Journal of Cluster Science最新文献

In this study, a novel Z-scheme heterojunction based on g-C₃N₄/TiO₂/NiCo₂O₄ nanocomposite was synthesized using a combination of hydrothermal and ultrasonic methods and investigated the photocatalytic degradation of Rhodamine B (RhB) dye. The synthesized nanocomposite was characterized XRD, FT-IR, FE-SEM, TEM, EDS, PL, UV–Vis DRS techniques. Subsequently, various parameters such as the effect of NiCo₂O₄ amount in the composite structure, pH, initial pollutant concentration, photocatalyst dosage, and different scavengers were investigated to determine the exact mechanism of the photocatalytic process. In different concentrations of NiCo₂O₄, the base value (X: 1) was determined as the optimal value in photocatalytic degradation. g-C₃N₄/TiO₂/NiCo₂O₄ composite had the highest percentage of 99.5% Rh.B dye degradation in 60 min. In addition, by examining the pH, it was found that its optimal value is 7, and the rate of dye degradation in this condition is more than other materials, and the rate constant value is 0.069 min^–1. In addition, the g-C₃N₄/TiO₂/NiCo₂O₄ catalyst showed good performance for each reuse and retained about 82% of its initial photocatalytic activity after 5 cycles. The results indicate that photoinducd (RhB) holes play a crucial role in the photocatalytic degradation of RhB in the presence of the g-C₃N₄/TiO₂/NiCo₂O₄ nanocomposite via pair Z-scheme system. In the Z-scheme system, the rapid recombination between the hole-electron pair is not observed due to the electron trapping effect of the needle-shaped NiCo₂O₄ structure, resulting in high photocatalytic efficiency and dye degradation. Therefore, Z-scheme systems are efficient and effective for the removal of water pollutants.

The World Health Organization (WHO) announced corona virus disease 2019 (COVID-19) caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), a serious pandemic in March 2020. The situation demands, development of rapid, convenient and easy to handle detection system for SARS-CoV-2. In this regard, the optical biosensing assay was developed using antisense oligonucleotide (ASO) conjugated Poly-l-Lysine functionalized gold nanoparticles (PLL-AuNPs) for detection of SARS-CoV-2 RNA. The negatively charged ASOs were conjugated with positively charged PLL-AuNPs by electrostatic interactions which were characterized by UV–Vis spectroscopy and Transmission Electron Microscopy (TEM). ASO-PLL-AuNPs conjugate was used to detect target SARS-CoV-2 RNA within 5–6 min from COVID-19 positive samples. In presence of target SARS-CoV-2 RNA, the DNA-RNA (ASO-RNA) hybrid structure was formed that released PLL-AuNPs which was aggregated in presence of sodium chloride (NaCl). This has rendered observable red shift in Surface Plasmon Resonance (SPR) with maximum absorbance at 660 nm and visual aggregation of PLL-AuNPs. Selectivity of ASO-PLL-AuNPs conjugate was evaluated in presence of Influenza A RNA with limit of detection 0.52 ng/µL. The obtained results were compared with qRT-PCR results for nasopharyngeal samples collected from COVID-19 positive patients and were found in good agreement with qRT-PCR results. This study reports selective and sensitive optical biosensing assay for detection of SARS-CoV-2 RNA using ASO-PLL-AuNPs conjugate without utilization of any sophisticated instruments.

Graphical Abstract

Herein, silver ions modified α-Fe₂O₃ (Ag: α-Fe₂O₃) nanoparticles were synthesized using a sol-gel auto-combustion method comprising of dual phase i.e. trigonal structure of α-Fe₂O₃ and FCC structure of Ag. The refinement results verified the existence of both the phase with R-3c: R s and Fm-3 m space group. Transmission Electron Microscopy (TEM) showed the crystallite size around 34.24 ± 2.00 nm. The percentage of Ag⁰ and Ag⁺ verified through X-ray Photoelectron Spectroscopy (XPS) clearly indicate that around 74% of the Ag present is in the metallic form. The cyclic voltammetry showed that the C_sp of the Ag: α-Fe₂O₃ NPs modified electrode is 132 Fg ^− 1 and 100 Fg ^− 1 when recorded at a scan rate of 50 mVs^− 1 and 75 mVs^− 1, respectively. The Zones of Inhibition (ZOI) against bacterial strains generated by utilizing Ag: α-Fe₂O₃ NPs are clearly showed the ZOI of 19 ± 1 mm against Bacillus subtilis. The synthesized nanoparticles exhibited higher inhibition against the bacterial strains in comparison to the standard antibiotic ampicillin. Further, cell viability analysis suggested to use a concentration of 9 to 12 µg/ml for Ag: α-Fe₂O₃in invitro experiments.

