Quantum Nano Research Articles

Citrus limon peel-based biosynthesis: Lead oxide, zinc oxide, cadmium oxide, and copper oxide nano quantum dots for subtraction of anionic Actas Pink dye (AAPD)

ABSTRACT Adsorption is a highly effective method for wastewater quality adjustment, offering advantages such as low cost and availability of adsorbents. This study investigates the efficient removal of Anionic Actas Pink dye (AAPD), a major contributor to environmental pollution. Green adsorbents including lead oxide (PbO), zinc oxide (ZnO), cadmium oxide (CdO), and copper oxide (CuO) were synthesized via eco-friendly routes for AAPD removal. Maximum adsorption capacities (qe) were observed at pH 7 (PbO, ZnO, CdO) and pH 2 (CuO and native) with values of 83.83 mg/g at 100 ppm, 75.65 mg/g at 100 ppm, 70.50 mg/g 75 ppm, 61.21 mg/g at 150 ppm, and 52.69 mg/g at 150 ppm, respectively, using an adsorbent dose of 0.05 g/50 mL at temperature of 37°C, and 90 min contact time. Adsorption followed Langmuir isotherm for all adsorbents except native, with PbO also fitting Freundlich and Dubinin–Radushkevich isotherms. Kinetics adsorption data supported pseudo-second-order, while thermodynamic analysis indicated spontaneous and exothermic nature. Effects of electrolytes, surfactants, and desorption were also evaluated. Characterization through FTIR, SEM, and XRD confirmed the morphology and functional groups of these nano-quantum dots. Citrus limon peel-based biosynthesis offers sustainable, eco-friendly, and cost-effective alternatives, highlighting their potential for dye adsorption.

Studying the Synchronization for Multiple Transmitter- Receiver Nano Quantum Cascade Lasers.

In this paper, the chaos synchronization of four Nano quantum cascade lasers with optoelectronic feedback was investigated. The present system consists of two receiver lasers and two transmitters lasers. The rate equation model was modulated to study the effect of the Purcell factor F and the spontaneous emission factor because of their importance in a nanocavity. The results indicated that the suggested system, realize the chaos synchronization. Also, the nanocavity parameters F and β, have significant effect on the chaos synchronization quality and may lead to lose it. Furthermore, the results showed the weak effect of delay time on the performance of lasers.

Separated Electron-Phonon and Phonon-Phonon Scatterings Across Interface in Thin Film LaCoO3 /SrTiO3.

Electron-phonon coupling (EPC) and phonon-phonon scattering (PPS) are at the core of the microscopic physics mechanisms of vast quantum materials. However, to date, there are rarely reports that these two processes can be spatially separated, although they are usually temporally detached with different characteristic lifetimes. Here, by employing ultrafast spectroscopy to investigate the photo-carrier ultrafast dynamics in a LaCoO3 thin film on a (100) SrTiO3 substrate, intriguing evidence is found that the two interactions are indeed spatially separated. The EPC mainly occurs in the thin film, whereas PPS is largely in the substrate, especially at the several atomic layers near the interface. Across-interface penetration and decay of optical phonons into acoustic phonons thus naturally occur. An EPC strength λEg =0.30 is also obtained and an acoustic phonon mode at 45.3GHz is observed. The finding lays out a cornerstone for future quantum nano device designs.

Effect of Transition Metal (Fe, Co) Ion Doping on TiO2 Nano Particles.

Keywords: Growth from solution, Nanomaterials, Oxides, Photocatalytic, Sol-Gel method, DMS. . we report the growth of [Fe, Co]xTiO2 (x=0.01, 0.02 & 0.04) Nano quantum dots prepared by Sol-Gel technique, followed by freeze-drying treatment at -30°C temperature for 12hrs. The obtained Gel was thermally treated at different temperature like 200,400,600, 800°C. The crystalline size of 4 to 40 nm is achieved. X-ray diffraction pattern of samples show anatase phases of TiO2, up to 600°C. At 800°C, the phase is Rutile. Figure 1 shows the XRD patterns acquired from different samples heated at different temperatures. The diffraction peak at 25.22°, 25.49°and 25.6° observed from the XRD pattern of the Fe, Co doped TiO2 shows that the main crystal phase is anatase, and the peak at 27.47° indicates the presence of the rutile phase. All the peaks in the XRD patterns of the sample calcined at 200°C, 400°C and 600°C of TM doped TiO2 can be designated to the anatase phase (most active phase) without any indication of other crystalline phases such as rutile or brookite . As a variant valence metal cation, Fe, Co ions can react with Ti4+ on the surface of TiO2, and Ti4+ is reduced to Ti3+ which inhibits the transformation of anatase to rutile [1]. It leads to the reduction in the oxygen vacancies on the TiO2 surface and suppresses the crystallization of other phases by adsorbing onto the surface of the TiO2 particles [2]. The photocatalytic degradation of formaldehyde has been successfully demonstrated using a 250 V UV lamp with TM doped TiO2 nano powder in a specific experimental setup. The degradation rate increases linearly with dopant content increases. This indicates that the photocatalytic reaction in this experiment was effected by dopant concentration. The results obtained in this research contribute to the understanding of binary doped transition metal ions in TiO2 nanoparticles can lead the efforts of enhancing their environmental application. Study of Magnatic proprty has been carried out by using VSM. The magnetic susceptibility of the Fe, Co doped TiO2 nanopowder increases with increase in doping concentration. Fe, Co doped TiO2 exhibits ferromagnetism at room temperature. Figure 1

