Zirconium nanoparticles prepared by the reduction of zirconium oxide using the RAPET method

One-Pot Synthesis of Silver/Zirconium Nanoparticles Using Sargassum tenerrimum for the Evaluation of Their Antibacterial and Antioxidant Activities

INTRODUCTION

The global health threat posed by worldwide antimicrobial resistance necessitated immediate multisectoral action by the scientific community to achieve sustainable development goals. Silver and zirconium nanoparticles (Ag/ZrO-NPs), known for their antimicrobial properties, have the potential to combat pathogens effectively, making them versatile for various applications across different fields.

OBJECTIVE

 This study aims to synthesize and characterize Sargassum tenerimum-mediated Ag/ZrO-NPs and evaluate their antioxidant and antibacterial efficacy against multidrug resistant (MDR) pathogens.

METHODOLOGY

The synthesis of Ag/ZrO-NPs using the one-pot green synthesis method was conducted and followed by using characterization techniques, namely, UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), and energy-dispersive X-ray analysis (EDX). The antibacterial activity was assessed using the agar well diffusion method, and antioxidant activity was determined using the DPPH(2,2-diphenyl-1-picrylhydrazyl) method. Statistical analysis was analyzed using the IBM SPSS Statistics for Windows, version 21.0 (released 2012, IBM Corp., Armonk, NY).

RESULTS

The green-synthesized Ag/ZrO-NPs exhibited a color change from dark brown to creamy white, indicating the successful reduction of the nanoparticles. UV-analysis peaks were observed at 310-330 nm, while the FT-IR analysis showed the peaks at various wavelengths, such as 648.9 cm-1 (alkyne C-H bond), 1041.14 cm-1 (aliphatic fluoro compounds, C-F stretch), 1382.54 cm-1 (dimethyl -CH3), 1589.6 cm-1 (primary amine, N-H bond), and 3353.8 cm-1 (aliphatic secondary amine, N-H stretch). The crystallinity of the nanoparticles was determined to be 59.5%, while the remaining 40.5% exhibited an amorphous structure. The SEM image revealed the spherically agglomerated structure of the nano-ranged size Ag/ZrO-NPs. The EDX analysis indicated the presence of elemental compositions Zr (16.2%), Ag (18.8%), and C (28.7%) in the green-synthesized Ag/ZrO-NPs. These nanoparticles demonstrated significant antibacterial activity against Pseudomonas aeruginosa, Enterococcus faecalis, and Methicillin-resistant Staphylococcus aureus (MRSA). The moderate antibacterial activity against E. coli showed thesignificant antioxidant activity in a dose-dependent manner.

CONCLUSION

The green-synthesized Ag/ZrO-NPs showed notable antibacterial and antioxidant activity. In future aspects, it may be used as a potential drug after completion of in-vivo and in-vitro studies.

Microwave engineered NiZrO3@GNP as efficient electrode material for energy storage applications

Supercapacitors (SCs) have emerged as attractive energy storage devices due to their rapid charge/discharge rates, long cycle life, and high-power density. However, the development of innovative electrode materials to achieve high-performance remains crucial to meet future requirements in supercapacitor technology. In this work, we have explored the potential of a microwave-engineered NiZrO3@GNP composite as a promising electrode material for SCs. A microwave assisted hydrothermal approach was adopted for the fabrication of the NiZrO3@GNP nanocomposite. Structural and morphological investigations showed its structural richness and its chemical compositions. When applied as a SC electrode, this innovative combination exhibits battery-like behaviour with higher specific capacity (577.63 C g-1) with good cyclic stability, and good performance. We have assembled an asymmetric-type two-electrode SC device and analysed its electrochemical features. This NiZrO3@GNP device exhibits the specific capacity of 47 C g-1 with capacitance retention of 70% after 2000 charge-discharge cycles. Further research on optimizing the synthesis process and exploring different device configurations could pave the way for even higher-performance supercapacitors in the future.

