Displaying publications 461 - 480 of 1357 in total

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  1. Rudramurthy GR, Swamy MK
    J Biol Inorg Chem, 2018 Dec;23(8):1185-1204.
    PMID: 30097748 DOI: 10.1007/s00775-018-1600-6
    Nanotechnology advancements have led to the development of its allied fields, such as nanoparticle synthesis and their applications in the field of biomedicine. Nanotechnology driven innovations have given a hope to the patients as well as physicians in solving the complex medical problems. Nanoparticles with a size ranging from 0.2 to 100 nm are associated with an increased surface to volume ratio. Moreover, the physico-chemical and biological properties of nanoparticles can be modified depending on the applications. Different nanoparticles have been documented with a wide range of applications in various fields of medicine and biology including cancer therapy, drug delivery, tissue engineering, regenerative medicine, biomolecules detection, and also as antimicrobial agents. However, the development of stable and effective nanoparticles requires a profound knowledge on both physico-chemical features of nanomaterials and their intended applications. Further, the health risks associated with the use of engineered nanoparticles needs a serious attention.
    Matched MeSH terms: Metal Nanoparticles/therapeutic use*; Metal Nanoparticles/chemistry
  2. Lee KX, Shameli K, Yew YP, Teow SY, Jahangirian H, Rafiee-Moghaddam R, et al.
    Int J Nanomedicine, 2020;15:275-300.
    PMID: 32021180 DOI: 10.2147/IJN.S233789
    Gold nanoparticles (AuNPs) are extensively studied nanoparticles (NPs) and are known to have profound applications in medicine. There are various methods to synthesize AuNPs which are generally categorized into two main types: chemical and physical synthesis. Continuous efforts have been devoted to search for other more environmental-friendly and economical large-scale methods, such as environmentally friendly biological methods known as green synthesis. Green synthesis is especially important to minimize the harmful chemical and toxic by-products during the conventional synthesis of AuNPs. Green materials such as plants, fungi, microorganisms, enzymes and biopolymers are currently used to synthesize various NPs. Biosynthesized AuNPs are generally safer for use in biomedical applications since they come from natural materials themselves. Multiple surface functionalities of AuNPs allow them to be more robust and flexible when combined with different biological assemblies or modifications for enhanced applications. This review focuses on recent developments of green synthesized AuNPs and discusses their numerous biomedical applications. Sources of green materials with successful examples and other key parameters that determine the functionalities of AuNPs are also discussed in this review.
    Matched MeSH terms: Metal Nanoparticles/therapeutic use*; Metal Nanoparticles/chemistry*
  3. Pirouz AA, Selamat J, Iqbal SZ, Mirhosseini H, Karjiban RA, Bakar FA
    Sci Rep, 2017 Sep 29;7(1):12453.
    PMID: 28963539 DOI: 10.1038/s41598-017-12341-3
    Adsorption plays an important role in the removal of mycotoxins from feedstuffs. The main objective of this study was to investigate the efficacy of using magnetic graphene oxide nanocomposites (MGO) as an adsorbent for the reduction of Fusarium mycotoxins in naturally contaminated palm kernel cake (PKC). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to assess the mycotoxins in animal feed. Target mycotoxins included the zearalenone (ZEA), the fumonisins (FB1 and FB2) and trichothecenes (deoxynivalenol (DON), HT-2 and T-2 toxin). Response surface methodology (RSM) was applied to investigate the effects of time (3-7 h), temperature (30-50 °C) and pH (3-7) on the reduction. The response surface models with (R2 = 0.94-0.99) were significantly fitted to predict mycotoxins in contaminated PKC. Furthermore, the method ensured a satisfactory adjustment of the polynomial regression models with the experimental data except for fumonisin B1 and B2, which decrease the adsorption of magnetic graphene oxide (MGO). The optimum reduction was performed at pH 6.2 for 5.2 h at of 40.6 °C. Under these optimum conditions, reduced levels of 69.57, 67.28, 57.40 and 37.17%, were achieved for DON, ZEA, HT-2, and T-2, respectively.