Nano Quantum Computing thin films electronic components to act as rectifier and amplifier in simulation theory

There is an urgent need for cheap, high capacity, and high-speed electronic chips. This needs using Nano electronic components which obey quantum laws. Using Schrodinger equation, the solution for Nano rectangular plates or medium shows the possibility of rectifying and amplifying the electric current. When one fuses two rectangular metallic plates with one have dimensions less than a critical value while the dimension of the other is more than this critical value, one can rectify the electric current. It is also possible to rectify the electric current when two mediums are fused together. One must have an internal potential greater than a certain critical value, while the potential of the other is less than this critical value. Current amplification is possible also when the medium potential is less than the same critical value.

Hydrothermal synthesis and their ethanol gas sensing performance of 3-dimensional hierarchical nano Pt/SnO2

A hierarchical SnO2 nanosheet structure was constructed by the hydrothermal method using hydrated stannous chloride and thiourea as raw materials. Then lysine was used as a coupling agent to load Pt nano quantum dots with different contents on the surface of the SnO2 nanosheets. The composition, morphology and structure of Pt/SnO2 were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy and energy dispersive spectroscopy. The gas sensitivity of the Pt/SnO2 and SnO2 nanostructures were also studied in detail. Compared with the pure SnO2 nanosheets, the 3-dimensional structured nano 2.0% Pt/SnO2 (Pt: SnO2 = 2.0%, wt%) exhibits a higher gas sensitivity to ethanol gas at 240 °C. The gas sensitivity to 100 ppm ethanol of hierarchical nano 2.0% Pt/SnO is 2.5 times higher than pure SnO2 nanosheet, and the response time and recovery time are 4 s and 5 s, showing excellent response and recovery behavior. Meanwhile, the sensor also exhibits a lower detection limit of 0.272 ppm, as well as the excellent temperature and time stability. The higher gas sensitivity is contributed from the "spillover" effect of Pt nano quantum dots and the Schottky barrier at the heterojunctions of hierarchical Pt/SnO2 nanostructures.

New radiation therapy for cancer using monochromatic X-rays and nanoparticles

There are longstanding research efforts to improve treatments for cancers. Two treatment options are chemotherapy and radiation therapy but there is room for improvement and researchers at the Institute for Advanced Study, Kyoto University, Japan, have developed a new method that could lead to the development of a new type of cancer radiation therapy and save lives. The research team is led by Professor Fuyuhiko Tamanoi who is principal investigator at the Tamanoi Laboratory at Kyoto University and leader of the Quantum Nano Medicine Research Center. The method involves generating a cloud of electrons inside a cancer cell that causes DNA breaks, which has potential to eliminate cancer cells. This approach is built on the Auger effect which postulates that when high Z elements are irradiated with monochromatic X-rays, the energy from the X-rays are absorbed by the K-shell electron, which leads to the release of multiple electrons, which have the capability to produce DNA double strand breaks. To achieve the necessary conditions, the team used nanoparticle design combined with state-of-the-art X-ray technology. The team is also developing a new type of nanoparticle called Biodegradable periodic mesoporous organosilica (BPMO), which is a type of mesoporous silica nanoparticles (MSN).

