- 标题
- 摘要
- 关键词
- 实验方案
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Green synthesis of ZnS quantum dot/biopolymer photoluminescent nanoprobes for bioimaging brain cancer cells
摘要: Semiconductor quantum dots (QDs) are one of the most interesting photoluminescent nanomaterials with very promising applications in cancer nanomedicine. In this work, ZnS fluorescent quantum dots (ZnS-QDs) were synthesized and stabilized by carboxymethylcellulose (CMC) as a pH-sensitive biopolymer using a facile one-step green aqueous colloidal process at distinct pH conditions (acidic, neutral and alkaline) and chemical proportions of precursors (Zn2+ and S2?). The optical properties of these nanoconjugates (ZnS@CMC) were characterized by UV–visible and photoluminescence spectroscopy. The morphological features and physicochemical properties were evaluated by TEM, FTIR spectroscopy, zeta potential, and dynamic light scattering (DLS) analyses. The cytocompatibility in vitro of ZnS@CMC was assessed by MTT assay using normal and malignant glioma cells. The UV–Vis results indicated that ZnS-QDs were effectively produced with different bandgap energies (from 4.5 to 3.8 eV) blue-shifted from bulk (Ebulk = 3.61 eV), and sizes (typically from 3.3 to 4.5 nm), dependent on the pH and concentration ratio of precursors during the synthesis. Analogously, the changes of synthesis parameters significantly altered the photoluminescence emission energies and intensities within the visible range of spectra (PL maxima from λ = 400–430 nm, at pH = 3.5, [Zn:S] ratio = 1:2). The cell viability results in vitro (>90%) demonstrated no cytotoxicity of ZnS@CMC nanohybrids towards both cell types. Importantly, these ZnS@CMC nanoconjugates behaved as active fluorescent nanoprobes for bioimaging malignant glioma cells proving the high potential for applications in cancer nanomedicine.
关键词: Fluorescent nanoprobes,Luminescent nanomaterials,ZnS quantum dots,Cancer bioimaging,Green nanotechnology,Luminescent nanoconjugates
更新于2025-09-19 17:13:59
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Plasmon Induced Transparency in Graphene-based Side Coupled two Rectangular Nano-cavities-like structures
摘要: We investigate numerically the plasmon analogue of electromagnetic induced transparency (EIT) in a compact graphene-based waveguide coupled to two rectangular nano-cavities-like structures made out of graphene nanoribbons. The cavities are placed symmetrically on each side of the bus waveguide, giving rise to a V-like state in analogy with three level atomic systems. In this configuration, the cavities are directly coupled to the waveguide, and consequently both play the role of the bright mode. By slightly detuning the Fermi energy level of the cavities, we show the possibility of generating a narrow transparency window, that’s, the plasmon induced transparency (PIT). The resonance peak occurs as a consequence of destructive interference between the cavities acting like coupled radiative oscillators. We also demonstrate that by appropriately shifting (symmetrically) the Fermi energy levels of the cavities, one could dynamically tune the resonance peak frequency. The proposed structure may help the design of highly integrated optical devices.
关键词: Nanomaterials,Plasmon induced transparency,Graphene waveguide,Metamaterials,Surface plasmons
更新于2025-09-19 17:13:59
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Plasmonic nucleotide hybridization chip for attomolar detection: localized gold and tagged core/shell nanomaterials
摘要: We report a large amplification of surface plasmon signals for a double hybridization microarray chip assembly that bridges localized gold and detection probe-carrying-core/shell Fe3O4@Au nanoparticles for detection of as low as 80 aM miRNA-155 marker in solution. The plasmonic wavelength match of the gold shell with surface localized gold nanoparticles and the additional scattering band of the core/shell material in resonance with the incident 800 nm light source are the underlying factors for the observed remarkable analyte signal at ultra-low (10?18 order) concentrations.