    Matched MeSH terms: Magnetite Nanoparticles/ultrastructure; Magnetite Nanoparticles/chemistry*
  4. Maluin FN, Hussein MZ, Yusof NA, Fakurazi S, Idris AS, Hilmi NHZ, et al.
    PLoS One, 2020;15(4):e0231315.
    PMID: 32315346 DOI: 10.1371/journal.pone.0231315
    Although fungicides could be the best solution in combating fungal infections in crops, however, the phytotoxic level of fungicides to the crops should be tested first to ensure that it is safe for the crops. Moreover, nanocarrier systems of fungicides could play a significant role in the advancement of crop protection. For this reason, chitosan was chosen in the present study as a nanocarrier for fungicides of hexaconazole and/or dazomet in the development of a new generation of agronanofungicides with a high antifungal potent agent and no phytotoxic effect. Hence, the encapsulation of fungicides into the non-toxic biopolymer, chitosan was aims to reduce the phytotoxic level of fungicides. In the present study, the in vivo phytotoxicity of chitosan-fungicides nanoparticles on the physiological and vegetative growth of oil palm seedlings was evaluated in comparison to its pure fungicides as well as the conventional fungicides. The results revealed the formation of chitosan-fungicides nanoparticles could reduce the phytotoxic effect on oil palm seedlings compared to their counterparts, pure fungicides. The chitosan-fungicides nanoparticles were seen to greatly reduce the phytotoxic effect compared to the conventional fungicides with the same active ingredient.
    Matched MeSH terms: Nanoparticles/toxicity; Nanoparticles/chemistry
  5. Yuhana Ariffin E, Heng LY, Tan LL, Abd Karim NH, Hasbullah SA
    Sensors (Basel), 2020 Feb 26;20(5).
    PMID: 32111092 DOI: 10.3390/s20051279
    A novel label-free electrochemical DNA biosensor was constructed for the determination of Escherichia coli bacteria in environmental water samples. The aminated DNA probe was immobilized onto hollow silica microspheres (HSMs) functionalized with 3-aminopropyltriethoxysilane and deposited onto a screen-printed electrode (SPE) carbon paste with supported gold nanoparticles (AuNPs). The biosensor was optimized for higher specificity and sensitivity. The label-free E. coli DNA biosensor exhibited a dynamic linear response range of 1 × 10-10 µM to 1 × 10-5 µM (R2 = 0.982), with a limit of detection at 1.95 × 10-15 µM, without a redox mediator. The sensitivity of the developed DNA biosensor was comparable to the non-complementary and single-base mismatched DNA. The DNA biosensor demonstrated a stable response up to 21 days of storage at 4 ℃ and pH 7. The DNA biosensor response was regenerable over three successive regeneration and rehybridization cycles.
    Matched MeSH terms: Metal Nanoparticles/ultrastructure; Metal Nanoparticles/chemistry
  6. Adebayo IA, Arsad H, Gagman HA, Ismail NZ, Samian MR
    Asian Pac J Cancer Prev, 2020 May 01;21(5):1247-1252.
    PMID: 32458629 DOI: 10.31557/APJCP.2020.21.5.1247
    BACKGROUND: Recently, nanoparticle synthesis by eco-friendly methods has received tremendous attention due to the method advantages and also because of the application of the nanoparticles in cancer research. Therefore, in this study, we synthesized silver nanoparticles from Detarium microcarpum leaf phytochemicals and evaluated its inhibitory effect on pancreatic and cervical cancer cells.