Investigation the dynamic of nano quantum cascade lasers with optoelectronics feedback


 
 
 
 In this paper, a theoretical investigation of negative optoelectronic feedback study in Nano quantum cascade lasers is presented. The present rate equation model has been modified to include the nano laser factors such as the Purcell factor and the spontaneous emission factor. The results indicate that the present rate equation model can be using to study the effect of Purcell factor and the spontaneous emission factor on the negative optoelectronic feedback in Nano quantum cascade lasers. It is found that the increase in Purcell factor value leads to increase in photon number and decrease the carrier number in all quantum states. Also, the dynamic of photon number (S) tends to stable at constant value with the increase of Purcell effect i.e. there is small variation in photon number and carrier number( , , ). The decreases in enhanced spontaneous emission factor value leads to increases in carrier number and decreases the photon number and we note small variation in these values.
 
 
 

Review article multiplex protein detection: A novel approach using nano quantum dots (CD)

Abstract Incorporate into a multiplex quantization of 3-various cancer markers, cancer antigen 125 (CA125), carcino embryonic antigen (CEA), and Her-2/Neu (C-erbB-2) can be conziable by integration of semiconductor nano molecule quantum dots (QDs) into modularity, micro-fluidic bio-sensor. The practicality of integrated specimen processing and detection modalities can be entire using serum and whole saliva specimens. Applying the sandwich-type immuno-test approach, nano-bio-chips can likewise be create utilizing By miniaturized scale permeable agarose, fluorescence transduction signal with QD named investigate counter acting agent in blend with antigen catch globule cluster upheld inside a small scale fluidics group. Utilize of QD probes in this miniaturized bio-sensor format can result in better detections when compared to that of standard molecular fluoro-phores and “Enzyme Linked Immuno Sorbent Assay (ELISA)”. By nano-bio-chip system Assay validation studies indicate that measurements correlate with norms methods. For important diagnostic experiment, to be a sensitive case of medical this unified nano-bio-chip assay system, multiplexed tool especially in the field of cancer.

Topological edge states at single layer WSe2 1T′–1H lateral heterojunctions

Transition metal dichalcogenides can be epitaxially grown at the single layer limit, which also adopt a variety of structural polymorphs with significantly different electronic properties. Lateral heterostructures of different polymorphs can be further synthesized for emergent functionality. Here, we selectively grow semiconducting 1H and metastable 1T′ phases of WSe2 on epitaxial graphene/SiC(0001) by molecular beam epitaxy and further show that the 1T′ phase is a two-dimensional topological insulator. Using angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy, we determine that 1T′–WSe2 exhibits a large bulk bandgap of 120 meV, and edge states at the 1T′–1H lateral heterojunction extend within 1.6 nm from the heterointerface at the 1T′ side. These edge states are robust and persist regardless of the fact that if the edge is (1 × 1) zigzag or (3 × 1) reconstructed, confirming their topological nature. This further facilitates the epitaxial growth of 1T′–1H lateral junction superlattices with multiple helical edge channels, underpinning ultrahigh-density 2D topological nano quantum devices.

The effects of lead–ring coupling and the external Rashba interaction on the effective spin polarization of a chain of quantum nano rings

The effective spin polarization and spin filtering of a linear chain of N one-dimensional nanorings in the presence of the Rashba and Aharonov–Bohm effects are studied by considering three different lead–ring coupling regimes. Utilizing the transfer-matrix method, the optimal number of rings for maximizing the system efficiency is determined in the weak, medium, and strong lead–ring coupling regimes. The strong coupling regime is proposed for the design of spintronic devices as it exhibits the highest system efficiency. Furthermore, by tuning the Rashba strengths in the rings alternately, perfect spin filtering and full-range spin polarization with high efficiency can be obtained in narrow ranges of the incident electron wavenumber. Moreover, controlling the Rashba strength leads to the design of energy-filtering devices with a desired spin polarization, which could play a dominant role in spintronic technology.

Preparation of cellulose insulating paper of low dielectric constant by OAPS grafting

This study aims to decrease the dielectric constant of cellulose insulating paper by octa(aminophenyl)silsesquioxane (OAPS) grafting. OAPS was grafted onto the primary hydroxyl group of cellulose molecules via amino groups and epichlorohydrin. The dielectric constant and dielectric loss of insulating paper before and after modification were investigated. Relative to the unmodified paper, the dielectric constant of 15 wt% OAPS-grafted paper decreased from 5.27 to 4.28, and the dielectric loss decreased by 37.5% at 50 Hz. The movement and orientation polarization of the cellulose chains could be restricted due to the porous macromolecular structure and nano quantum interface effect produced by OAPS, thereby resulting in the reduction of cellulose polarizability. Moreover, the OAPS grafting modification does not degrade the other properties of cellulose insulation, i.e., its thermal stability, mechanical performance, fire-resistant properties, and electrical strength. OAPS grafting has promising potential application for preparing low dielectric constant insulating paper.