关键词: core/shell nanomaterials,nucleotide hybridization,attomolar detection,gold nanoparticles,Plasmonic
更新于2025-09-19 17:13:59
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Industrial Applications of Nanomaterials || Nanotechnology for biological photovoltaics; industrial applications of nanomaterials
摘要: This chapter describes the importance and use of nanotechnology for BPVs. Biological photovoltaics are solar energy conversion systems which are producing electricity based on the photosynthesis reaction takes place in thylakoid membrane. The process of collecting energy from BPV has been studied by the researchers to obtain highly efficient systems. For this reason, number of reports based on the BPVs, which focuses on direct and indirect electricity generation using soluble conductive mediators, has been published. Successful results reveal that these systems can convert sunlight into electricity, but there are some points to increase efficiency. The application of nanomaterials combined with BPV has shown tremendous improvement on the power output of BPV systems. Creating functional surfaces that “wiring” more biological components into the electrode was one of the first steps in nanotechnological advances to BPV systems. Large surface area according to the volume ratio makes anode and cathode electrodes more efficient in applications which is the another main improvement. The potential role of nanomaterials such as carbon nanotube and graphene has been studied with BPV for small and large-scale applications, highlighting the importance and application of green energy production. The electron transport mechanism in cyanobacteria and algae is well known, and the transformation of the newly designed systems into the photovoltaic device by means of nanomaterials with the aid of nanomaterials in the conversion of light into energy has also been shown. The results show that nanotechnology improves the energy conversion rate of BPV systems. It is foreseen that energy exchange rates will increase further with nanomaterial applications and the studies will continue toward industrial applications.
关键词: Nanomaterials,Nanotechnology,Electron transport mechanism,Biological photovoltaics,Photosynthesis,Green energy
更新于2025-09-19 17:13:59
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Industrial Applications of Nanomaterials || Nanomaterials-based UV photodetectors
摘要: Photodetectors are essential elements applied in video imaging, optical communications, biomedical imaging, security, night-vision, gas sensing, and motion detection, which possess the ability to transform light into electrical signals precisely. As the scale and diversity of application areas are growing, the need for innovative photodetection platform technologies with higher performance in terms of speed, efficiency or wavelength range, as well as material flexibility, transparency, and complementary metal-oxide-semiconductor (CMOS) integrability, is becoming more critical. In the past decades, extensive efforts have been devoted to explore the next generation of photodetector materials, such as In2Te3, ZnO, and GaN, with low noise, high photosensitivity, and good stability. However, many of these novel photodetector materials still suffer from limited photocurrent and photoresponse speed.
关键词: Nanomaterials,Schottky contacts,photoconductive gain,photodetection mechanism,photoresistors,linear dynamic range,responsivity,external quantum efficiency,photodiodes,specific detectivity,UV photodetectors
更新于2025-09-19 17:13:59
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Carbon Allotrope-Based Optical Fibers for Environmental and Biological Sensing: A Review
摘要: Recently, carbon allotropes have received tremendous research interest and paved a new avenue for optical fiber sensing technology. Carbon allotropes exhibit unique sensing properties such as large surface to volume ratios, biocompatibility, and they can serve as molecule enrichers. Meanwhile, optical fibers possess a high degree of surface modification versatility that enables the incorporation of carbon allotropes as the functional coating for a wide range of detection tasks. Moreover, the combination of carbon allotropes and optical fibers also yields high sensitivity and specificity to monitor target molecules in the vicinity of the nanocoating surface. In this review, the development of carbon allotropes-based optical fiber sensors is studied. The first section provides an overview of four different types of carbon allotropes, including carbon nanotubes, carbon dots, graphene, and nanodiamonds. The second section discusses the synthesis approaches used to prepare these carbon allotropes, followed by some deposition techniques to functionalize the surface of the optical fiber, and the associated sensing mechanisms. Numerous applications that have benefitted from carbon allotrope-based optical fiber sensors such as temperature, strain, volatile organic compounds and biosensing applications are reviewed and summarized. Finally, a concluding section highlighting the technological deficiencies, challenges, and suggestions to overcome them is presented.
关键词: carbon nanotubes,graphene,sensors,nanomaterials,carbon dots,optical fiber,nanodiamonds,nanocoating
更新于2025-09-19 17:13:59
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Enrichment and Identification of Metallothionein by Functionalized Nano-Magnetic Particles and Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry
摘要: As a low molecular weight protein with the ability of binding metal ions and high inducibility, metallothionein (MT) is often regarded as an important biomarker for assessment of heavy metal pollution in water environment. In the light of that the traditional process of enrichment and identification is time-consuming and complicated, we prepared a core-shell nanoparticle, gold-coated iron oxide nanoparticles (Fe3O4@Au NPs) herein. It possessed the advantages of fast response to magnetic fields and optical properties attributing to Fe3O4 and Au nanoparticles, respectively. The Fe3O4@Au nanoparticles could be used to enrich MT simply through Au–S interaction, and the purified proteins were determined by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS). The results showed that the Fe3O4@Au nanoparticles could directly enrich MT from complex solutions and the detection limit could be as low as 10 fg mL?1.
