- 标题
- 摘要
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- 实验方案
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The synthesis of carbon-based nanomaterials by pulsed laser ablation in water
摘要： Pulsed Laser Ablation in liquid (PLAL) is considered as a robust and simple technique for producing nanoparticles (NPs) using lasers. The carbon-based nanoparticles were fabricated via the PLAL approach by irradiating a graphite target with a pulsed Nd:YAG laser of wavelength 532 nm. The graphite target was immersed in distilled water and irradiated for 10 min. The pulse length, reputation rate, and ?uence were 6 ns, 10 Hz, and 0.4 J cm?2, respectively. The structural and physical properties of the synthesized NPs were investigated and analyzed using different characterization methods. For example, Transmission Electron Microscopy (TEM) images revealed diverse carbon nanostructures such as graphene nanosheets, nanospheres, nanospheres in the shape of a necklace, and nanotubes. The spectrum of Energy Dispersive X-Ray spectroscopy (EDX) con?rmed successful synthesis of high purity carbon nanostructures. Moreover, the result of X-Ray Diffraction (XRD) Spectroscopy indicated the presence of reduced Graphene Oxide (rGO) with a (002) plane and the absence of Graphene Oxide (GO). The transmission spectrum from Ultraviolet-Visible (UV–vis) analysis showed a strong trough at 266 nm which is attributed to the presence of carbon nanostructures. Furthermore, Fourier-Transform Infrared Spectroscopy (FTIR) analysis demonstrated the vibration bonds related to carbon. The nanostructures produced were semi-stable with little agglomeration as was inferred from the results of the Zeta Potential. Finally, the Dynamic Light Scattering (DLS) analysis supported the TEM results. PLAL technique is proved to be a simple method for producing carbon-based nanomaterials. Moreover, the laser ?uence was found to be an important factor which affects greatly the type of nanostructures that could be synthesized during laser ablation.
关键词： reduced graphene oxide,graphene,carbon-based nanomaterials,pulsed laser ablation
更新于2025-09-12 10:27:22
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Industrial Applications of Nanomaterials || Laser-driven nanomaterials and laser-enabled nanofabrication for industrial applications
摘要： Laser is one of the most important technologies invented in the 20th century. Nowadays, the applications of laser have stretched over a vast spectrum including information technology, optoelectronics, quantum computing, materials characterization, materials processing, advanced three-dimensional (3D) printing, biology, biomedical, etc. In the nanotechnology domain, laser can be used for synthesis, processing, and characterization. In this chapter, we will focus on applying laser for synthesis and processing of nanomaterials as well as nanofabrication.
关键词： nanofabrication,nanomaterials,laser ablation,laser pyrolysis,Laser,carbon-based nanomaterials,industrial applications
更新于2025-09-11 14:15:04
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Fluorometric determination of aflatoxin B1 using a labeled aptamer and gold nanoparticles modified with a complementary sequence acting as a quencher
摘要： A fluorometric aptamer based assay is described for rapid and sensitive detection of aflatoxin B1 (AFB1). It is making use of a fluorescein (FAM) labeled anti-AFB1 aptamer and complementary DNA-modified gold nanoparticles (GNPs). In the absence of AFB1, the FAM-labeled aptamers hybridize with complementary DNA strands that were covalently immobilized on GNPs. This results in quenching of the green fluorescence (with excitation/emission peaks at 485/525 nm). In the presence of AFB1, the aptamer probe binds AFB1 and is released from the GNPs. Hence, fluorescence is restored. Under optimized conditions, AFB1 in the concentration range from 61 pM to 4.0 μM can be detected, and the detection limit is 61 pM. This assay is highly selective for AFB1. It was applied to the determination of AFB1 spiked into 50-fold diluted wine and 20-fold diluted beer.
关键词： Mycotoxin,Food safety,Environmental analysis,Fluorescence quenching,Fluorophore,Fluorescent probe,Nanomaterials,Nanoprobe
更新于2025-09-11 14:15:04
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Nanomaterial‐Enabled Flexible and Stretchable Sensing Systems: Processing, Integration, and Applications
摘要： Nanomaterial-enabled flexible and stretchable electronics have seen tremendous progress in recent years, evolving from single sensors to integrated sensing systems. Compared with nanomaterial-enabled sensors with a single function, integration of multiple sensors is conducive to comprehensive monitoring of personal health and environment, intelligent human–machine interfaces, and realistic imitation of human skin in robotics and prosthetics. Integration of sensors with other functional components promotes real-world applications of the sensing systems. Here, an overview of the design and integration strategies and manufacturing techniques for such sensing systems is given. Then, representative nanomaterial-enabled flexible and stretchable sensing systems are presented. Following that, representative applications in personal health, fitness tracking, electronic skins, artificial nervous systems, and human–machine interactions are provided. To conclude, perspectives on the challenges and opportunities in this burgeoning field are considered.
关键词： sensing systems,human-machine interfaces,nanomaterials,Flexible electronics,health monitoring,stretchable electronics
更新于2025-09-11 14:15:04
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Mixed Lead Halide Passivation of Quantum Dots
摘要： Infrared-absorbing colloidal quantum dots (IR CQDs) are materials of interest in tandem solar cells to augment perovskite and cSi photovoltaics (PV). Today’s best IR CQD solar cells rely on the use of passivation strategies based on lead iodide; however, these fail to passivate the entire surface of IR CQDs. Lead chloride passivated CQDs show improved passivation, but worse charge transport. Lead bromide passivated CQDs have higher charge mobilities, but worse passivation. Here a mixed lead-halide (MPbX) ligand exchange is introduced that enables thorough surface passivation without compromising transport. MPbX–PbS CQDs exhibit properties that exceed the best features of single lead-halide PbS CQDs: they show improved passivation (43 ± 5 meV vs 44 ± 4 meV in Stokes shift) together with higher charge transport (4 × 10-2 ± 3 × 10-3 cm2 V-1 s-1 vs 3 × 10-2 ± 3 × 10-3 cm2 V-1 s-1 in mobility). This translates into PV devices having a record IR open-circuit voltage (IR Voc) of 0.46 ± 0.01 V while simultaneously having an external quantum efficiency of 81 ± 1%. They provide a 1.7× improvement in the power conversion efficiency of IR photons (>1.1 μm) relative to the single lead-halide controls reported herein.