A piperazine- modified Schiff base sensor for highly selective detection of Zr (IV) ions: unveiling its antioxidant potential and regulatory effects on Zea mays growth

Piperazine functionalized Schiff bases 4(a-c) were synthesized by a condensation reaction which were thoroughly characterized by using various spectroscopic techniques like 1H NMR, 13C NMR, IR and mass spectrometry. X-ray crystallography was used to analyse synthesized compound 4b. The sensing capability of 4b was investigated towards the tetravalent form of the zirconium ion among other metal ions. The limit of detection and the association constant, were calculated to be 56.4 × 10-8 M and 5.36 × 105 M-1 respectively. The inclusion of additional metal ions had no effect on the selectivity of sensor 4b. The binding mechanism was clarified using 1HNMR spectroscopy, which was further verified computationally, using DFT. Also, the seed germination experiments were performed and effect of compound 4b was analyzed on the seedlings of Zea Mays. An investigation into molecular docking study using (5HQX) protein revealed that it had inhibitory effects on cytokinin oxidase. The protein and ligand effectively associate, as indicated by the lower binding energy of -9.69 kcal/mol. Therefore, compound 4b can act as a good, powerful inhibitor against cytokinin oxidase.

Use of manganese oxide nanoparticle (MnO2 NPs) and Pseudomonas putida for the management of wilt disease complex of carrot

Wilt disease complex of carrot is caused by Ralstonia solancearum and Meloidogyne incognita and is responsible for considerable yield loss. Manganese oxide nanoparticle (MnO2 NPs) and Pseudomonas putida were used alone and in combination for the management of wilt disease complex. In vitro, MnO2 NPs 0.10 g.L-l caused 49.36% reduction in hatching and 14.23% mortality of second stage juveniles (J2) of M. incognita while paper disc dipped in MnO2 NPs suspension caused 0.51 mm inhibition zone around R. solanacearum in nutrient agar medium. Inoculation of P. putida to plants with pathogens caused a similar increase in plant growth, chlorophyll and carotenoid contents as caused by foliar spray with 0.10 g.L-1 MnO2 NPs. Use of P. putida with NPs foliar spray to plants with pathogens caused a greater increase in plant growth, chlorophyll and carotenoid contents than with P. putida or NPs foliar spray. Inoculation of M. incognita/R. solanacearum/M. incognita plus R. solanacearum/P. putida/MnO2 NPs and MnO2 NPs plus P. putida caused increase in proline contents. Root colonization by P. putida was reduced in plants with test pathogens. Foliar application of MnO2 NPs and P. putida reduce wilt disease indices. Galling and populations of M. incognita was also reduced in plants co-inoculated with R. solanacearum. The greatest reduction in nematode populations and galling was observed in plants with NPs spray together with P. putida. Principal component analysis demonstrated a clear influence of NPS and P. putida and their combination on various studied parameters in diseased plants.

Sc, Zr, Hf, and Mn Metal Nanoparticles: Reactive Starting Materials for Synthesis Near Room Temperature