    MATERIALS AND METHODS: Silver nanoparticles (dAgNps) were synthesized by reacting phytochemicals of D. microcarpum leaves with silver nitrate for 12 hours. Cell viability assay was carried out to investigate the cytotoxic effect of dAgNps on HeLa and PANC-1 cells.

    RESULTS: Scanning electron microscopy (SEM) and transmission electron microscopy(TEM) results revealed the average sizes of dAgNps are 81 nm and 84 nm respectively. The x-ray diffraction (XRD) pattern of dAgNps was similar to that of face centered cubic(fcc) structure of silver as reported by joint committee on powder diffraction standards (JCPDS) and fourier-transform infrared spectroscopy (FTIR) analysis showed that some phytochemicals of D. microcarpum such as polyphenols and flavonoids were likely involved in the reduction of Ag+ to form nanoparticles. Finally, cell viability assay revealed dAgNps inhibited PANC-1 and HeLa cell proliferations with IC50 values of 84 and 31.5 µg/ml respectively.

    CONCLUSION: In conclusion, the synthesized nanoparticles from D. microcarpum leaves (dAgNps) have inhibitory effect on pancreatic and cervical cancer cells.

    Matched MeSH terms: Metal Nanoparticles/administration & dosage*; Metal Nanoparticles/chemistry
  7. Mohd Yusof H, Abdul Rahman N, Mohamad R, Zaidan UH, Samsudin AA
    Sci Rep, 2020 Nov 17;10(1):19996.
    PMID: 33204003 DOI: 10.1038/s41598-020-76402-w
    This study aims to utilize the cell-biomass (CB) and supernatant (CFS) of zinc-tolerant Lactobacillus plantarum TA4 as a prospective nanofactory to synthesize ZnO NPs. The surface plasmon resonance for the biosynthesized ZnO NPs-CFS and ZnO NPs-CB was 349 nm and 351 nm, respectively, thereby confirming the formation of ZnO NPs. The FTIR analysis revealed the presence of proteins, carboxyl, and hydroxyl groups on the surfaces of both the biosynthesized ZnO NPs that act as reducing and stabilizing agents. The DLS analysis revealed that the poly-dispersity indexes was less than 0.4 for both ZnO NPs. In addition, the HR-TEM micrographs of the biosynthesized ZnO NPs revealed a flower-like pattern for ZnO NPs-CFS and an irregular shape for ZnO NPs-CB with particles size of 291.1 and 191.8 nm, respectively. In this study, the biosynthesized ZnO NPs exhibited antibacterial activity against pathogenic bacteria in a concentration-dependent manner and showed biocompatibility with the Vero cell line at specific concentrations. Overall, CFS and CB of L. plantarum TA4 can potentially be used as a nanofactory for the biological synthesis of ZnO NPs.
    Matched MeSH terms: Metal Nanoparticles/administration & dosage*; Metal Nanoparticles/chemistry*
  8. Malviya R, Raj S, Fuloria S, Subramaniyan V, Sathasivam K, Kumari U, et al.
    Int J Nanomedicine, 2021;16:2533-2553.
    PMID: 33824590 DOI: 10.2147/IJN.S300991
    PURPOSE: The present study was intended to fabricate chitosan (Ch)-tamarind gum polysaccharide (TGP) polyelectrolyte complex stabilized cubic nanoparticles of simvastatin and evaluate their potential against human breast cancer cell lines.

    MATERIALS AND METHODS: The antisolvent precipitation method was used for formulation of nanoparticles. Factorial design (32) was utilized as a tool to analyze the effect of Ch and TGP concentration on particle size and entrapment efficiency of nanoparticles.

    RESULTS: Formulated nanoparticles showed high entrapment efficiency (67.19±0.42-83.36±0.23%) and small size (53.3-383.1 nm). The present investigation involved utilization of two biological membranes (egg and tomato) as biological barriers for drug release. The study revealed that drug release from tomato membranes was retarded (as compared to egg membranes) but the release pattern matched that of egg membranes. All formulations followed the Baker-Lansdale model of drug release irrespective of the two different biological barriers. Stability studies were carried out for 45 days and exhibited less variation in particle size as well as a reduction in entrapment efficiency. Simvastatin loaded PEC stabilized nanoparticles exhibited better control on growth of human breast cancer cell lines than simple simvastatin. An unusual anticancer effect of simvastatin nanoparticles is also supported by several other research studies.

    CONCLUSION: The present study involves first-time synthesis of Ch-TGP polyelectrolyte complex stabilized nanoparticles of simvastatin against MCF-7 cells. It recommends that, in future, theoretical modeling and IVIVC should be carried out for perfect designing of delivery systems.

