Characterization,Antiplasmodial and Cytotoxic Activities of Green Synthesized Iron Oxide Nanoparticles Using Nephrolepis exaltata Aqueous Extract

The use of non-toxic synthesis of iron oxide nanoparticles (FeO NPs) by an aqueous plant extract has proven to be a viable and environmentally friendly method. Therefore, the present investigation is based on the FeO NPs synthesis by means of FeCl₃·6H₂O as a precursor, and the plant extract of Nephrolepis exaltata (N. exaltata) serves as a capping and reducing agent. Various techniques were used to examine the synthesized FeO NPs, such as UV-Visible Spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX). The FT-IR studies were used to identify different photoactive biomolecules at 3285, 2928, 1415, 1170, and 600 cm⁻¹ in the wavenumber range from 4000 to 400 cm⁻¹, indicating the -OH, C-H, C-O, C-C, and M-O groups, respectively. The XRD examination exhibited crystallinity, and the average diameter of the particle was 16 nm. The spherical nature of synthesized FeO NPs was recognized by SEM images, while the elemental composition of nanoparticles was identified by an EDX spectrophotometer. The antiplasmodial activity of synthesized FeO NPs was investigated against Plasmodium parasites. The antiplasmodial property of FeO NPs was evaluated by means of parasite inhibitory concentration, which showed higher efficiency (62 ± 1.3 at 25 μg/mL) against Plasmodium parasite if compared to plant extracts and precursor. The cytotoxicity of FeO NPs was also assessed in human peripheral blood mononuclear cells (PBMCs) under in vitro conditions. The lack of toxic effects through FeO NPs keeps them more effective for use in pharmaceutical and medical applications.     

水热合成纳米氧化锡粉体的烧结性能

采用水热合成法合成得到了高纯度氧化锡基纳米粉体材料，以XRD、BET、TEM等手段对合成得到的粉体进行了表征，粉体的晶粒尺寸大小为10～20 nm，分散性能良好。采用无压烧结技术对粉体进行了烧结研究。结果表明，氧化锡粉体粒径的减小提高了粉体烧结活性，烧结助剂Ni离子的加入大大促进了SnO₂的烧结，当Ni离子掺杂为1at%时，SnO₂陶瓷的烧结相对密度最高可达98.6%。     

Selective and Simultaneous Determination of Dihydroxybenzene Isomers Based on Green Synthesized Gold Nanoparticles Decorated Reduced Graphene Oxide

In the present study, we report the simultaneous electrochemical determination of hydroquinone (HQ), catechol (CC) and resorcinol (RC) at gold nanoparticles (Au‐NPs) decorated reduced graphene oxide (RGO) modified electrode. An enhanced and well defined peak current response with a better peak separation of HQ, CC and RC is observed at RGO/Au‐NPs composite than that of RGO and Au‐NPs modified electrodes. The fabricated modified electrode shows a wide linear response in the concentration range of 3–90 µM, 3–300 µM and 15–150 µM for HQ, CC and RC, respectively. The detection limit of HQ, CC and RC is found as 0.15 µM, 0.12 µM and 0.78 µM, respectively.     

纳米氧化铁的电化学合成

采用金属铁为"牺牲"阳极,不锈钢片为阴极,在无隔膜电解槽中,用电化学法合成纳米氧化铁.通过XRD、FTIR、TG DSC及粒径分布等测试方法对所得的纳米粒子进行了表征和分析.实验表明:离心后得到的胶体放置于40℃的真空干燥箱中干燥后,得到无定型纳米氧化铁粒子;经320℃煅烧3h后,粒子转化为γ Fe2O3,平均粒径为22.0nm;进一步提高煅烧温度,在540℃煅烧3h后,可得到平均粒径为35.2nm的α Fe2O3.     

氧化铁磁性纳米粒子固定化酶

纳米粒子作为酶固定化的载体,当其具有磁性时,制备的固定化酶易于从反应体系中分离和回收,操作简便;并且利用外部磁场可以控制磁性材料固定化酶的运动方式和方向,替代传统的机械搅拌方式,提高固定化酶的催化效率。在众多纳米材料中,氧化铁因其在磁性、催化等多方面的良好特性而倍受瞩目。本文对近年来各种氧化铁磁性纳米粒子固定化酶,尤其是固定化脂肪酶和蛋白酶的制备方法及其应用做了较为详细的阐述,对这些氧化铁磁性纳米粒子固定化酶的优缺点和发展前景进行了讨论。     

