These days, research in agriculture is focusing on the theme of sustainability along with protection of agriculture produce. Nanotechnology in the agriculture sector aims for the enhancement of ...agricultural produce and the reduction of pesticides through providing innovative agrochemical agents and their novel delivery mechanisms. The current investigation involved the green synthesis of silver nanoparticles (AgNPs) from the aqueous leaf extract of
by following a microwave-assisted method to control
, the causal agent of tomato wilt. Biosynthesized
leaf extract (MLE)-AgNPs were characterized by UV-visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectrometry, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and zeta potential analysis. The intensity of the peak at 434 nm in UV-vis spectra, attributed to the surface plasmon resonance of MLE-AgNPs, changes with reaction parameters. TEM exhibits spherical shaped nanoparticles with an average particle size range from 12 to 46 nm. Efficient inhibition of
, the causal agent of tomato wilt, was achieved after exposure to MLE-AgNPs both
and
.
studies exhibited repressed fungal mycelial growth with 79-98% inhibition as compared to the control. Significant increases in growth parameters of tomato seedlings were observed after treatment with biosynthesized nanoparticles as compared to
-infected plants grown without them under greenhouse conditions. Furthermore, SEM imaging was done to reveal the prominent damage on the cell wall of hyphae and spores after MLE-AgNP treatment. Propidium iodide (PI) staining of mycelium indicated the extent of cell death, causing irretrievable damage and disintegration of cellular membranes by altering the membrane permeability. Also, 2',7'-dichlorofluorescin diacetate (DCFH-DA) fluorescence specifies intracellular reactive oxygen species (ROS) production in
after treatment with MLE-AgNPs. The current investigation suggested that biosynthesized nanoparticles can revolutionize the field of plant pathology by introducing an environment-friendly approach for disease management and playing a potential part in agriculture industry. However, to date, little work has been done to integrate nanotechnology into phytopathology so, this area of research is in need of adoption and exploration for the management of plant diseases.
The properties of manganese-doped ZnO nano-particles fabricated by the sol-gel method were studied. The concentration of Mn in the ZnO was 1–4% w/w. The X-ray diffraction (XRD) confirmed wurtzite ...phase of ZnO. The results showed that Mn
2+
ions substituted Zn
2+
ions without altering the wurtzite structure of ZnO. Crystallite size was increased with increase in Mn doping percentage. Optical transmission recorded by UV–VIS–NIR spectrophotometer decreased with increase in Mn doping percentage. The optical band gap energy was quite low in the range 2.99–3.18 eV as compared to undoped ZnO and found to change with the increase in Mn percentage. Magnetic study displays that the Mn doped ZnO nanoparticles show ferro-magnetism at room temperature and the variation of the Mn percentage can tailor the ferromagnetic behavior of the nano-particles. Maximum coercivity of 228.07(Oe) is achieved for 2.5% Mn dopant and saturation magnetization is 0.03780 emu/g for 1.5% of Mn. Photo-catalytic activity was explored against methylene blue. 1% Mn contents have shown better photo-catalytic activity. It was discovered that ZnO nanoparticles with Mn doping displayed good antibacterial efficiency against
Escherichia coli
(
E. coli
) and
Pseudomonas aeruginosa
(
P. aeruginosa
) bacteria. The results displayed that the antibacterial activity of Mn doped ZnO nano-particles enhances with an increase in Mn percentage. Surface morphology is modified with an increase in Mn percentage. All thin films consist of nano-sized dispersed particles which are in agreement with the XRD results.
Silver nanoparticles (AgNPs) of different shapes and sizes were prepared by solution-based chemical reduction routes. Silver nitrate was used as a precursor, tri-sodium citrate (TSC) and sodium ...borohydride as reducing agents, while polyvinylpyrrolidone (PVP) was used as a stabilizing agent. The morphology, size, and structural properties of obtained nanoparticles were characterized by scanning electron microscopy (SEM), UV-visible spectroscopy (UV-VIS), and X-ray diffraction (XRD) techniques. Spherical AgNPs, as depicted by SEM, were found to have diameters in the range of 15 to 90 nm while lengths of the edges of the triangular particles were about 150 nm. The characteristic surface plasmon resonance (SPR) peaks of different spherical silver colloids occurring in the wavelength range of 397 to 504 nm, whereas triangular particles showed two peaks, first at 392 nm and second at 789 nm as measured by UV-VIS. The XRD spectra of the prepared samples indicated the face-centered cubic crystalline structure of metallic AgNPs. The
antibacterial properties of all synthesized AgNPs against two types of Gram-negative bacteria,
and
were examined by Kirby-Bauer disk diffusion susceptibility method. It was noticed that the smallest-sized spherical AgNPs demonstrated a better antibacterial activity against both bacterial strains as compared to the triangular and larger spherical shaped AgNPs.