关键词： ligand exchange,infrared photovoltaics,quantum dots,nanomaterials
更新于2025-09-11 14:15:04
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DNA‐Functionalized Plasmonic Nanomaterials for Optical Biosensing
摘要： Plasmonic nanomaterials, especially Au and Ag nanomaterials, have shown attractive physicochemical properties, such as easy functionalization and tunable optical bands. The development of this active subfield paves the way to the fascinating biosensing platforms. In recent years, plasmonic nanomaterials–based sensors have been extensively investigated because they are useful for genetic diseases, biological processes, devices, and cell imaging. In this account, a brief introduction of the development of optical biosensors based on DNA-functionalized plasmonic nanomaterials is presented. Then the common strategies for the application of the optical sensors are summarized, including colorimetry, fluorescence, localized surface plasmon resonance, and surface-enhanced resonance scattering detection. The focus is on the fundamental aspect of detection methods, and then a few examples of each method are highlighted. Finally, the opportunities and challenges for the plasmonic nanomaterials–based biosensing are discussed with the development of modern technologies.
关键词： optical,nanomaterials,plasmonic,DNA-functionalized,biosensing
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Anti-Stokes Cryoluminescence in Nanomaterials
摘要： Study of the electromagnetic fields interaction with structured nanomaterials with photonic band gaps is one of the most rapidly developing areas of nanophotonics. In modern optics, such nanomaterials are actively used to process the characteristics of electromagnetic radiation. Firstly, the properties of amplification of the local field are used, secondly, the properties of the photonic bandgap. A typical example of local field amplification is the work [1], in which the authors used a coating of submicron dielectric spheres on a copper target in order to achieve more than tenfold increasing the efficiency of X-ray generation. Using the properties of the photonic band gap leads to the increasing well-known nonlinear effects efficiency and to the appearance of new nonlinear phenomena. One of these phenomena is anti-Stokes cryoluminescence in nanomaterials - light emission at low temperature under laser action in the spectral range with higher frequency than that of exciting light. We observed bright and long (up to few seconds) emission in blue-green range under 20ns ruby laser pulses excitation in different nanomaterials at low temperatures [2-3]. One of the reasons of this effect is triboluminescence, free radicals appearing and structure defects forming, like in bulk materials [4]. In the present work we show that in nanomaterials of different nature there are two types of temporal dependence: short (few microseconds) and long (up to 10-12 seconds). Long dependence exists at temperatures lower than 110 K. Temporal dependence for anti-Stokes luminescence in synthetic opal matrices for temperatures lower and higher this threshold is shown in Figure 1.
关键词： anti-Stokes cryoluminescence,nanophotonics,electromagnetic radiation,photonic band gaps,nanomaterials
更新于2025-09-11 14:15:04
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Light absorption enhancement of plasmonic based photo-detector with double nanograting structure
摘要： This era of high speed photonic systems demands photo detectors to have large bandwidth, gain and improved light enhancement competence. Amongst the different light absorption enhancement methods being researched by the investigators, plasmonic has acquired increased attention in the last decades. Although single layer plasmonic supported metal semiconductor metal photo detector has been explored for higher light absorption efficiency, but exploration for double layer structure is lacking in literature. This paper presents performance of plasmonic based photodetector with double layer of nanogratings optimized at wavelength of 1.4 μm for night vision applications. Proposed design of plasmonic supported photodetector with double nanograting reports quenching factor of 92.14% and provides highest light enhancement with subwavelength aperture height of 60 nm. This can be credited to fact that both top and bottom layer of grating contributes to light trapping.
关键词： Surface plasmon polaritons (SPPs),Nanogratings,Nanomaterials,Plasmonics,Subwavelength aperture
更新于2025-09-11 14:15:04
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Selected Scattering on Quasi-Ordered Hexagonal Close-Packed Al Nanodents for Tunable Output of White LEDs
摘要： Quasi-ordered hexagonal close-packed Al nanodents, with depths of 30 nm and top-diameters of 300 nm prepared by electrochemical anodizing, are used to manage the output spectrum of white Light Emitting Diodes (LEDs). Signi?cant short wavelength light, with a peak of 450 nm, displays signi?cant scattering enhancements on these Al nanodents with the increment of the angle of the incidence, while long wavelength light, with a peak of 550 nm, shows weaker scattering on Al nanodents with the increment of theincidence angle. Near-?eld and far-?eld simulations reveal the e?ect of light coupling in the holes of Al nanodents on the selected scattering. This work could provide a striking new way to make use of cheap white LEDs.
关键词： Al nanodents,nanomaterials,selected light scattering,white LED
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE Photonics Conference (IPC) - San Antonio, TX, USA (2019.9.29-2019.10.3)] 2019 IEEE Photonics Conference (IPC) - An Investigation on Stable and Continuous Operation of Hybrid Perovskite Quantum Dot Light Emitting Diodes
摘要： Two different package structures of hybrid perovskite quantum dots light emitting diodes were demonstrated with stable and continuous light emission. With boron nitride nanoparticles, the lifetime of device is expected to be thousands of hours.
关键词： Nanomaterials,Quantum-dot devices,Light-emitting diodes
更新于2025-09-11 14:15:04