Chronic inflammation underpins many severe diseases, often requiring anti-inflammatory drugs that can have adverse effects. Medicinal herbs offer an alternative but suffer from poor solubility, limiting their efficacy. Nanotechnology, particularly zinc oxide nanoparticles (ZnO NPs), presents a promising solution to enhance the therapeutic potential of herbal compounds. This review examines the nature and benefits of ZnO NPs in drug delivery systems compared to other nanomaterials. It highlights the advantages of biogenic synthesis of ZnO NPs, detailing the eco-friendly formation mechanisms and common characterization methods. The anti-inflammatory effects of biosynthesized ZnO NPs over the last five years are comprehensively reviewed, with insights into their mechanisms of action. Additionally, the pharmacokinetic and toxicokinetic profiles of ZnO NPs are explored to understand their biokinetics post-drug release. In conclusion, biogenically synthesized ZnO NPs enhance the bioavailability of medicinal plant compounds, offering a compelling alternative for treating inflammatory conditions.

In industrial production, the preparation of cubic boron nitride (cBN) under high temperature and pressure wastes a large amount of unreacted hexagonal boron nitride (hBN). This study aims to use this BN waste (wBN) as a raw material, composite it with g-C₃N₄ to construct wBN/g-C₃N₄ composites, and apply the composites in the field of photocatalysis. wBN/g-C₃N₄ composites were prepared by simple calcination using wBN and ammonium cyanide as raw materials. Results showed that a heterogeneous structure was formed in the composite photocatalyst, with a decrease in its bandgap width and a significant increase in its ability to absorb light. The simulated sunlight photocatalytic activity of composite photocatalysts was significantly better than that of single wBN or g-C₃N₄. The photocatalytic performance of B2 sample, composed of a 4:3 ratio of wBN and melamine in the raw materials, demonstrated the highest efficiency. Under simulated solar illumination, it was capable of degrading 99.3% of MB within 60 min. The experimental results with additional capture agents indicated that the main reactive species of the composite photocatalyst were superoxide radicals (·O₂⁻) and holes (h⁺).

Environmental pollution by toxic heavy metals is increasing at an alarming rate which demands the development of an appropriate analytical method to investigate and quantify the target analytes. In response to this call, polyaniline Titanium (IV) tungstomolybdate (PANI/TWM) nanocomposite was synthesized by incorporating polyaniline into Titanium (IV) tungstomolybdate using sol–gel method. The material was then characterized using X-ray diffraction (XRD), UV-Vis, Fourier transform infrared (FTIR), Thermogravimetric analysis (TGA-DTA), and Scanning electron microscope (SEM-EDX). It was amorphous with appreciable thermal stability as it retained 65.2% of its ion exchange capacity (IEC) up to 600 ^OC. It acts as a bifunctional strong acid cation exchanger with an IEC of 1.58 meq/g for Na⁺ ions. Moreover, the high distribution coefficients (Kd) of 1572 and 928 mL/g for Pb(II) and Co(II), respectively, indicate its potential to treat these ions in an aqueous matrix selectively. Real sample treatment with the prepared material was undertaken for binary separation of selected metal ions in column mode and practically appreciable efficiency (90.3 to 96.8%) was achieved. Therefore, the synthesized material can be considered as a promising cation exchanger to treat an environmental matrix containing toxic heavy metals.

Non-steroidal anti-inflammatory drugs (NSAIDs) have received attention to be used in combination with antibiotics in antibacterial chemotherapy. However, this study is the first to explore the impact of dual encapsulation of diclofenac sodium and gentamicin within PLGA nanoparticles (DS-GEN-PLGA NPs) on inhibiting extracellular matrix components and biofilm eradication of Pseudomonas aeruginosa PAO1. DS-GEN-PLGA NPs were prepared using the double emulsion solvent evaporation (DESE) technique and characterized by various characterization techniques. Subsequently, the inhibition and eradication potential of DS-GEN-PLGA NPs against P. aeruginosa biofilm was explored. The DS-GEN-PLGA NPs are spherical and oval and 80–200 nm in diameter. DS-GEN-PLGA NPs significantly reduced biofilm formation by 76.28%, biofilm metabolic level by 69.8%, biofilm exopolysaccharide by 75.3%, alginate production by 32.56%, and eDNA release by 60.2%. The expression level of the lasI and rhlI decreased by 0.29 and 0.44 folds compared with untreated cells. This study indicates that DS-GEN-PLGA NPs have promising antibiofilm activity against P. aeruginosa, highlighting its potential as a novel therapeutic formulation to combat biofilm-related infections.