Enteric bacterial human pathogens,
, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Klebsiella pneumoniae, are the major cause of diarrheal infections in children and adults. Their ...structure badly affects the human immune system. It is important to explore new antibacterial agents instead of antibiotics for treatment. This project is an attempt to explain how gold nanoparticles affect these bacteria. We investigated the important role of the mean particle size, and the inhibition of a bacterium is dose-dependent. Ultra Violet (UV)-visible spectroscopy revealed the size of chemically synthesized gold nanoparticle as 6-40 nm. Atomic force microscopy (AFM) analysis confirmed the size and X-ray diffractometry (XRD) analysis determined the polycrystalline nature of gold nanoparticles. The present findings explained how gold nanoparticles lyse Gram-negative and Gram-positive bacteria.
Sol–gel-based phenolphthalein immobilized AuNPs (phph-AuNPs) of different shapes such as spherical, dendrites, and flower are observed by varying pHs 1–12. pH 1 induced the Au cages, and pH 2–6 ...revealed the different shapes of dendrites. Moreover, pH 7–8 assisted phph-AuNPs exhibited the spherical shape which transformed into truncated dendrites such as flowers at pH 9–11, and again spheres at pH 12. FTIR spectra exhibited the bonding vibration of AuNPs and phenols. pH 12 assisted phph-AuNPs are observed highly porous (79%) compared to pH 1 assisted phph-AuNPs (60%) porosity and low (1.1) refractive index. Furthermore, pH 1 assisted phph-AuNPs are found to possess RMS 11 nm and thickness 56 nm which increased up to 23 and 88 nm, respectively, by increasing the pH up to 12. The pKa ~9.4 of the pH 1–12 assisted phph dye is observed at 559 nm which increased up to 9.9 at 556 nm for pH 1–12 assisted phph-AuNPs, suggesting a wide range of sensitivity. Fast response time ~0.6 s is measured at pH 12 assisted phph-AuNPs. At acidic pH, higher photoluminescence (PL) intensity indicates a high charge carrier’s recombination. Experimental findings confirmed that pH has a great influence on the morphology of phph-AuNPs.
Highlights
Sol–gel based phph-AuNPs of different shapes such as spherical, dendrites, and flower is observed by varying the pHs 1–12.
FTIR spectra exhibited the bonding vibration of AuNPs and phenols.
pH 12 assisted phph-AuNPs are observed to be highly porous 79%.
The pKa ~9.9 at 559 nm of the pH 1–12 assisted phph-AuNPs, suggested a wide range of sensitivity.
Response time ~0.6 s is measured at pH 12 assisted phph-AuNPs.
B-doped ZnO thin films have been synthesized by a sol–gel dip-coating deposition technique. Deposition conditions were optimized to achieve highly ordered thin films. XRD patterns confirm that B ions ...are inserted into the ZnO; lattice and the crystallite size decrease from 25.83 to 20.94 nm as the amount of B increases to optimal value (9 at.wt%). Synthesized B-doped ZnO thin films have ordered hexagonal wurtzite structures and granular morphology with high specific surface area. Optical transmittance spectra display transparency in the visible region. The band gap of the films decreases from 3.89 to 3.04 eV with the increase in B concentration. Band gap lowering is due to increase of defect level with the increase in B dopant percentage. The origin of the ferromagnetism is explained in terms of oxygen vacancies and Zn interstitials. Dielectric constant increases while DC conductivity and AC conductivity decrease with the increase in B doping. Antibacterial activity increases with the increase in B doping percentage but lower than undoped ZnO due to large crystallite size of B-doped ZnO nanostructures.