Zerovalent scandium, zirconium, hafnium, and manganese nanoparticles are prepared by reduction of ScCl3, ZrCl4, HfCl4, and MnCl2 with lithium or sodium naphthalenide in a one-pot, liquid-phase synthesis. Small-sized monocrystalline nanoparticles are obtained with diameters of 2.4 ± 0.2 nm (Sc), 4.0 ± 0.9 nm (Zr), 8.0 ± 3.9 nm (Hf) and 2.4 ± 0.3 nm (Mn). Thereof, Zr(0) and Hf(0) nanoparticles with such size are shown for the first time. To probe the reactivity and reactions of the as-prepared Sc(0), Zr(0), Hf(0), and Mn(0) nanoparticles, they are exemplarily reacted in the liquid phase (e.g., THF, toluene, ionic liquids) with different sterically demanding, monodentate to multidentate ligands, mainly comprising O-H and N-H acidic alcohols and amines. These include isopropanol (HOiPr), 1,1'-bi-2-naphthol (H2binol), N,N'-bis(salicylidene)ethylenediamine (H2salen), 2-mercaptopyridine (2-Hmpy), 2,6-diisopropylaniline (H2dipa), carbazole (Hcz), triphenylphosphane (PPh3), N,N,N',N'-tetramethylethylenediamine (tmeda), 2,2'-bipyridine (bipy), N,N'-diphenylformamidine (Hdpfa), N,N'-(2,6-diisopropylphenyl)-2,4-pentanediimine ((dipp)2nacnacH), 2,2'-dipydridylamine (Hdpa), and 2,6-bis(2-benzimidazolyl)pyridine (H2bbp). As a result, 22 new compounds are obtained, which frequently exhibit a metal center coordinated only by the sterically demanding ligand. Options and restrictions for the liquid-phase syntheses of novel coordination compounds using the oxidation of base-metal nanoparticles near room temperature are evaluated.

A Comparative Study on Bio-Based PU Foam Reinforced with Nanoparticles for EMI-Shielding Applications

Today, most commercial polyols used to make polyurethane (PU) foam are produced from petrochemicals. A renewable resource, castor oil (CO), was employed in this study to alleviate concerns about environmental contamination. This study intends to fabricate a bio-based and low-density EMI-defending material for communication, aerospace, electronics, and military appliances. The mechanical stirrer produces the flexible bio-based polyurethane foam and combines it with nanoparticles using absorption and hydrothermal reduction processes. The nanoparticles used in this research are graphite nanoplates (GNP), zirconium oxide (ZrO₂), and bamboo charcoal (BC). Following fabrication, the samples underwent EMI testing using an EMI test setup with model number N5230A PNA-L. The EMI experimental results were compared with computational simulation using COMSOL Multiphysics 5.4 and an optimization tool using response surface methodology. A statistical design of the experimental approach is used to design and evaluate the experiments systematically. An experimental study reveals that a 0.3 weight percentage of GNP, a 0.3 weight percentage of ZrO₂, and a 2.5 weight percentage of BC depict a maximum EMI SE of 28.03 dB in the 8–12 GHz frequency band.

Enhanced Thermal Properties of Zirconia Nanoparticles and Chitosan-Based Intumescent Flame Retardant Coatings

Zirconia (ZrO2)-based flame retardant coatings were synthesized through the process of grinding, mixing, and curing. The flame retardant coatings reinforced with zirconia nanoparticles (ZrO2 NPs) were prepared at four different formulation levels marked by F0 (without adding ZrO2 NPs), F1 (1% w/w ZrO2 NPs), F2 (2% w/w ZrO2 NPs), and F3 (3% w/w ZrO2 NPs) in combination with epoxy resin, ammonium polyphosphate, boric acid, chitosan, and melamine. The prepared formulated coatings were characterized by flammability tests, combustion tests, and thermogravimetric analysis. Finally, char residues were examined with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The peak heat release rate (PHRR) of the controlled sample filled with functionalized ZrO2 NPs was observed to decrease dramatically with increasing functionalized ZrO2 NPs loadings. There was an increase in the limit of oxygen index (LOI) value with the increase in the weight percentage of ZrO2 NPs. The UL-94V data clearly revealed a V-1 rating for the F0 sample; however, with the addition of ZrO2 NPs, the samples showed enhanced properties with a V-0 rating. Thermal gravimetric analysis (TGA) results revealed that addition of ZrO2 NPs Improved composite coating thermal stability at 800 °C by forming high residual char. The results obtained here reveal that the addition of ZrO2 NPs in the formulated coatings has shown the excellent impact as flame retardant coatings.