Optical Absorption and Photoluminescence in the Spherical InP/InSb/InP Core/ shell/ shell Nano Structure

The one particle states of charge carriers are considered in InP/InSb/InPcore/shell/shell spherical quantum nano structure at the regime of strong quantization. The results of numerical calculations for the values of the energy of charge carriers for different values of the thickness of the quantizing layer of InSb are presented. The calculations were performed with allowance for the Kaned is persion for electrons and light holes in the InSb layer. The dependence of the number and position of the energy levels of charge carriers in the quantizing layer of InSb on the width of the well (layer thickness) is shown. The dependence of the absorption coefficient and photoluminescence spectra on the energy of incident light of interband transitions have been investigated. The oscillator strengths and selection rules for these transitions have been obtained. The absorption has a strictly resonant character. By the orbital and azimuthal numbers only diagonal inter band transitions are possible. For the radial number, the transitions between the states with the same radial numbers have the highest intensity

Quantum nano ring composed of quantum dots as a source of pure persistent spin or charge current

Spin-dependent persistent current in a quantum ring constituted by two normal and one magnetic quantum dots, in the presence of Rashba spin–orbit interaction is studied by using Green function technique. It is shown that the presence of the magnetic quantum dot breaks the degeneracy of the density of states of electrons with different spin states. Besides, the Rashba spin–orbit interaction along with the magnetic quantum dot develops tunable persistent spin and charge currents. Moreover, the persistent charge current induces a fully adjustable magnetic flux whose direction and magnitude can be tuned by altering the strength of the Rashba spin–orbit interaction.

TMIC-01TUMOR TARGETED QUANTUM DOTS TO IDENTIFY GLIOMA INITIATING CELLS AND EXOSOMES

TUMOR MICROENVIRONMENT TMIC-01. TUMOR TARGETED QUANTUM DOTS TO IDENTIFY GLIOMA INITIATING CELLS AND EXOSOMES Achutha Madhankumar, Oliver Mrowczynski, Suhag Patel, Elias Rizk, Cody Weston, Michael Glantz, Lichong Xu, Christopher Siedlecki, and James Connor; Pennsylvania State University College of Medicine, Hershey, PA, USA GBM and certain brain metastatic cancers possess invasiveness and high infiltrating potential making them harder to detect at the earlier stage of the disease progression. Identification of cancer stem cells and exosomes secreted by them in the biofluids like CSF will be an ideal way to determine the presence of residual cancer after therapy. We utilize ligand conjugated quantum dots (QD) to specifically label the cancer stem cells and exosomes to identify the presence of certain invasive markers. Human glioma initiating cells were cultured in adherent form and were exposed to interleukin-13 conjugated quantum dots (IL13QD), which binds the glioma initiating cells expressing IL13Ra2 receptor and also the exosomes secreted by the glioma stem cells. Exosomes that were isolated from glioma stem cells and patients CSF were demonstrated to express IL13Ra2 receptor. Fluorescent microscopy, electron microscopy and flow cytometry were performed on the exosomes after complexing with nano quantum dots (QD). IL13QD was demonstrated to specifically bind glioma stem cells both in the monolayer and spheroid culture. The binding affinity of the exosomes to the quantum dots were also confirmed by atomic force microscopy. The morphology and size of exosomes were confirmed by electron microscopy and dynamic light scattering method. The density plot from the flow cytometer experiments with IL13QD-exosomes complex indicates a possibility to identify the tumor associated exosomes. Our experiment infers that in ex vivo, tumor targeted quantum dots can bind with tumor initiating glioma stem cells and extracellular vesicles (exosomes) that are secreted by cancer cells. There is a future possibility to differentiate the metastatic tumor associated exosomes from the non-metastatic exosomes based on their QD binding profile Neuro-Oncology 17:v221–v225, 2015. doi:10.1093/neuonc/nov236.1 Published by Oxford University Press on behalf of the Society for Neuro-Oncology 2015.

Excitons in a quasi-one-dimensional quantum nanorod under a strong electric field

The response of an exciton in the ground and first excited states to a strong DC electric field is studied in a quasi-one-dimensional nano quantum well (i.e., nanorod) bounded by high symmetric barriers by studying the energy, the oscillator strength, the root-mean-square (RMS) average of the electron-hole (e-h) separation, and the average positions of the electron and the hole. The interplaying effect between the barrier confinement, e-h attraction, and the field-induced e-h separation for exciton binding is examined. We find that, for a long nanorod, the exciton energy, as well as, the oscillator strength drops abruptly as a function of the field near the exciton-dissociation field while the RMS average of the e-h separation rises rapidly. For shorter rods, the transition is more gradual due to the combined effect of the confinement and the long-range e-h interaction. A strong field is shown to transform the optically-inactive first excited state into an optically-active state in the field range between the dissociation field of the ground state and that of the first excited level. We also find that, in the ground state, the (lighter) electron is dragged by the (heavier) hole below the dissociation field. The dependence of the above mentioned properties on the rod length is also investigated for varying fields. The results are compared with those obtained for the rods with parabolic confinement.