Iron Oxide Nanoparticles: Biosynthesis,Magnetic Behavior,Cytotoxic Effect

Iron oxide nanoparticles have attracted much attention because of their superparamagnetic properties and their potential applications in many fields such as magnetic storage devices, catalysis, sensors, superparamagnetic relaxometry (SPMR), and high-sensitivity biomolecule magnetic resonance imaging (MRI) for medical diagnosis and therapeutics. In this study, iron oxide nanoparticles (Fe₂O₃ NPs) have been synthesized using a taranjabin (camelthorn or persian manna) aqueous solution. The synthesized Fe₂O₃ NPs were identified through powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), field energy scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX), vibrating-sample magnetometer (VSM) and Raman technics. The results show that the nanoparticles have a hexagonal structure with 20 to 60 nm in size. The cytotoxic effect of the synthesized nanoparticles has been tested upon application against lung cancer cell (A549) lines. It was found that there is no cytotoxic activity at lower concentrations of 200 μg/mL. The ability of the synthesized nanoparticles for lead removal in wastewaters was tested. Results show that highest concentration of adsorbent (50 mg/L) has maximum removal efficiency (96.73 %). So, synthesized Fe₂O₃ NPs can be a good candidate to use as heavy metals cleaner from contaminated waters.     

Biocompatible Multishell Architecture for Iron Oxide Nanoparticles

The coating of super‐paramagnetic iron oxide nanoparticles (SPIONs) with multiple shells is demonstrated by building a layer assembled from carboxymethyldextran and poly(diallydimethylammonium chloride). Three shells are produced stepwise around aggregates of SPIONs by the formation of a polyelectrolyte complex. A growing particle size from 96 to 327 nm and a zeta potential in the range of +39 to ?51 mV are measured. Microscopic techniques such as TEM, SEM, and AFM exemplify the core‐shell structures. Magnetic force microscopy and vibrating sample magnetometer measurements confirm the architecture of the multishell particles. Cell culture experiments show that even nanoparticles with three shells are still taken up by cells.

     

钴掺杂的磁性氧化铁纳米粒子的可控合成

通过油酸盐前驱体高温热解法制备出大小均匀的钴掺杂四氧化三铁球形纳米粒子, 其钴/铁摩尔比可以通过调节油酸钴与油酸铁的比例进行调变. 当产物中钴/铁摩尔比从0.024增加到0.156, 所制备的氧化铁纳米粒子的饱和磁矩从39 emu·g^-1逐渐减小到30 emu·g^-1, 而矫顽力从0 Oe升至190 Oe. 在305℃下, 随着反应体系的热解时间由0.5 h 增加到3 h, 所制备出的氧化铁纳米粒子尺寸逐渐由7 nm增加到14 nm. 热解时间较短时, 以高价态的四氧化三铁的晶型为主, 辅之以少量的氧化亚铁; 热解时间增加至2 h, 产物的晶型为四氧化三铁和氧化亚铁的复合物; 而继续增加热解时间至3 h, 除四氧化三铁和氧化亚铁之外, 还出现少量的零价态的CoFe合金, 说明铁(钴)元素经历了由三价到二价, 最后被还原为零价的过程. 随着反应温度的升高, 产物的尺寸逐渐增大, 同时产物中氧化亚铁的含量增多.     

铁的氧化物纳米颗粒及其组装体的化学制备

铁的氧化物纳米颗粒作为一种重要的磁性纳米颗粒在磁记录材料、磁性液体、催化、尤其是生物医用领域有着广泛的应用前景,因而受到了研究者们极大的关注。本文对铁的氧化物磁性纳米颗粒的化学制备方法进行了综述,将其归结为复分解和热分解两种策略;总结了近期含铁的氧化物纳米颗粒组装体的研究进展,并对未来的发展做了展望。     

Thermal Plasma Synthesis of Superparamagnetic Iron Oxide Nanoparticles

Superparamagnetic iron oxide nanoparticles were synthesized by injecting ferrocene vapor and oxygen into an argon/helium DC thermal plasma. Size distributions of particles in the reactor exhaust were measured online using an aerosol extraction probe interfaced to a scanning mobility particle sizer, and particles were collected on transmission electron microscopy (TEM) grids and glass fiber filters for off-line characterization. The morphology, chemical and phase composition of the nanoparticles were characterized using TEM and X-ray diffraction, and the magnetic properties of the particles were analyzed with a vibrating sample magnetometer and a magnetic property measurement system. Aerosol at the reactor exhaust consisted of both single nanocrystals and small agglomerates, with a modal mobility diameter of 8?C9?nm. Powder synthesized with optimum oxygen flow rate consisted primarily of magnetite (Fe₃O₄), and had a room-temperature saturation magnetization of 40.15 emu/g, with a coercivity and remanence of 26 Oe and 1.5 emu/g, respectively.     

