Applied Nanoscience最新文献

Tumors are significant diseases that pose a substantial threat to human health. Presently, there are diverse methods for diagnosing and treating tumors in clinical. However, real-time monitoring of the distribution of tumor cells within the body and precise tumor eradication remains a challenge. Recently, with the advancement of nanotechnology, the utilization of nanoparticle has enabled real-time monitoring of tumor cells migration and distribution within the body, as well as controlled and sustained drug release tailored to the specific tumor microenvironment (TME). This achievement has facilitated precise tumor eradication. Among various nanoparticle, graphene oxide (GO) boasts a substantial-specific surface area, which not only allows efficient drug loading but also effectively quenches the fluorescence signal of diagnostic molecules. When GO reaches the tumor tissue, the high concentration of glutathione (GSH) in the tumor environment reduces GO into reduced graphene oxide (rGO). This reduction triggers the release of fluorescent diagnostic molecules from its surface, leading to the restoration of their fluorescence signal and enabling timely tumor diagnosis. Furthermore, GO possesses strong near-infrared absorption and thermal conductivity properties. Hence, utilizing GO-based photothermal therapy, in addition to leverage its excellent photothermal conversion efficiency for direct tumor cells ablation, it achieves precise and sustained drug release based on the specific TME. Exploiting the distinctive biological properties of GO, this paper aims to provide a comprehensive overview of the latest research and related progress in the utilization of GO as a carrier for drugs and diagnostic agents in the realms of tumor diagnosis and precision treatment. First, we describe the biochemistry of GO and its application as a fluorescence quencher in tumor diagnosis. Second, capitalizing on GO's substantial surface area and environment-responsive attributes, we delve into the research progress of GO in tumor treatment. Finally, we summarize GO's biocompatibility as a drug carrier for tumor diagnosis and treatment while also discussing its future prospects.

The current work describes the algorithm for obtaining porous ammonium nitrate granules in granulation plants using devices with different fluidized bed configurations. We present brief theoretical foundations for calculating the main equipment of the granulation plant. We develop and propose the design of individual units for the sequential implementation of the main stages of ammonium nitrate modification to obtain a nanostructured porous surface layer. We assess the ammonium nitrate nanoporous structure quality and show further ways to improve the technology. Current work also pays attention to methods for ensuring the necessary specific quality indicators of porous ammonium nitrate by choosing the optimal technological mode of the unit operation and the design characteristics of the main equipment.

Respiratory infections are quite challenging due to their complexity in ailments and composition of viral genetic material and their rate of proliferation. In particular, the eradication of viral illness is still a concern, irrespective of advancements in prevention and remedial procedures. The nature of the viral particle with the possibility of rapid transmission is prone to attach on the deposited surface for days together. This antigen expulses due to sneezing or coughing resulted in multiphase turbulent flow, contaminates the surroundings and is carried away by simple touch or inhalation and find newer hosts for instance, SARSCoV-2 aerosols remain viable for about an hour leading to infection. The present review focuses on the remedial aspects of respiratory infections through a knowledge-based approach towards nanosystems. The complete understanding of standard antiviral drugs and the remodelling of these drugs through nanosystems still is the need of the hour. The genetic material and epidemiology of viral antigen, help in redefining standard drugs along with nanocarriers to achieve more feasible and hour-based approach. The main goal of this review is to elaborate on the repurposing of existing standard antiviral drugs and ways to accelerate their mode of action to promote a feasible and hour-based approach. The consolidated three-dimensional approaches aimed at sustained, targeted and optimized levels of drug concentration in the circulating system along with bioactive nanocarriers which could effectively pass the cell membrane were reported. The platforms for nanomaterial evolution depend on nature of source, size, structure, and their unique functionalities (Stable, speedy, and long-lasting recovery procedure). However, the research activities and literature on coronavirus have been overwhelming but the information on the sustainability of nanotherapy in SARS-CoV-2 is still in the developmental stage. Hereby, the clinical aspects of SARS-CoV-2 and the eradication strategy developed for antiviral infections through nanotechnology will pave the way ahead for treating upcoming new variants or other pandemics.