    Matched MeSH terms: Nanoparticles/ultrastructure; Nanoparticles/chemistry*
  9. Baharara J, Namvar F, Ramezani T, Hosseini N, Mohamad R
    Molecules, 2014 Apr 15;19(4):4624-34.
    PMID: 24739926 DOI: 10.3390/molecules19044624
    Silver nanoparticles display unique physical and biological properties which have attracted intensive research interest because of their important medical applications. In this study silver nanoparticles (Ab.Ag-NPs) were synthesized for biomedical applications using a completely green biosynthetic method using Achillea biebersteinii flowers extract. The structure and properties of Ab.Ag-NPs were investigated using UV-visible spectroscopic techniques, transmission electron microscopy (TEM), zeta potential and energy dispersive X-ray spectrometers (EDS). The UV-visible spectroscopic analysis showed the absorbance peak at 460 nm, which indicates the synthesis of silver nanoparticles. The average particle diameter as determined by TEM was found to be 12±2 nm. The zeta potential analysis indicated that Ab.Ag-NPs have good stability EDX analysis also exhibits presentation of silver element. As angiogenesis is an important phenomenon and as growth factors imbalance in this process causes the acceleration of several diseases including cancer, the anti-angiogenic properties of Ab.Ag-NPs were evaluated using the rat aortic ring model. The results showed that Ab.Ag-NPs (200 μg/mL) lead to a 50% reduction in the length and number of vessel-like structures. The synthesized silver nanoparticles from the Achillea biebersteinii flowers extract, which do not involve any harmful chemicals were well-dispersed and stabilized through this green method and showed potential therapeutic benefits against angiogenesis.
    Matched MeSH terms: Metal Nanoparticles/ultrastructure; Metal Nanoparticles/chemistry*
  10. Khattak A, Ahmad B, Rauf A, Bawazeer S, Farooq U, Ali J, et al.
    IET Nanobiotechnol, 2019 Feb;13(1):36-41.
    PMID: 30964035 DOI: 10.1049/iet-nbt.2018.5063
    The development of reliable and green methods for the fabrication of metallic nanoparticles (NPs) has many advantages in the field of nanotechnology. In this direction, the present work describes an eco-friendly and cost-effective protocol for the production of silver NPs (AgNPs) using an aqueous extract of Quercus semecarpifolia leaves. Different techniques were carried out for the characterisation of the synthesised AgNPs. The ultraviolet-visible spectroscopic analysis showed the highest absorbance peak at 430 nm. The particle size and structure were confirmed by scanning electron microscopy as well as transmission electron microscopy (TEM) analysis. From TEM imaging, it was revealed that the formed particles were spherical with an average size of 20-50 nm. The crystalline nature of the NPs was determined by X-ray powder diffraction patterns. Thermogravimetry and differential thermal analysis were also evaluated by a temperature increment from 100 to 1000°C. Bio-inspired synthesis of AgNPs was performed for their pharmacological evaluation in relation to the activities of the crude methanolic, n-hexane, chloroform, ethyl acetate, and aqueous extracts. Good cytotoxic activity was exhibited by the green-synthesised AgNPs (77%). Furthermore, the AgNPs were found to exhibit significant antioxidant activity at 300 μg/ml (82%). The AgNPs also exhibited good phytotoxic potential (75%).
    Matched MeSH terms: Metal Nanoparticles/toxicity; Metal Nanoparticles/chemistry*
  11. Ge Y, Lakshmipriya T, Gopinath SC, Anbu P, Chen Y, Hariri F, et al.
    Int J Nanomedicine, 2019;14:7851-7860.
    PMID: 31632005 DOI: 10.2147/IJN.S222238
    BACKGROUND: Gestational diabetes mellitus is a commonly occurring metabolic disorder during pregnancy, affecting >4% of pregnant women. It is generally defined as the intolerance of glucose with the onset or initial diagnosis during pregnancy. This illness affects the placenta and poses a threat to the baby as it affects the supply of proper oxygen and nutrients.