Chiral zirconium quantum dots: A new class of nanocrystals for optical detection of coronavirus

A synthetic way of chiral zirconium quantum dots (Zr QDs) was presented for the first time using L(+)-ascorbic acid acts as a surface as well as chiral ligands. Different spectroscopic and microscopic analysis was performed for thorough characterization of Zr QDs. As-synthesized QDs exhibited fluorescence and circular dichroism properties, and the peaks were located at 412 nm and 352 nm, respectively. MTT assay was performed to test the cytotoxicity of the synthesized Zr QDs against rat brain glioma C6 cells. Synthesized QDs was further conjugated with anti-infectious bronchitis virus (IBV) antibodies of coronavirus to form an immunolink at the presence of the target analyte and anti-IBV antibody-conjugated magneto-plasmonic nanoparticles (MPNPs). The fluorescence properties of immuno-conjugated QD–MP NPs nanohybrids through separation by an external magnetic field enabled biosensing of coronavirus with a limit of detection of 79.15 EID/50 μL.

Synthesis and characterization of Zr- and Hf-doped nano-TiO2 as internal standards for analytical quantification of nanomaterials in complex matrices

The reliable quantification of nanomaterials (NMs) in complex matrices such as food, cosmetics and biological and environmental compartments can be challenging due to interactions with matrix components and analytical equipment (vials and tubing). The resulting losses along the analytical process (sampling, extraction, clean-up, separation and detection) hamper the quantification of the target NMs in these matrices as well as the compatibility of results and meaningful interpretations in safety assessments. These issues can be overcome by the addition of known amounts of internal/recovery standards to the sample prior to analysis. These standards need to replicate the behaviour of target analytes in the analytical process, which is mainly defined by the surface properties. Moreover, they need to carry a tag that can be quantified independently of the target analyte. As inductively coupled plasma mass spectrometry is used for the identification and quantification of NMs, doping with isotopes, target analytes or with chemically related rare elements is a promising approach. We present the synthesis of a library of TiO2 NMs doped with hafnium (Hf) and zirconium (Zr) (both low in environmental abundance). Zirconia NMs doped with Hf were also synthesized to complement the library. NMs were synthesized with morphological and size properties similar to commercially available TiO2. Characterization included: transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy, X-ray diffraction spectroscopy, Brunauer-Emmett-Teller total specific surface area analysis, cryofixation scanning electron microscopy, inductively coupled plasma optical emission spectroscopy and UV-visible spectrometry. The Ti : Hf and Ti : Zr ratios were verified and calculated using Rietveld refinement. The labelled NMs can serve as internal standards to track the extraction efficiency from complex matrices, and increase method robustness and traceability of characterization/quantification.

Photocatalytic activity against azo dye and cytotoxicity on MCF-7 cell lines of zirconium oxide nanoparticle mediated using leaves of Lagerstroemia speciosa

Metal oxide nanoparticles are gaining interest in recent years. The present paper explains about the green synthesis of zirconium oxide nanoparticles (ZrO NPs) mediated from the leaves of Lagerstroemia speciosa. The prepared ZrO NPs were characterized by UV-vis spectroscopy, FT-IR, X-ray diffraction analysis (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Thermogravimetric Analysis (TGA). The photocatalytic activity of ZrO NPs was studied for azo dye by exposing to sunlight. The azo dye was degraded up to 94.58%. Also the ZrO NPs were studied for in vitro cytotoxicity activity against breast cancer cell lines-MCF-7 and evaluated by MTT assay. The cell morphological changes were recorded by light microscope. The cells viability was seen at 500μg/mL when compared against control. Hence the research highlights, that the method was simple, eco-friendly towards environment by phytoremediation activity of the azo dye and cytotoxicity activity against MCF-7 cell lines. Hence the present paper may help to further explore the metal nanoparticle for its potential applications.

Methods and strategies for the synthesis of diverse nanoparticles and their applications: a comprehensive overview

Various methods to synthesize diverse nanoparticles with their different applications.