This study investigated the structural, morphological, and photoluminescent properties of ZnO nanopowders doped with Mo and V, which were synthesized using pulsed laser reactive technology. The nanoparticles’ structure, shape, and size were determined using electron microscopy and X-ray diffractometry. The photoluminescence properties of the Mo- and V-doped ZnO nanopowders in different gas environments were studied, revealing that changes in the gas environment led to significant alterations in the intensity and deformation of the photoluminescence spectra. All samples exhibited strong emission bands in the UV range and a broad, non-elemental emission band in the visible region ranging from 410 to 600 nm. Decomposing the photoluminescence spectra into elementary bands revealed peaks at 430 and 520 nm. Chromaticity diagrams of the photoluminescence light emitted by the nanopowders were obtained, and it was found that the color coordinates varied depending on the gas environment, which could be useful in gas sensors.

Liquefied petroleum gas (LPG) is used as fuel for cooking, heating, and transportation globally. This gas is highly inflammable, poisonous, explosive, and hazardous, and it creates several health issues when inhaled. Thus, its leakage detection is of the utmost importance. There are several sensors used for LPG detection, but they have a high operating temperature; therefore, developing sensors that work at normal temperatures has always been a challenge. This paper describes the synthesis of bismuth (Bi)-doped Praseodymium orthoferrite (PrFeO₃) nanomaterials by the sol–gel self-combustion technique and their application in LPG detection. The synthesized nanomaterials were characterized using powder X-ray diffraction (PXRD), field emission scanning electron microscope (FESEM), Brunauer–Emmett–Teller (BET), ultraviolet–visible spectroscopy (UV–Vis), and Fourier transform infrared spectroscopy (FTIR). PXRD reveals that the synthesized nanomaterial has an orthorhombic structure with the Pbnm space group, and the crystallite size (D) changes from 30 to 41 nm. FESEM was used for the analysis of surface morphology. BET analysis reveals the mesoporous nature of synthesized nanomaterials with a 16.331 to 37.645 m²g⁻¹ specific surface area. UV–Vis spectroscopy affirms the optical energy band gap lying between 2.27 and 1.95 eV. The FTIR study represents the existence of different functional groups and their lattice vibration. Synthesized nanomaterials were explored as an LPG detector working at room temperature for the first time. Different sensing parameters have been evaluated. The gas sensing studies reveal that the response and recovery times are 15.3 and 22.4 s for 0.5 vol% of LPG, and the sensor shows high selectivity towards LPG. This study reveals that the designed sensor is capable of working at room temperature, and the synthesized nanomaterials are promising for LPG sensing.

Capsule-shaped nano silver-based reduced graphene oxide nanocomposites (RGO–Ag) are prepared using “one pot” synthetic protocol. Herein, we have taken tamarind leaf extract for the reduction of Ag⁺ ion which has been used towards the synthesis of RGO–Ag nanocomposites. Different temperature conditions are considered for the optimization of formation of nanoparticles. Scanning electron microscope (SEM) has been used to find out the micrograph of as-synthesized nanocomposites. From SEM image, capsule-shaped nanocomposites can be clearly observed. The as-synthesized nanocomposites display a better response to Hg²⁺(aq) in pH 4.0–10. There is negligible effect of other ions for the recognition of Hg²⁺ (aq) ion and, therefore, as-synthesized nanocomposites can be used for the sensitive and selective recognition of mercury (II) ion in aqueous phase. Since tamarind leaf extract has been used as reducing agent and water is used as solvent, it is a green and eco-friendly process. The recognition limit of Hg²⁺ ion in water sample is found to be 15 nM.