Beltrami fields at nanoscales in a quantum electron-hole plasma

The self-organization of electron-hole quantum plasmas is described. It is shown that steady state equilibrium is governed by a triple curl Beltrami field which is a superposition of three Beltrami fields. The results show the possibility of creating Beltrami fields of the order of nanoscale size. It is also shown that pressure gradients exist in the relaxed state and can be confined by a generalized Bernoulli mechanism. Our results are of strong relevance to quantum nano devices.

Synthesis of highly fluorescent and thio-linkers stabilize gold quantum dots and nano clusters in DMF for bio-labeling

This study demonstrates a one versus two-step synthesis of fluorescent gold quantum dots (F-AuQDs) and nano clusters (F-AuNCs) functionalized with thiolated organic linkers using reduction of gold precursor in N,N′-dimethylformamide in 1 h of reaction. The F-AuQDs and F-AuNCs show fluorescence emission at 425 ± 5 nm upon excitation at 345 ± 5 nm of wavelength, with good water solubility and stability. Five different thiolated organic binary linkers consisting of various functional groups including: carboxylic acid, hydroxyl, and aromatic amine, were conjugated with the F-AuQDs and F-AuNCs. The formation mechanism and functionalization of the F-AuQDs and F-AuNCs was characterized using UV–vis absorption spectra, UV–vis light, fluorescent emission spectra, pH, TEM, and FTIR. The fluorescence emission of the F-AuQDs and F-AuNCs is greatly dependent on the thio-linker. This novel one-step approach provides facile and fast synthesis of F-AuQDs and F-AuNCs over the two-step method, with less than 5 h of reaction and workup compared to more than 28 h of reaction for the two-step approach. These thio-linker functionalized F-AuQDs and F-AuNCs have a wide application in fluorescent labeling of biomolecules, optical devices, imaging, energy transfer, and biosensing.

Self‐organized growth of ZnO‐based nano‐ and microstructures

AbstractZnO‐based nano‐ and micro‐structures with controlled orientation, size, and lateral density were grown by specially designed two‐step pulsed laser deposition and direct carbothermal growth, respectively. Different substrate orientations and nucleation layers allow well‐defined tuning of growth direction and lateral arrangement of the wires. As a result, axial MgZnOZnO nano quantum dots and homogeneous radial nano core‐shell quantum well structures are demonstrated. Donor and acceptor doping of nano‐ and microwires influence considerably both electrical characteristics as well as morphology including branching. Field effect transistors with n‐ and p‐type wire channel and nanowire p–n junctions seem to prove a reproducible p‐type conductivity of phosphorous‐doped ZnO wires. Single ZnO wire (309 nm thick, 3.99 µm high) grown on pyramidal base with controlled lateral density by tuning the ZnO template layer in a two‐step PLD process. magnified image

Heavy Ion Tracks Route to Nanotechnology

Heavy ion tracks recorded in dielectric materials were found to have a width of 5-10 nm using SEM. Heavy ion beams were used for irradiation of Polymers and Muscovite mica to create Ion Track Filters (ITFs) using UNILAC facility at Darmstadt, Germany. The electrochemically etched pores of ITFs used would act as a template. The simple principle of electroplating is used to create heterostructures. The rate of deposition of metallic film depends upon current density, inter-electrode distance, cell voltage, electrolyte concentration and temperature etc. The use of ITFs looks quite promising in the fabrication of micro and nanostructures. The morphology of such structures produced through electrochemical methods and replicas of etched tracks in ITFs have been investigated in detail. The efficacy of the technique was tested for growth of quantum dots, fibers, cones, whiskers, micro and nano wires. A 3-dimensional ensemble of Cu-Se was grown electrochemically using ITF of Makrofol-KG. Replication of etched pores in ITFs has been used to develop microtubules. Presently, we are engaged to develop quantum dots, nanorods and nanowires of copper, iron and bismuth using Anodic Alumina Membranes (AAM), Polycarbonate ITFs and Reverse Micelle technique. The preliminary results of our investigations will be presented at NADPA-2008.