept to demonstrate that LSPR can be used for detecting microtubule nucleation experimentally, we induce spontaneous microtubule formation around gold nanoparticles by immobilizing tubulin subunits on the nanoparticles. We ?nd that, consistent with the theoretical model, there is a redshift in the extinction maximum wavelength upon the formation of short microtubules around the nanoparticles, but no signi?cant change in maximum wavelength when the microtubules are elongated. We also perform kinetic experiments and demonstrate that the maximum wavelength is sensitive to the microtubule nuclei assembly even when microtubules are too small to be detected from an optical density measurement.

    关键词： localized surface plasmon resonance,optical biosensors,gold nanoparticles,microtubule nucleation

    更新于2025-11-19 16:56:35

  • Opposite changing dual-emission luminescence of gold nanoparticles by sulfhydryl to develop a pesticide biosensing strategy

    摘要： As the merit of ratiometric assay is impregnable due to potentially interfering processes, a ratiometric method for pesticide detection was developed. By adjusting glutathione : HAuCl4 to an appropriate ratio, dual-emission luminescent ultra-small gold nanoparticles (AuNPs) with a high emission at 800 nm and a low emission at 600 nm were synthesized. Interestingly, the sulfhydryl-containing compounds were found to result in completely opposite changes to strengthen the 600 nm emission and weaken the 800 nm emission. Therefore, dual-emitted AuNPs were engaged to develop a ratiometric pesticide biosensing strategy. In the presence of acetylcholinesterase (AChE), acetylthiocholine can be hydrolyzed into thiocholine, whose newly generated sulfhydryl can interact with AuNPs, resulting in the opposite change of the dual emissions. While adding pesticide as an AChE inhibitor, the catalytic activity of AChE is inhibited and less thiocholine was produced. The biosensing system shows an obvious sensitivity to the pesticide with a limit of detection (LOD) of 0.2 nM for aldicarb and 0.07 nM for chlorpyrifos. Therefore, this simple assay is suitable for AChE activity and pesticide detection, even in vegetable samples.

    关键词： sulfhydryl,ratiometric assay,gold nanoparticles,AChE activity,biosensing,pesticide detection

    更新于2025-11-19 16:56:35

  • Synergistic Effects of Photo-Irradiation and Curcumin-Chitosan/Alginate Nanoparticles on Tumor Necrosis Factor-Alpha-Induced Psoriasis-Like Proliferation of Keratinocytes

    摘要： Psoriasis is a chronic inflammatory skin disease characterized by hyperproliferation of the epidermal cells and is clinically presented as thick, bright red to pink plaques with a silvery scale. Photodynamic therapy (PDT) using visible light has become of increasing interest in the treatment of inflammatory skin diseases. In this study, we demonstrate that a combination of curcumin-loaded chitosan/alginate nanoparticles (Cur-CS/Alg NPs) and blue light emitting diodes (LED) light irradiation effectively suppressed the hyperproliferation of tumor necrosis factor-alpha (TNF-α)-induced cultured human kerlatinocyte (HaCaT) cells. The Cur-CS/Alg NPs were fabricated by emulsification of curcumin in aqueous sodium alginate solution and ionotropic gelation with calcium chloride and chitosan using an optimized formulation derived from a Box-Behnken design. The fabricated Cur-CS/Alg NPs were characterized for their particle size, zeta potential, encapsulation efficiency, and loading capacity. The surrogate 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, to measure the relative number of viable cells, showed that the CS/Alg NPs were nontoxic to normal HaCaT cells, while 0.05 μg/mL and 0.1 μg/mL of free curcumin and Cur-CS/Alg NPs inhibited the hyperproliferation of HaCaT cells induced by TNF-α. However, the Cur-CS/Alg NPs demonstrated a stronger effect than the free curcumin, especially when combined with blue light irradiation (10 J/cm2) from an LED-based illumination device. Therefore, the Cur-CS/Alg NPs with blue LED light could be potentially developed into an effective PDT system for the treatment of psoriasis.

    关键词： LED light,chitosan/alginate nanoparticles,curcumin,photo-irradiation,psoriasis

    更新于2025-11-19 16:56:35