    PURPOSE: Due to the high percentage of affected pregnant women, it should be mandatory to evaluate glucose levels during pregnancy and there is a need for a continuous monitoring system.

    METHODS: Herein, the investigators modified the interdigitated (di)electrodes (IDE) sensing surface to detect the glucose on covalently immobilized glucose oxidase (GOx) with the graphene. The characterization of graphene and gold nanoparticle (GNP) was performed by high-resolution microscopy.

    RESULTS: Sensitivity was found to be 0.06 mg/mL and to enhance the detection, GOx was complexed with GNP. GNP-GOx was improved the sensitive detection twofold from 0.06 to 0.03 mg/mL, and it also displayed higher levels of current changes at all the concentrations of glucose that were tested. High-performance of the above IDE sensing system was attested by the specificity, reproducibility and higher sensitivity detections. Further, the linear regression analysis indicated the limit of detection to be between 0.02 and 0.03 mg/mL.

    CONCLUSION: This study demonstrated the potential strategy with nanocomposite for diagnosing gestational diabetes mellitus.

    Matched MeSH terms: Metal Nanoparticles/ultrastructure; Metal Nanoparticles/chemistry
  12. Aaiza G, Khan I, Shafie S
    Nanoscale Res Lett, 2015 Dec;10(1):490.
    PMID: 26698873 DOI: 10.1186/s11671-015-1144-4
    Energy transfer in mixed convection unsteady magnetohydrodynamic (MHD) flow of an incompressible nanofluid inside a channel filled with saturated porous medium is investigated. The channel with non-uniform walls temperature is taken in a vertical direction under the influence of a transverse magnetic field. Based on the physical boundary conditions, three different flow situations are discussed. The problem is modelled in terms of partial differential equations with physical boundary conditions. Four different shapes of nanoparticles of equal volume fraction are used in conventional base fluids, ethylene glycol (EG) (C 2 H 6 O 2 ) and water (H 2 O). Solutions for velocity and temperature are obtained discussed graphically in various plots. It is found that viscosity and thermal conductivity are the most prominent parameters responsible for different results of velocity and temperature. Due to higher viscosity and thermal conductivity, C 2 H 6 O 2 is regarded as better convectional base fluid compared to H 2 O.
    Matched MeSH terms: Nanoparticles
  13. Lim SP, Pandikumar A, Lim YS, Huang NM, Lim HN
    Sci Rep, 2014;4:5305.
    PMID: 24930387 DOI: 10.1038/srep05305
    This paper reports a rapid and in-situ electrochemical polymerization method for the fabrication of polypyrrole nanoparticles incorporated reduced graphene oxide (rGO@PPy) nanocomposites on a ITO conducting glass and its application as a counter electrode for platinum-free dye-sensitized solar cell (DSSC). The scanning electron microscopic images show the uniform distribution of PPy nanoparticles with diameter ranges between 20 and 30 nm on the rGO sheets. The electrochemical studies reveal that the rGO@PPy has smaller charge transfer resistance and similar electrocatalytic activity as that of the standard Pt counter electrode for the I₃(-)/I(-) redox reaction. The overall solar to electrical energy conversion efficiency of the DSSC with the rGO@PPy counter electrode is 2.21%, which is merely equal to the efficiency of DSSC with sputtered Pt counter electrode (2.19%). The excellent photovoltaic performance, rapid and simple fabrication method and low-cost of the rGO@PPy can be potentially exploited as a alternative counter electrode to the expensive Pt in DSSCs.
    Matched MeSH terms: Nanoparticles
  14. Zubir NA, Yacou C, Motuzas J, Zhang X, Diniz da Costa JC
    Sci Rep, 2014;4:4594.
    PMID: 24699690 DOI: 10.1038/srep04594