Composites play important role in dental filling by controlling shrinkage along with correction in teeth's shape and position. Rehabilitation of severely worn dentition can be achieved using ...mechanically strong composites. This study aims to synthesize zirconia-based composites to be used as dental fillers. Effect of microwave powers (100–900 W) along with Fe3O4 doping are studied on the structural, mechanical and magnetic properties of stabilized zirconia. SEM and TEM reveal formation of spherical nanoparticles with diameter of ∼30 nm. XRD results shows phase pure tetragonal zirconia (t-ZrO2) at microwave power of 500 W without any post heat treatment. Crystallite size calculated from XRD data (∼23 nm) matches well with the previously reported value for stabilization of t-ZrO2. Microwave energy dissipation results in stresses causing volume shrinkage leading to monoclinic to tetragonal phase transformation with higher X-ray density and hardness of ∼1347HV. VSM results show ferromagnetic response with low coercivity (600Oe) value and saturation magnetization (∼2emu/g). It is worth mentioning here that this is one of its kind study reporting synthesis of room temperature stabilized Fe3O4 doped zirconia composites at microwave power of 500 W. Antibacterial studies reveal inhibition zone of ∼32 mm against bacillus bacteria suggesting their potential use as dental filler.
The current study emphasizes the synthesis of iron oxide nanoparticles (IONPs) and impact of hydrophilic polymer polyvinyl alcohol (PVA) coating concentration as well as anticancer drug doxorubicin ...(DOX) loading on saturation magnetization for target drug delivery applications. Iron oxide nanoparticles particles were synthesized by a reformed version of the co-precipitation method. The coating of polyvinyl alcohol along with doxorubicin loading was carried out by the physical immobilization method. X-ray diffraction confirmed the magnetite (Fe3O4) structure of particles that remained unchanged before and after polyvinyl alcohol coating and drug loading. Microstructure and morphological analysis was carried out by transmission electron microscopy revealing the formation of nanoparticles with an average size of 10 nm with slight variation after coating and drug loading. Transmission electron microscopy, energy dispersive, and Fourier transform infrared spectra further confirmed the conjugation of polymer and doxorubicin with iron oxide nanoparticles. The room temperature superparamagnetic behavior of polymer-coated and drug-loaded magnetite nanoparticles were studied by vibrating sample magnetometer. The variation in saturation magnetization after coating evaluated that a sufficient amount of polyvinyl alcohol would be 3 wt. % regarding the externally controlled movement of IONPs in blood under the influence of applied magnetic field for in-vivo target drug delivery.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ag-doped ZnO thin films are prepared by the cost-effective sol–gel dip-coating method at room temperature. The Ag dopant percentage varies between (2–10) wt%. The magnetic and dielectric properties ...have been studied. The dielectric and magnetic properties of ZnO are significantly tailored by the increase in the Ag doping percentage. High dielectric constant and tangent loss have been observed at low frequencies which decreases with the increase in frequency. The AC conductivity is lower in the low-frequency region but has larger values in the high-frequency region. The ferromagnetic behavior of films has been recorded at room temperature. Magnetic polarons play a pivotal role in the development of room temperature ferromagnetism in Ag-doped ZnO thin films. So, ferromagnetism in thin films is governed by bound magnetic polarons. As the doping concentration increased, the saturation magnetization decreased and coercivity increased due to the combined effect of the decrease in crystallite size, generation of large defects, and formation of bound magnetic polarons. These Ag-doped ZnO thin films are suitable for spintronics.
Cancer treatment remains a pressing global challenge, with magnetic hyperthermia emerging as a promising alternative approach. The article explores the potential of pure and doped magnetite ...nanoparticles for hyperthermia-based cancer treatment, aiming to enhance therapeutic efficacy while minimizing side effects. Key findings include the synthesis and characterization of NPs—Fe
3
O
4
, SnFe
2
O
4
, and CoFe
2
O
4
—using co-precipitation methods, with emphasis on their size, morphology, magnetic, structural and thermal properties confirmed through techniques like SEM, EDX, VSM, XRD and TGA. The nanoparticles' hyperthermic effects were assessed through infrared imaging, showing CoFe
2
O
4
NPs induced the highest heating efficiency as compared to Fe
3
O
4
and SnFe
2
O
4
NPs. Importantly, all nanoparticles showed negligible hemolysis at a concentration of 0.2 mg/ml, indicating their compatibility with human blood. This study contributes valuable insights into optimizing MNP-based hyperthermia treatments, aiming for safer and more effective cancer therapies in the future. SnFe
2
O
4
NPs haven't been extensively explored in the context of hyperthermia applications, making it a unique contribution to the field. The research employs an innovative and cost-effective method for evaluating the hyperthermic effect of nanoparticles using an infrared camera. This approach overcomes the potential limitations associated with probe-based temperature measurement, offering a more accurate assessment of nanoparticle-induced hyperthermia. The research thoroughly compares its findings with existing literature, highlighting the novelty of the achieved results in terms of maximum hyperthermia with minimal frequency and magnetic field strength without inducing toxicity in human blood.
PDF