关键词: Core-shell structure,Mass spectrometry,Low-abundant,Metallothionein,Gold nanoparticles,Magnetic nanomaterials
更新于2025-09-19 17:13:59
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Laser-induced graphene and carbon nanotubes as conductive carbon-based materials in environmental technology
摘要: Nanotechnology and nanomaterials have attracted interest due to their potential in mitigating contemporary environmental challenges, such as the stressors imposed by increased industrial and agricultural activities, and the deterioration of air, soil and water quality. In particular, advanced technologies that harness carbon-based nanomaterials are poised to emerge as tools that provide new solutions for the global water crises. These tools include, electrically conductive membrane processes, which uniquely combine a separation process with a functional surface. In this respect, laser-induced graphene (LIG) and carbon nanotubes (CNTs) are electrically conductive carbon nanomaterials that hold great utility in a multitude of environmental applications, including the development of fouling-resistant systems for desalination and water treatment, enhanced separation methods, and innovative pollutant sensing and electrocatalytic platforms. Consequently, this review article describes and compares some important recent advances in LIG- and CNT-based electroactive surfaces. The discussion of LIG as an emerging carbon material set in context with CNTs is intended to shed light on future directions and development possibilities to meet the growing global challenges in terms of water treatment applications of both materials as well as other electrically conductive carbon-based nanomaterials exhibiting exceptional performance and versatility.
关键词: environmental applications,nanomaterials,electrically conductive membrane processes,laser-induced graphene,Nanotechnology,water treatment,carbon nanotubes,carbon-based nanomaterials
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Effect of tapered fiber structure on the PbS Nanomaterials optical fiber amplifier excited by evanescent wave
摘要: PbS nanomaterials fiber amplifier was fabricated by coating PbS nanomaterials onto tapered fiber. PbS is deposited by atomic layer deposition technique. The influence to optical properties is discussed when changing the structure of tapered fiber.
关键词: optical fiber amplifier,atomic layer deposition,PbS nanomaterials,tapered fiber
更新于2025-09-16 10:30:52
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Effect of nanostructured metal oxides (CdO, Al2O3, Cu2O) embedded in PVA via Nd:YAG pulsed laser ablation on their optical and structural properties
摘要: The physiochemical properties of Polyvinyl Alcohol (PVA) film was enhanced by embedding with nanostructured metal oxides (CdO, Al2O3, and Cu2O) via one-pot and green method, nanosecond Nd:YAG pulsed laser ablation in liquids technique (PLAL). This process was carried by ablation of metal targets (cadmium, copper, and aluminum) immersed in PVA solution by high intensity pulsed laser in the focusing condition. The enhancing of the PVA properties were appeared by studying the structure, optical and morphology of the prepared films before and after embedding by several technique as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–Visible, Photoluminescence (PL), Scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). From structural investigation, the XRD patterns showed a reduction of CdO, Al2O3, and Cu2O nanoparticles within PVA chain. From optical investigation, the interaction and the structural modifications occurred between PVA chains and each metal oxide nanoparticles appeared in stretching vibration bands, the optical energy band gap (Eg) values by using Tauc equation equaled to 2.33, 3.63, and 3.54 eV for the oxide of Cd, Al, and Cu, respectively, are a good agreement with previous work, and the Photoluminescence spectra showed decreasing in emission intensity in the case of embedding with metal oxides. From morphological investigation, the FE-SEM images showed a homogeneous distribution with spherical shape of metal oxides through the polymer of PVA. The qualitative and semi-quantitative elemental analysis of the prepared samples via EDX technique confirmed the embedding of the metal oxide in the PVA structure. This work helps to open the route to produce various properties of PVA by embedded with different nanostructured metal oxides.
关键词: Laser ablation,Al2O3,Nd:YAG,Metal oxides,nanosecond,PVA,Nanomaterials,CdO,Cu2O
更新于2025-09-16 10:30:52