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oe1(光电查) - 科学论文

265 条数据
?? 中文(中国)
  • Indian Gooseberry-Derived Tunable Fluorescent Carbon Dots as a Promise for In Vitro/In Vivo Multicolor Bioimaging and Fluorescent Ink

    摘要: We report the synthesis of eco-friendly fluorescent nitrogen-doped carbon dots (NCDs) using the renewable resource of Phyllanthus emblica juice as a precursor by the hydrothermal process at 200 °C for 12 h. The synthesized NCDs emitted bright fluorescence without any pretreatment of the sample under the excitation of UV light and exhibited excitation-dependent fluorescence emission. The NCDs have nitrogen-containing and oxygen-containing functional groups such as amino, hydroxyl, and carboxyl on the surface of the carbon structure. Furthermore, the NCDs exhibited excellent water dispersibility with prolonging stability and good biocompatibility. On the basis of the good optical properties, the NCDs have potentially been used as a promising staining agent on HCT-116 human colon cancer cells and Caenorhabditis elegans (nematodes) for multicolor cellular imaging. In the cell cytoplasm, the NCDs showed rapid uptake and high cytocompatibility on cellular morphology with bright fluorescence emission. Furthermore, the NCDs were used as fluorescent ink for writing and drawing with anticoagulation. In addition, the NCDs were significantly utilized as a fluorescent ink for thumb impression, which glows instantly under the illumination of UV light and does not require a secondary treatment. Hence, the synthesized NCDs can be used as ideal multicolor fluorescent probes for bioimaging applications and as fluorescent ink instead of traditional fluorescent ink.

    关键词: nitrogen-doped,hydrothermal synthesis,carbon dots,fluorescent ink,bioimaging

    更新于2025-09-04 15:30:14

  • Preparation of reduced Graphene Oxide (rGO) assisted by microwave irradiation and hydrothermal for reduction methods

    摘要: Graphite is a natural carbon source that can be used for graphene synthesis because of its abundant availability and relatively low cost. In this research, Graphene Oxide (GO) and reduced Graphene Oxide (rGO) have been prepared through modified Hummers method that uses microwave irradiation and hydrothermal process as reduction methods. This research can be divided into two main steps, i.e. preparation of GO and preparation of rGO. The preparation of GO was done using modified Hummers method that refers to graphite powder oxidation for five days. Then, preparation of rGO was done using two methods, i.e. microwave irradiation for 8 minutes at 1,000 watts and hydrothermal process for 10 hours at 200°C. The characterization of the samples was observed by Fourier-Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Ultraviolet-Visible Spectroscopy (UV-Vis). XRD pattern of GO sample shows a peak at 2θ = 10.63°, rGO sample from hydrothermal process at 2θ = 25.94°, and rGO sample from microwave irradiation method at 2θ = 25.94° with low intensity and at 2θ = 10.63° that indicates the presence of GO. IR spectroscopy data shows an absorption peak of aromatic C=C at 1,573 cm-1 that indicates rGO formation. SEM images of GO illustrates a structure of stacked flakes. While the morphology of rGO has a structure of stacked flakes that is more transparent than GO. According to UV-Vis spectroscopy, GO and rGO of samples show absorption peak at λmax = 225 nm and λmax = 274 nm, respectively, which indicates π→π* transition of aromatic C=C bond. Based on the results of this study, the preparation of rGO using modified Hummers that combined with hydrothermal reduction method is more effective than microwave irradiation reduction method.

    关键词: Graphene Oxide,hydrothermal process,Hummers method,reduced Graphene Oxide,microwave irradiation

    更新于2025-09-04 15:30:14

  • [IEEE 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Saint Petersburg, Russia (2018.10.22-2018.10.23)] 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Study of Gas-Sensitive Properties of Zinc Oxide Nanorod Array at Room Temperature

    摘要: In this paper, we present a technique for the synthesis of zinc oxide nanorods and the study of their sensitivity to organic solvent vapors. Zinc oxide nanorods were synthesized by hydrothermal method. Investigation of gas-sensitive properties was carried out by the method of impedance spectroscopy. Studies of gas-sensitive properties of zinc oxide showed a significant response of the system to the vapor of reducing gases at room temperature. It is shown that the thickness of the seed layer and, correspondingly, the density of the structure on the basis of ZnO nanorods, strongly affect the sensitivity of the sensor.

    关键词: impedance spectroscopy,nanorods,hydrothermal synthesis,zinc oxide,gas sensors

    更新于2025-09-04 15:30:14

  • Water-dispersed fluorescent silicon nanodots as probes for fluorometric determination of picric acid via energy transfer

    摘要: Water-dispersed fluorescent silicon nanodots (SiNDs) were synthesized by a one-pot hydrothermal method starting from tetraethyl orthosilicate (TEOS) as silicon source and trisodium citrate as reducing reagent. The method is simple and convenient. The SiNDs, with excitation/emission peaks at 347/440 nm and with fluorescence quantum yield of 18% are shown to be viable fluorescent probes for picric acid (PA). The SiNDs strongly bind PA, and their blue fluorescence is quenched. The distance between the donor and acceptor (R0 value) is calculated from fluorescence data to be 2.1 nm. A fluorometric method was worked out that has a linear response in the 8 nM to 50 μM PA concentration range and a 0.92 nM limit of detection. The method has a fast response (2 min) and is well selective over other nitroaromatic compounds and metal ions. The average recoveries from spiked lake water samples ranged between 98.4 and 100.8%.

    关键词: Nitroaromatic compounds,Picric acid (PA),Fluorometric determination,Tetraethyl orthosilicate (TEOS),Hydrothermal strategy

    更新于2025-09-04 15:30:14

  • Antibacterial and photocatalytic activity of hydrothermally synthesized SnO2 doped GO and CNT under visible light irradiation

    摘要: Bacterial and dye pollution are major problems with wastewater treatment. An increasing number of photocatalysts are being used in industry to kill bacterial and reduce pollution. In the present study, highly stable SnO2-doped nanocomposites have been prepared successively by a hydrothermal method. The synthesized nanocomposite was characterized using a range of techniques, such as X-ray diffraction, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy and electron probe micro analysis, ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, and high resolution transmission electron microscopy (HR-TEM). The nanocomposites showed significant dose-dependent bactericidal activity in the disc diffusion assay and cell viability test. The S-GO-SnO2 200 μg/mL produced a cell viability of 184.3 ± 11.71 and 172.3 ± 3.05 × 106 CFU/mL for E. coli and P. graminis, respectively. The S-GO-SnO2 showed significant photocatalytic degradation against MB in 120 min. The photocatalyst S-GO-SnO2 showed 159 and 161 × 106 CFU/mL at 150 min in E. coli and P. graminis, respectively. The cells treated with photocatalytic SnO2-doped nanocomposites showed 50% cell death. HR-TEM revealed 50% cell growth inhibition by bacterial damage. This photocatalytic SnO2-doped nanocomposite is a good candidate for treating industrial wastewater treatment contaminated with dyes and bacteria.

    关键词: Antibacterial activity,Photocatalytic activity,Hydrothermal syntheses,Visible light irradiation,SGO-SnO2,SCNT-SnO2

    更新于2025-09-04 15:30:14