    Graphene oxide-iron oxide (GO-Fe3O4) nanocomposites were synthesised by co-precipitating iron salts onto GO sheets in basic solution. The results showed that formation of two distinct structures was dependent upon the GO loading. The first structure corresponds to a low GO loading up to 10 wt%, associated with the beneficial intercalation of GO within Fe3O4 nanoparticles and resulting in higher surface area up to 409 m(2) g(-1). High GO loading beyond 10 wt% led to the aggregation of Fe3O4 nanoparticles and the undesirable stacking of GO sheets. The presence of strong interfacial interactions (Fe-O-C bonds) between both components at low GO loading lead to 20% higher degradation of Acid Orange 7 than the Fe3O4 nanoparticles in heterogeneous Fenton-like reaction. This behaviour was attributed to synergistic structural and functional effect of the combined GO and Fe3O4 nanoparticles.
    Matched MeSH terms: Nanoparticles
  15. Dorniani D, Kura AU, Hussein-Al-Ali SH, Bin Hussein MZ, Fakurazi S, Shaari AH, et al.
    ScientificWorldJournal, 2014;2014:416354.
    PMID: 24737969 DOI: 10.1155/2014/416354
    The efficacy of two nanocarriers polyethylene glycol and polyvinyl alcohol magnetic nanoparticles coated with gallic acid (GA) was accomplished via X-ray diffraction, infrared spectroscopy, magnetic measurements, thermal analysis, and TEM. X-ray diffraction and TEM results showed that Fe3O4 nanoparticles were pure iron oxide having spherical shape with the average diameter of 9 nm, compared with 31 nm and 35 nm after coating with polyethylene glycol-GA (FPEGG) and polyvinyl alcohol-GA (FPVAG), respectively. Thermogravimetric analyses proved that after coating the thermal stability was markedly enhanced. Magnetic measurements and Fourier transform infrared (FTIR) revealed that superparamagnetic iron oxide nanoparticles could be successfully coated with two polymers (PEG and PVA) and gallic acid as an active drug. Release behavior of gallic acid from two nanocomposites showed that FPEGG and FPVAG nanocomposites were found to be sustained and governed by pseudo-second-order kinetics. Anticancer activity of the two nanocomposites shows that the FPEGG demonstrated higher anticancer effect on the breast cancer cell lines in almost all concentrations tested compared to FPVAG.
    Matched MeSH terms: Magnetite Nanoparticles/administration & dosage; Magnetite Nanoparticles/toxicity; Magnetite Nanoparticles/chemistry*
  16. Chong SK, Dee CF, Abdul Rahman S
    Nanoscale Res Lett, 2013;8(1):174.
    PMID: 23590803 DOI: 10.1186/1556-276X-8-174
    Silicon/zinc oxide (Si/ZnO) core-shell nanowires (NWs) were prepared on a p-type Si(111) substrate using a two-step growth process. First, indium seed-coated Si NWs (In/Si NWs) were synthesized using a plasma-assisted hot-wire chemical vapor deposition technique. This was then followed by the growth of a ZnO nanostructure shell layer using a vapor transport and condensation method. By varying the ZnO growth time from 0.5 to 2 h, different morphologies of ZnO nanostructures, such as ZnO nanoparticles, ZnO shell layer, and ZnO nanorods were grown on the In/Si NWs. The In seeds were believed to act as centers to attract the ZnO molecule vapors, further inducing the lateral growth of ZnO nanorods from the Si/ZnO core-shell NWs via a vapor-liquid-solid mechanism. The ZnO nanorods had a tendency to grow in the direction of [0001] as indicated by X-ray diffraction and high resolution transmission electron microscopy analyses. We showed that the Si/ZnO core-shell NWs exhibit a broad visible emission ranging from 400 to 750 nm due to the combination of emissions from oxygen vacancies in ZnO and In2O3 structures and nanocrystallite Si on the Si NWs. The hierarchical growth of straight ZnO nanorods on the core-shell NWs eventually reduced the defect (green) emission and enhanced the near band edge (ultraviolet) emission of the ZnO.
    Matched MeSH terms: Nanoparticles
  17. Chan YS, Mat Don M
    Mater Sci Eng C Mater Biol Appl, 2013 Jan 1;33(1):282-8.
    PMID: 25428073 DOI: 10.1016/j.msec.2012.08.041