Green Synthesized Zinc Oxide Nanoparticles Based on Cestrum diurnum L. of Potential Antiviral Activity against Human Corona 229-E Virus

SARS-CoV-2 has caused more than 596 million infections and 6 million fatalities globally. Looking for urgent medication for prevention, treatment, and rehabilitation is obligatory. Plant extracts and green synthesized nanoparticles have numerous biological activities, including antiviral activity. HPLC analysis of C. dirnum L. leaf extract showed that catechin, ferulic acid, chlorogenic acid, and syringic acid were the most major compounds, with concentrations of 1425.16, 1004.68, 207.46, and 158.95 µg/g, respectively. Zinc nanoparticles were biosynthesized using zinc acetate and C. dirnum extract. TEM analysis revealed that the particle size of ZnO-NPs varied between 3.406 and 4.857 nm. An XRD study showed the existence of hexagonal crystals of ZnO-NPs with an average size of 12.11 nm. Both ZnO-NPs (IC₅₀ = 7.01 and CC₅₀ = 145.77) and C. dirnum L. extract (IC₅₀ = 61.15 and CC₅₀ = 145.87 µg/mL) showed antiviral activity against HCOV-229E, but their combination (IC₅₀ = 2.41 and CC₅₀ = 179.23) showed higher activity than both. Molecular docking was used to investigate the affinity of some metabolites against the HCOV-229E main protease. Chlorogenic acid, solanidine, and catchin showed high affinity (−7.13, −6.95, and −6.52), compared to the ligand MDP (−5.66 Kcal/mol). Cestrum dinurum extract and ZnO-NPs combination should be subjected to further studies to be used as an antiviral drug.     

Dark Fermentative Hydrogen Production from Neutralized Acid Hydrolysates of Conifer Pulp

Concentrated acid hydrolysis of cellulosic material results in high dissolution yields. In this study, the neutralization step of concentrated acid hydrolysate of conifer pulp was optimized. Dry conifer pulp hydrolysis with 55?% H₂SO₄ at 45?°C for 2?h resulted in total sugar yields of 22.3?C26.2?g/L. The neutralization step was optimized for solid Ca(OH)₂, liquid Ca(OH)₂ or solid CaO, mixing time, and water supplementation. The highest hydrogen yield of 1.75?mol?H₂/mol glucose was obtained with liquid Ca(OH)₂, while the use of solid Ca(OH)₂ or CaO inhibited hydrogen fermentation. Liquid Ca(OH)₂ removed sulfate to below 30?mg SO₄ ^2?/L. Further optimization of the neutralization conditions resulted in the yield of 2.26?mol?H₂/mol glucose.     

Porous Molybdenum Carbide Nanostructures Synthesized on Carbon Cloth by CVD for Efficient Hydrogen Production

Molybdenum carbide (Mo₂C) is a promising noble-metal-free electrocatalyst for the hydrogen evolution reaction (HER), due to its structural and electronic merits, such as high conductivity, metallic band states and wide pH applicability. Here, a simple CVD process was developed for synthesis of a Mo₂C on carbon cloth (Mo₂C@CC) electrode with carbon cloth as carbon source and MoO₃ as the Mo precursor. XRD, Raman, XPS and SEM results of Mo₂C@CC with different amounts of MoO₃ and growth temperatures suggested a two-step synthetic mechanism, and porous Mo₂C nanostructures were obtained on carbon cloth with 50 mg MoO₃ at 850 °C (Mo₂C-850(50)). With the merits of unique porous nanostructures, a low overpotential of 72 mV at current density of 10 mA cm⁻² and a small Tafel slope of 52.8 mV dec⁻¹ was achieved for Mo₂C-850(50) in 1.0 m KOH. The dual role of carbon cloth as electrode and carbon source resulted into intimate adhesion of Mo₂C on carbon cloth, offering fast electron transfer at the interface. Cyclic voltammetry measurements for 5000 cycles revealed that Mo₂C@CC had excellent electrochemical stability. This work provides a novel strategy for synthesizing Mo₂C and other efficient carbide electrocatalysts for HER and other applications, such as supercapacitors and lithium-ion batteries.     

