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Controlling foodborne pathogens is challenging due to the new emergence of antimicrobial resistance to conventional antimicrobials. Therefore, new alternative antimicrobials need to be developed to control foodborne pathogens and avoid microbial resistance. Furthermore, the potential of trans-Himalayan high-altitude seabuckthorn (Hippophae rhamnoides ) plants has not been explored much for the synthesis of silver nanoparticles having antibacterial properties. Hence, this study investigated the development of long-term stable silver nanomaterials using the aqueous extract of seabuckthorn leaves through a green-synthesis approach and evaluated their antibacterial efficacy. These synthesized nanomaterials were characterized along with their stability using UV spectrometry for lambda max ($\lambda max$) characteristics. Further, the nanoparticles were evaluated for zeta potential (mV), polydispersity index, particle size distribution (nm), electrophoretic mobility ($\mu$mcm/Vs) and conductivity (mS/cm). The seabuckthorn silver nanoparticles are of 260$$nm size and stable (−15$$mV zeta potential) with good antioxidant and antibacterial properties against two typical food pathogens, e.g., Escherichia coli (MTCC 3222) and Salmonella typhimurium (MTCC 3224). Hence, this study developed an eco-friendly, rapid, low-cost green synthesis method for the development of seabuckthorn-coated, stable silver nanoparticles with good antibacterial activity against foodborne pathogens.

This research work describes the cost-effective synthesis and purification of multiwall carbon nanotubes (MWCNTs). Synthesis of CNTs was carried out in distilled water between two electrodes using the electric arc discharge (EAD) method. EAD is a simple and straightforward route in which an electric arc is generated between graphite electrodes through DC power source to produce soot which contains MWCNTs along with impurities. The deposited soot containing MWCNTs was then chipped off and purified. In this case, multistep purification scheme was opted to remove unwanted impurities from produced MWCNTs. Purification route comprised thermal treatment, chemical treatment and a combination of both to yield pure MWCNTs. Thermal treatments were carried out in normal air and under controlled flow of oxygen at different temperatures whereas chemical treatment was performed using acidic solution. Thermo gravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) were carried out before and after purification treatments to investigate the outcome of employed treatments. Results showed that the thermal or chemical treatment alone is not sufficient to remove impurities from soot. Moreover, the introduction of an oxide group through chemical treatment reduces the oxidization temperature of graphitic particles. It was found that the chemical treatment followed by thermal annealing under the controlled flow of oxygen is the most appropriate method for successful purification of MWCNTs synthesized via EAD method.

Dye-Sensitized Solar Cells (DSSC) and optical fiber-based-sensors sensitized with organic dyes play a fundamental role in modern technology, particularly in the family of photovoltaic power generation devices and measurement of chemical variables. DSSC is low-cost, highly efficient, and easy to manufacture. Therefore, they are a suitable option for many engineering applications. This paper deals with natural pigment extraction (spirulina, carrots (beta-carotene), and beetroot) at different milling and temperature conditions. Nanoparticles were fabricated using an SPEX mill and a planetary ball mill. The particle size distribution, absorbance (UV-Vis), and powder morphology were obtained using Field Emission Scanning Electron Microscopy (FESEM). Herein, the optical characterization of modified TiO₂ powder at different temperatures and milling conditions is performed. Results indicate that each natural dye is sensitive to operational temperature. In addition, the absorbance of the pigments is affected by milling conditions and particle size distribution. During SEM characterization, rounded particles were observed in the starting materials with average sizes of more than 15 microns in diameter until they were reduced to nanometer ranges close to 100 using SPEX milling. The observed absorption spectra range from 400 nm to 642 nm for spirulina. Moreover, the experimental results show that the intensity of the absorption peaks is affected by the temperature, which indicates a degradation of the dye. Therefore, different combinations of natural dyes will be feasible to improve the wide range of light absorption of the visible spectra and stability of DSSCs and optical fiber-based sensors.

Tumor microenvironment severely restricts the delivery of chemotherapy drugs. The microenvironment responsive nanoparticles often have complex designs with hampered clinical translatability. Here, we show a kind of ionic liquids (ILs) with soybean lecithin (SL) as cation, folic acid (FA) as anion, in particular, it could formulate nanoliposome by film evaporation method to deliver cis-Diamineplatinum (II) dichloride (cisplatin, Cis) and doxorubicin hydrochloride (DOX). These special ILs liposome could target tumor cells via folate receptor-mediated endocytosis by enhancing the cellular uptake, and significantly improve the deep permeability by actively infiltrating throughout the tumor tissue owing to the special noncovalent bond between SL–FA ILs with cell membrane. Moreover, ILs liposomes improve delivery efficiency of Cis and DOX and enhance the combined chemotherapeutic effect. The simple preparation process of the ILs nanoliposome should facilitate the clinical transformation of nanodrugs.