In this study, we have investigated numerous influential factors such as length, diameter, impurity introduction, and vacancy defects on the thermal conductivity of carbon nanotubes (CNTs). These investigations were conducted through molecular dynamics simulations using the large-scale atomic/molecular massively parallel simulator (LAMMPS). It is observed that longer CNTs tend to exhibit heightened thermal conductivity, a consequence of the increased support for phonon vibration modes that facilitate efficient thermal transport. Furthermore, CNTs with larger diameters display superior thermal characteristics owing to reduced phonon scattering effects. The introduction of boron doping reduces CNTs thermal conductivity by approximately 3% with the inclusion of 6% boron atoms, whereas nitrogen doping increases it by a similar margin. These doping effects hold great potential for optimizing the performance of MEMS and NEMS devices. This duality in doping offers a versatile means to fine-tune the thermal conductivity of CNTs, enabling effective heat management in micro/nanodevices. By strategically modulating thermal conductivity, we can optimize the heat transfer properties of CNT-based materials and devices. This optimization is of utmost importance in ensuring efficient heat dissipation and averting thermal-induced issues, such as overheating, performance degradation, or failure. Additionally, this paper explores how vacancy defects impact the thermal conductivity of CNTs. By varying the vacancy concentration from 1 to 6%, a decrease in thermal conductivity of approximately 2% to 4% was observed in both SWCNTs and DWCNTs. These results emphasize the pivotal role of defects in perturbing the efficient phonon transport mechanisms in CNTs and suggest the potential for customizing CNTs with specific defect concentrations to enhance their suitability for thermoelectric devices and thermal insulation materials.

We present a straightforward method for determining the crystalline coherence length (D_c) of ZnO-based systems with long-range order in the scale of tens of nanometers. The proposed equation enables calculating D_c by simply utilizing the intensities of two peaks of a Raman measurement, namely: D_c = A (I_E1(LO)/I_E2^high) + 66.5, where I_E1(LO) and I_E2^high are the intensities of E₁(LO) and E₂^high Raman peaks, respectively, and the coefficient A depends on the laser wavelength used as excitation. Such methodology can be applied to measurements taken with most of the visible lasers available for Raman experiments. Based on the results of photoluminescence analyses, it can be inferred that the relative intensities of these Raman peaks are influenced by both D_c and the exciting laser wavelength, owing to resonance processes that selectively involve phonons out of the Brillouin Zone center. A significant competitive advantage of this method stands out in the fact that Raman spectra are very sensitive even to slight structural modifications that are below the detection limit of conventional characterization techniques, such as X-ray diffraction, and the versatile and easy way of performing in-situ analyses, in addition to the possibility to take measurements with microscopic spatial resolution without the demand for large X-ray sources or synchrotron environments.

The present study aims to improve the magnetic properties with tunable coercivity of SrM hexaferrite by substituted Co and Zn ions instead of Fe and to elucidate in detail the changes in their structural, morphological, and site occupancy characteristics. Sr({text{Co}}_x {text{Zn}}_x {text{Fe}}_{12 - 2x} {text{O}}_{19}) (Co, Zn; x = 0.4, 0.8, 1.2, 1.6 and 2.0) powders were synthesized by the autocombustion sol–gel method. Substitution of Co–Zn ions caused the formation of magnetoplumbite and a secondary phase (CoFe₂O₄) in the structure. Increasing the Co–Zn content ratio led to a nonlinear increment in crystallite size ranging from 41.9 to 49.8 nm. SEM micrographs depicted platelet-shaped hexagonal particles that were nano-scale in thickness and micro-scale in diameter. Mössbauer spectra revealed that the substituent tends to occupy both spin-up sites 12k-2a-2b and spin-down sites 4f₁ and 4f₂ of crystal lattice from x = 0.4 to x = 2.0, which elucidate meagre change observed in magnetization, as per literature. The saturation magnetization (M_s) and remanent magnetization (M_r) were higher than the initial values of M_s = 75.26 emu/g and M_r = 26.95 emu/g. The highest coercivity and saturation magnetization was observed as, 4159 Oe and 80 emu/g, respectively, for x = 2.0. The squareness ratio (M_r/M_s) of x = 1.6 and x = 2.0 samples, was observed to be greater than 0.5, elucidating the existence of single-domain particles. The magnetic parameters M_s with tunable H_c, M_r/M_s, and magnetic susceptibility (dM/dH) results make the synthesized sample considerable for recording applications.