聚天冬氨酸修饰对磁性氧化铁纳米粒子稳定性及脑MRI造影效果的影响

<正>超顺磁性氧化铁(Superparamagnetic iron oxide,SPIO)作为医用磁共振成像(Magnetic resonance imaging,MRI)造影剂,可以有效地改变人体组织中质子的自旋-自旋弛豫时间,从而增强磁共振成像的对     

Magnetically Guided Protein Transduction by Hybrid Nanogel Chaperones with Iron Oxide Nanoparticles

Protein pharmaceuticals show great therapeutic promise, but effective intracellular delivery remains challenging. To address the need for efficient protein transduction systems, we used a magnetic nanogel chaperone (MC): a hybrid of a polysaccharide nanogel, a protein carrier with molecular chaperone‐like properties, and iron oxide nanoparticles, enabling magnetically guided delivery. The MC complexed with model proteins, such as BSA and insulin, and was not cytotoxic. Cargo proteins were delivered to the target HeLa cell cytosol using a magnetic field to promote movement of the protein complex toward the cells. Delivery was confirmed by fluorescence microscopy and flow cytometry. Delivered β‐galactosidase, inactive within the MC complex, became enzymatically active within cells to convert a prodrug. Thus, cargo proteins were released from MC complexes through exchange interactions with cytosolic proteins. The MC is a promising tool for realizing the therapeutic potential of proteins.     

Durable Mesenchymal Stem Cell Labelling by Using Polyhedral Superparamagnetic Iron Oxide Nanoparticles

Small polyhedral superparamagnetic iron oxide (SPIO) nanoparticles (<10 nm) coated with a thin layer of silica were prepared (SPIO@SiO₂ and SPIO@SiO₂‐NH₂). Surface modification of the small polyhedral silica‐coated SPIO nanoparticles with amines led to substantially higher mesenchymal stem cell (MSC) labelling efficiency without the use of additional transfecting agents. Therefore, amine surface‐modified nanoparticles (SPIO@ SiO₂‐NH₂) appeared to be the preferred candidate for MSC labelling. In vitro studies demonstrated that controlled labelling of SPIO@SiO₂ and SPIO@SiO₂‐NH₂ did not cause MSC death or proliferation inhibition. MSCs labelled with SPIO@SiO₂‐NH₂ nanoparticles retained differentiation potential and showed osteogenic, adipogenic and chondrogenic differentiations. The noncytotoxic polyhedral SPIO@SiO₂‐NH₂ nanoparticle‐labelled MSCs were successfully implanted in rabbit brain and erector spinae muscle, and demonstrated long‐lasting, durable MRI labelling efficacy after 8–12 weeks.     

Green Synthesis of Ag Nanoparticles by Callicarpa Maingayi: Characterization and Its Application with Graphene Oxide for Enzymeless Hydrogen Peroxide Detection

A facile green synthesis of silver nanoparticles (AgNPs) was achieved using aqueous leaf extract of Callicarpa Maingayi as a reducing and stabilizing agent during the synthesis from its salt solutions. The synthesized silver nanoparticles were analyzed with transmission electron microscopy (TEM), X‐ray diffraction (XRD) and energy dispersive spectrometer (EDS). XRD study shows that the particles are crystalline in nature with face centered cubic geometry. The crystallite size obtained from XRD is about 15 nm which is in agreement well with the TEM results. A new nanostructure sensor was constructed by immobilizing silver nanoparticles and graphene oxide (AgNPs‐GO) composite film on a glassy carbon electrode (AgNPs‐GO/GCE). It was found that the AgNPs‐GO composite exhibits good catalytic activity toward the reduction of hydrogen peroxide (H₂O₂), leading to an enzymeless sensor with a fast amperometric response time of less than 5 s, high selectivity, good reproducibility and stability. The linear range was 5.0 μM to 700 μM with a detection limit of 0.6 μM (S/N = 3).     

Fe含量对层状K-Fe-Ti金属氧化物光催化制氢性能的影响

以KNO3,Fe(NO3)3·9H2O,TiO2为原料,通过固相反应,制备出一种新型的光催化材料K-Fe-Ti层状金属氧化物,考察了这种催化剂的光催化制氢性能.发现Fe的含量并不是影响催化剂光催化制氢性能的主要因素,而催化剂的结构是影响光催化制氢效率的主要原因,不同牺牲剂对其光催化制氢性能也有较大的影响.     

磁性铁氧化物纳米粒子表面功能化及其应用

表面功能化的磁性铁氧化物纳米粒子是一种新型功能材料,可应用于各种生物活性物质如蛋白质、DNA等的富集和分离,药物的磁靶向,以及疾病的诊断和治疗等许多领域.本文在总结近年来国内外有关功能化磁性铁氧化物纳米粒子研究成果的基础上,阐述了功能化磁性铁氧化物纳米粒子的结构类型、特点、目前的各种功能化制备方法以及相关应用最新研究进展,指出了当前研究中的主要发展方向和仍需要解决的问题.