    Five species of white rot fungi were screened for their capability to synthesize Ag nanoparticles (AgNPs). Three modes of AgNP bioreduction were developed. Pycnoporus sanguineus is found as a potential candidate for the synthesis of AgNPs with a yield at 98.9%. The synthesized AgNPs were characterized using UV-vis spectroscopy, DLS, FTIR, TEM, and SEM. Results showed that AgNP absorption band was located at a peak of 420 nm. Both the SEM and TEM confirmed that the formation of AgNPs were mainly spherical with average diameters of 52.8-103.3 nm. The signals of silver atoms' presence in the mycelium were observed by SEM-EDS spectrum.
    Matched MeSH terms: Metal Nanoparticles/toxicity; Metal Nanoparticles/ultrastructure; Metal Nanoparticles/chemistry*
  18. Dorniani D, Hussein MZ, Kura AU, Fakurazi S, Shaari AH, Ahmad Z
    Int J Nanomedicine, 2012;7:5745-56.
    PMID: 23166439 DOI: 10.2147/IJN.S35746
    Magnetic iron oxide nanoparticles were prepared using a sonochemical method under atmospheric conditions at a Fe²⁺ to Fe³⁺ molar ratio of 1:2. The iron oxide nanoparticles were subsequently coated with chitosan and gallic acid to produce a core-shell structure.
    Matched MeSH terms: Magnetite Nanoparticles/toxicity; Magnetite Nanoparticles/ultrastructure; Magnetite Nanoparticles/chemistry*
  19. Amran TS, Hashim MR, Al-Obaidi NK, Yazid H, Adnan R
    Nanoscale Res Lett, 2013 Jan 18;8(1):35.
    PMID: 23331761 DOI: 10.1186/1556-276X-8-35
    We present an investigation on a coupled system consists of gold nanoparticles and silicon nanocrystals. Gold nanoparticles (AuNPs) embedded into porous silicon (PSi) were prepared using the electrochemical deposition method. Scanning electron microscope images and energy-dispersive X-ray results indicated that the growth of AuNPs on PSi varies with current density. X-ray diffraction analysis showed the presence of cubic gold phases with crystallite sizes around 40 to 58 nm. Size dependence on the plasmon absorption was studied from nanoparticles with various sizes. Comparison with the reference sample, PSi without AuNP deposition, showed a significant blueshift with decreasing AuNP size which was explained in terms of optical coupling between PSi and AuNPs within the pores featuring localized plasmon resonances.
    Matched MeSH terms: Metal Nanoparticles
  20. Bayat AE, Junin R, Shamshirband S, Chong WT
    Sci Rep, 2015;5:14264.
    PMID: 26373598 DOI: 10.1038/srep14264
    Engineered aluminum oxide (Al2O3), titanium dioxide (TiO2), and silicon dioxide (SiO2) nanoparticles (NPs) are utilized in a broad range of applications; causing noticeable quantities of these materials to be released into the environment. Issues of how and where these particles are distributed into the subsurface aquatic environment remain as major challenges for those in environmental engineering. In this study, transport and retention of Al2O3, TiO2, and SiO2 NPs through various saturated porous media were investigated. Vertical columns were packed with quartz-sand, limestone, and dolomite grains. The NPs were introduced as a pulse suspended in aqueous solutions and breakthrough curves in the column outlet were generated using an ultraviolet-visible spectrophotometer. It was found that Al2O3 and TiO2 NPs are easily transported through limestone and dolomite porous media whereas NPs recoveries were achieved two times higher than those found in the quartz-sand. The highest and lowest SiO2-NPs recoveries were also achieved from the quartz-sand and limestone columns, respectively. The experimental results closely replicated the general trends predicted by the filtration and DLVO calculations. Overall, NPs mobility through a porous medium was found to be strongly dependent on NP surface charge, NP suspension stability against deposition, and porous medium surface charge and roughness.
    Matched MeSH terms: Nanoparticles
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